Document KGYXMdm89v53bzppYey3ZNKkK

INTRA-COMPANY CORRESPONDENCE o Subj*e Mr. R. F. Shannon, Granville 0. W. Pfeifer, Granville ASBESTOS AM05ITE AND CHRYSOTILE Doi. jyi6f 1967 cc: Mr. M. Hardwick, Berlin There has been a need to have some basic information available on asbestos, both amosite and chrysotile, in the general knowledge area. Specifics --as to specifications, etc. are in other detailed sources. This study had as its beginning the information concerning amosite asbestos, in its various grades, as obtained from North American Asbestos Corporation. This was followed by its milling, preparatory to its inclusion as a rein forcement and an aid to thermal conductivity in Kaylo slurry for the characteristics of the final product. As we continued, we added other sections, which we thought were pertinent and these were included to the volume of the present project makeup. CWP/ris 01 040 117.4  S T0 S H 1 A HOSITE AMD CHAYSOT! L SHANNON AS&ESTOS AMOSITE CHRVSOTILE. 01 040 1172 table of contents 01 040 1173 PART X amosite. asbestos 01 040 1170 A33 EST0 S A MOSITE AND CHRYSOTILE TABLE OF CONTENTS FART I -- AMOSITE ASBESTOS Section 1 -- Correspondence Section 2 -- Asbestos, The Raw Material Section 3 -- Test Methods For Blue and Amosite Asbestos Fibers PART II -- CHRYSOTILE ASBESTOS Section 4 -- Moody Fibre Fluffer Section 3 -- Milling Asbestos Section 6 -- Recovery of Raw Materials Section 7 -- Canadian Chrysotile Asbestos Classification PART III -- AMOSITE AND CHRYSOTILE ASBESTOS Section 8 -- The Asbestos Factbook Section 9 -- Asbestos, A Mineral of Unparalleled Properties 01 040 1170 SECTION-n. C0fcR.ES PON O E.N C E_ 01 040 1177 ?A A M0S I T ASB EC L 0s SECTION 1 -- CORRESPONDENCE A. DR. GAZE'S REPLY TO PALLMAN MILL PROCESSING OF AMDSITE Page 7 -- The outstanding fact is that the amosite asbestos is milled dry. It has been obvious for years that by wet milling to open amosite fibers, we have been destructive to the fiber length and have further shortened the already short fiber length. Page 8 -- Here are listed the factors determining the set up of the mill for best results. This will be most helpful information for us. The Pallman Mill people in North Jersey can supply us with informa tion on chrysotile asbestos. B. LD3 AMOSITE Page 13 -- We can explore the availability and cost of LD3 amosite fibers when we get along with the Pallman Mill trials. By using this longer fiber as a percentage in a blend with shorter amosite fibers, we may increase impact strength in the final Kaylo product and effect a lower asbestos cost at the same time. As anxious as everyone is to eliminate asbestos from Xaylo the arrival at this state of rein forcement is a few years away, so the work on amosite reinforcement for product strength, as well as cost improvement, should go forward at full speed. C. FALLMAN PULVERIZERS, INCORPORATED Page 15 ~ We shall immediately contact these people in Hoboken and secure cost of processing different grades of amosite for fiber opening at various recommended settings of the Pallman Mill. Several tons of each grade should be sent to them, opened and then processed in regular production at Berlin. Also, several experimental batches should be undertaken at Kaylo Research on blends of amosite Pallman opened fiber, so as to 'bulls-eye' the target runs in the plant for the optimum results. 01 040 1178 SECTION 1 -- CORRESPONDENCE (lont.) 3. PA1IHAN MILL Page 19 -- The picture here shows the rotor and the swinging, stationary, .counted head. At first glance it is to be noted that the design is consid erably different than the Bauer Mill and the shearing action to open the fiber is less direct and abrasive than the Bauer. On the following pages are descriptions of the mill and its operations. Of particular note is the inclusion of a magnetic separator for trapping of 'tramp iron', which is most important for other Eaylo equipment protection, particularly pumps. We shall secure quotations from them on costs on suggested mills for Berlin's capacity per hour, feeding and discharging methods and equipment, etc. E. DR. GAZE'S VISIT TO GRANVILLE Page 26 -- Dr. Jerome, of North American Asbestos, brought Dr. C-aze, of Cape Asbestos, to Granville and talked with Dr. Kalousek and, evidently, Marsh Armstrong as well, in October 1961, regarding the milling of asbestos. Unfortunately, Messrs. Kalousek and Armstrong are no longer available for comment. However, Kalousek's memo is important in that it states rather emphatically Dr. Gaze's reaction to Berlin's wet asbestos opening process compared to Cape's dry method and their poor results from similar wet milling experiments. You will note that Dr. Gaze was dubious about using the hydrapulper in the mixing of the asbestos into the slurry. He was likewise very definite in his disapproval of the use of centrifugal pumps, because of shortening the fiber length, due to the shearing action of the impellers. We recall several visits of Dr. Jerome to Berlin, both with and without Bob Cryor of NAAC, and he was familiar with the Kaylo operation, particularly the mixing area, and constantly urged the elimination of the wet Bauer milling for an improvement in fiber length. The arguments pro and con of wet vs dry milling have gone on in Kaylo for years and prior to 1958 there was a definite position of Kaylo's technical people in support of wet milling. Strength, until extenders to the batch were introduced for various reasons, were adequate and better than competition, with the exception of J-M. This debate has since continued intermittantly without any direct action being taken. It is significant to note that all of the other calcium silicate manufacturers use dry milling to open their asbestos. J-M has their own design of picker for their first opening of fiber, patterned after such equipment at their Thetford mine. Baldwin-Ehret-Hill uses a Sprout-Waldron attrition mill for coarse grinding amosite and finer shredding of chrysotile for suspension purposes. 01 040 1179 ?IQN CORRESPONDENCE (Cont.j ?. SPROUT-WALDRON EQUIPMENT FOR OPENING ASBESTOS FIBERS Page 26A -- A description of the equipment manufactured by Sprout-Waldron for opening asbestos fibers for Baldwin-Shret-Hill is self-explanatory on the above numbered page. To our knowledge this calcium silicate manufacturer is the only other one that uses a hydrapulper for mixing purposes. There is a definite reason for this for they bought much of the Sayreville Kaylo equipment when it was dismantled and their Director of Research was then, and still is, Jack McAllister, who was Production Manager for us at Sayreville until late 1952. The 3-E-H process is the Pabco vertical machine, which is under a license agreement to them. The experimental vertical casting machine at Berlin several years ago was a take off from this patent. R. F. Shannon made some experiments in 1961-196? with W3 asbestos opened by Sprout-Waldron equipment, with results that were better than wet milled Bauer opened amosite. G. PROCTOR AND SCHWARTZ EQUIPMENT FOR OPENING AMOSITE ASBESTOS R. F. Shannon, in early 1962, contacted Proctor and Schwartz, Philadelphia, who manufacture various types of equipment used in the textile processing, such as feeders, shredders, pickers and carders. W3 amosite was taken to their laboratory and opened on a feeder, shredder, carding machine and in a combination of feeder-picker and feeder-shredder. When dry opened amosite was milled through the wet process at Berlin, namely hydrapulper, centrif ugal pumps, etc., a much lower result in drop test strength was obtained than when the same opened W3 amosite was mixed and poured in the Research Laboratory at Granville. This very definitely pointed out the attrition to fiber length, after being dry opened that was occurring at these points in the 3erlin mixing and slurry transport system. The laboratory results gave best strength from the feeder-picker combination. 11 of Proctor and Schwartz opened W3 amosite gave higher strength results than dry opened W3 amosite with Devil Tooth Bauer Mill or Sprout-Waldron fiberizer. H. AMOSITE GRADE FIBRE CANADIAN BOX TEST Pages 27 and 28 -- CANADIAN BOX TEST SAMPLING AND SIEVE SIZES Amosite Grade LD3 W3 S33 <N 1--1f--1 Y Mesh 0 Mesh 0 It 10 10 Mesh 1 1? 3 Pan 0 1 z .3 01 040 1180 SECTION 1 -- CORRESPONDENCE (Cont.) AMOSITE GRADE E3RE CANADIAN BOX TEST (Cont.) The three sizes listed here point out the big difference in fiber length between LD3 and 333 as well as between W3 and S33 If LD3 is still available at the same price as W3, a blend may be devised of LD3 and 333 that will give longer fiber for higher strengths at a lower cost than for Also, W3 and S33* when Pullman Mill opened, may give a lower cost with increased strengths than present W3, wet Bauer Mill opened, and certainly better results than present W3-S33 combination, wet Bauer milled. A careful and studied observance of longer fiber effect on clogging of 3/8 inch pouring spout openings will have to be made and not an opinion accepted prior to testing of what the result will be. It may be necessary to redesign the pouring nozzle and good results are- a possibility from this investigation as well. It may be something to consider for instance, to try to eliminate the 180 direction travel of the slurry from the input side of the nozzle to the discharg slot. An overhead mounting with a vertical charge and discharge style nozzle may be a revolutionary breakthrough, affecting not only strength, but surface finish as well. It would be well worth a trial! Such a beginning with an 8 inch length pouring nozzle could well develop into the 36 inch length pouring spout, with all of its advantages. 01 040 11B1 PUBLISHED BY NiOPTH AMERICAN ASBESTOS CORPORATION 141 Wost Joc*&on Sivo. /Cr>icao, iiimots 6C604 / Pnor (312) 922*7435 / CdO* Aoores*;NCRAMCO. CriiCAGO Voi. I - No, - juiy 1 isoo NEWSLETTER? -- WHY? The NAAC monthly Newsletter is intended to provide anmcditional information service for those interested in Amosite and Crocidoifte Asbestos. The Newsletter is an effort to extend and to increase the effectiveness of NAAC communications, as a means of keeping in touch with customers and friends in addition to telephone contact, correspondence and personal visits. The Newsletter will regularly include general information about Amosite and Crocidolite (Blue) Asbestos, news of technical developments, fibre availability, shipping and transportation as related to these fibres, and other items of interest. We will keep it brief. We hope the Newsletter will become a useful extension of NAAC services. If there are others in your company who should be on the mailing list, please have them write or simply complete the enclosed reply card. NAAC ? -- WHO? WHAT? WHERE? North American Asbestos Corporation, a part of the Cape Asbestos Group, is engaged exclusively in the marketing of Amosite and Crocidolite Asbestos, both mined in South Africa. We do not mine or market Chrysotile Asbestos. Amosite and Blue Fibres are frequently used in conjunction with Chrysotile, but ordinarily do not compete with Chrysotile -- end uses are usually different. The NAAC marketing territory is the United States, Canada, Mexico, Central America, and the Caribbean area. We regularly bring Amosite and Crocidolite into all major ports in North America, including Montreal, Boston, Philadelphia, New York, Baltimore, Norfolk, New Orleans, Mobile, Galveston/Houston, Tam pico, Vera Cruz, Los Angeles, Sar. Francisco, Seattle/Tacoma, and Vancouver. Inventories of certain grades of Amosite and Crocidolite are regularly warehoused in Philadelphia, and occasionally in New Orleans, and Los Angeles. We strive to provide continuous and up-to-date information on Amosite and Crocidolite avail ability in respect to supplies at the mines, in transit, and in warehouses. We can frequently adjust or divert inbound shipments to meet emergency requirements. Cur parent company. The Cape Asbestos Company Limited/London, through exten sive mining operations in-South Africa, is the largest producer of Amosite and Blue Asbestos. NAAC is the largest importer/marketer of these fibres in the Americas. Ql 040 1182 No:" America.-, A-., .--.z Ca.- i.-asior. is a rr.exocr of tnc Cape Asocs:as jroup of companies. I' Republic of South Africa Ekmttii Country Boundaries c**iisj2 Provincial Boundaries CAp Aabntot Oroap of Cotapool-- Mia-- ud Offio-- in tho RopubUe of South Afries C*p* Cw* fc**0i*w*>> *** * Jtototottoa* .*** *hw Omrdlh>f*c* *T(***** P*mn**.n*.*****--* to. *MCHmmii*>,!**n>d mm t Kn***. Htoiwu. to PwAi * Cto* Pr*****. md PEt<oWuwl -- Mto*U<r w<mm bM Cto* T*m m mantmaih *m** 01 040 1183 ,w. Railways - Rivers 5P Company Mining Towns AMOSITE IN THERMAL INSULATION APPLICATIONS A large percentage of the world's Amosite production is used in manufacturing thermal insulation. These insulations take many forms, the most important o which is rigid molded pipe and block insulation for high temperature service. Such inmi.itiou must have liiji therm.il efficiency, relatively high strength, low density, heat stability tip to 1.2'>0 decrees or more, and dur.ibilirv over the lone service life of the insulation. There are two principal types of rigid molded insulation in which Amosite is either an essential or a predominant component. One type is calcium silicate insulation composed of asbestos, diatomaceous earth, silica and lime. This product results from chemical conversion of the basic components into calcium silicate, followed bv wet molding with subsequent autoclaving before drying and finishing. Calcium silicate insulation is notable for high insulating efficiency, and for its smooth finish and dimensional accuracy. The other important type is molded Amosite insulation, which is produced by a process of accumulat ing Amosite fibre combined with inorganic binders on mandrels of suitable size, using a semi-wet form ing process. Produced in manv different countries, molded Amosite insulation is well known tor its high insulating values, rugged strength and durability. Amosite is a major component of these high quality insulations primarily because of its heat resistance and reinforcing characteristics, but also due to its great bulkiness. No other mineral fibre provides the Trs 4same combination of strength, heat resistance, stability and durabilQy|at e0Dj|c0iic Amosite's unusual performance characteristics also make it an ideal material for use in flexible and wrap-around types of thermal insulation. It also is used in combination with mineral wool, vermicu- !-___ ____U__ ... J ............1 C:t___ ___ _____ . -I _ _____: I V ____ _ C :........I _ X' rxsT'rxo maxual A> i--'. L-COOC* *r*.3>"jCi*Co l" ZG. .OC ; OilC. Oil} pCk*'- 01 o j. r - :c 'O^*i,.'1u.o0 '7 ; V* a ^ i.rcr.t group, ar.c. rcspor.ai.OiC ter v/or-u m or^c:-v ^ ^ C.. -ky (.uu..S.0C. . c.--... O-- --.e ... c-- OS" S ci-- .....OS ..i >.iov>bi>uS --' --0 -- C . i ...o ^ *> * * C Cm -- *0.. S- V- - W* kit* Oi *1iUa iiy to scientific and technical personnel, parti :uiarly :hose **S ` u* '..iC :cs;m: i*c* *0.0 o it o wGry ovolu.o.u ion o* clsoosuGS zioz*os* ns intow tne names o: tr.ose m, your organization v/no snoum nave a copy. * he new manual should prove to be a valuable companion publication to the volume, "Test ing Procedures tor Chrysotilc Asbestos Fibres", a widely recognized manual issued jointly by Asbestos Textile Institute, Mineral Fibre Products Bureau, and Quebec Asbestos Mining Association. U.S. GOVERNMENT STOCKPILE DISPOSAL The U. S. Government,, through uor.ort. cervices Acminiotraticn, nas autnorized the disposal ox a substantial tonnage of both Amosite and Crocidolite now considered to be in excess of emergency stockpile requirements. The Amosite and Blue Asbestos is being released along with excess tonnage of some fifty other strategic minerals in the Government Stockpile. XAAC is cooperating with GSA to establish a means of moving the surplus tonnage into industry channels with minimum disruption of normal commercial relationships, and'with due attention to the age and condition of the surplus stocks. Part of this has been in stockpile since 1951, during whic; time standard gradings, through improved milling techniques, have changed and improved considerably. It is possible GSA may wish to rely on NAAC as a principal agency in the cisposa program, but as yet no decision has been reached. Discussions are continuing. .Meanwhile GSA will, from time to time, offer portions of the surplus material on oublic bid. More on this later. FIBRE SUPPLY The tight supply position on certain grades of Amosite, partic ularly grades DX, Dll, W3, K3, S33, GX, A1Q, continues. For the long ar.d medium-long grades -- DX,D11, W3,K3 -- the position is expected to ease during' the next ninety days.due to increased production and availability of stockpile material. The shorter grades -- S33, GK, A.10 -- will continue to be difficult until the early part of 1967 when additional production becomes available. Blue .Asbestos is in fairly good balance in supply and demand for most gradings. Inventories are relatively low, but mine shipments are keeping up well with current requirements. Long Blue gradings for spinning purposes are in tight supply. LaT ~JS 1-Ic.AP. FROM YOU. Call or write XAAC if you have questions or need assistance on any problem relating to Amosite or 31ue Asbestos. ;c:; >; i'fi sji i'fi # 01 040 1185 3. BOARD OF TRADE BUILDING, CHICAGO, ILLINOIS 60604 PHONE. (3X3 222-7435 CABLES. NORAMCO, CHICAGO December 21, 1965 Mr. O. W. Pfeifer Owens-Corning Fiberglas Corp. Technical Center Granville, Ohio Dear Mr. Pfeifer: Referring to your letter of December 7, I now have further word from Dr. Gaze in London concerning the questions you raised about the Pallmann Mill. I enclose copy of his letter of December 16, and, after you study this, if you find that there is further information you think we can supply please let me know. With kind regards and very best wishes for the Holidays. Very truly yours, NORTH AMERICAN ASBESTOS CORPORATION RECryor/jc end. 01 040 11S6 December 7, 1965 ::r. ?..D. Cryor, President forth American Asbestos Corporation Dosrd of Trade Building Chicago, Illinois 60604 Tear Hr. Cryor: be have your latter of December 1, 1965. He have studied the brochure on the Hallman bill, be have several questions for you to secure answers, if you will: 1. V.Te would deduce fron Hr. Gaze's letter that Cape Asbestos uses a Hallman Mill to open their ar.osita fibers, in the manufacture of CAPOSIL Insulation? Is this done by the dry or wet method? 2. Has Dr. Gaze had any experience in opening chrysctile asbestos with a Hallman Hill? Perhaps CAPOSIL uses only amosito asbestos fibers? As you know we use both amosite and chrysotile and in our case, could wo use the Hallman Mill for oponir.g both types? If both types of asbestos fibers are to be opened, could Dr. Gaze secure mill settings for the various gradings of both types? 3. Is a picker or any other type of fibor opening equipment used in conjunction with the Hallman Mill? 4. Could wo propose to Dr. Gaze that ho have Hr. McParlar.e write concerning details of speeds ana adjustments? 5. Does the Pallman Hill have any percentage of fiber length attrition loss, and if so docs this vary between chrysotile and amosite types because of differences of original stiffness of the fibers? 6. Me are having our Purchasing Agent get in touch with ?ailr.an, in Hoboken, for further information. talked with Dorse;7' Hclao regarding ID3 substitution for a possible mortage xn .0 iding in l?u, and had him call the Plant for their ."'--rovai to secure from you about 10 tons for trials. .or ar.v nrocossmg * ** * or rising problem occurrence. Me also wrote to Mr. Hardwick;, at Berlin, suggesting he make these trials, in order to determine the adaptability 01 040 1187  * t *1 `*M i'i >**. k .. j ,`i'vi - * v' v a, in <!.o C.ipo or;'.-ui ' (\ \ . ' w\..0 m<J ** j--.'-.l.W 3jl U a. V* m | . c,f.~ t. Cwens-Corning FIESFGLAS Corporation c;.p/rd Pfeifer n w 01 040 1188 THE CAPE ASBESTOS COMPANY LIMITED r 114 & 116 PARK STREET- LONDON W.l. TCLCQRAMS: INCORRUPT LONOON TCLCX TELCPMONC'- CROSVCNOR 6022 TCLCX N* 23760. 16th December, 1965 0C2CI]965 Dear Bob, The answers to the questions from Owens Corning which you enclose with your.letter of 9th December are as follows : Ballmann Mill i. We are, in fact, using the Pallmann Mill to open Amosite fibre for the production of Caposite but we .are satisfied, from our pilot scale trials, that the mill is equally suitable for the preparation of Amosite for Caposil and indeed for any other process that we know of for which Amosite is used (with the possible exception of the very long textile fibres with which Owens Corning are not concerned). '/. We are already replacing our existing mills for other processes by Pallmann's and I believe it is ^ only a matter of time and convenience before a complete substitution is made. The Pallmann opening is carried out entirely dry. ii. We have carried out experiments with Chrysotile using the mill and all our results were favourable. We have little doubt that the mill will be equally satisfactory for processing Chrysotile although we have not pursued this to any great extent since the processing of Chrysotile is not a large activity in any of our plants. So far as the mill settings are concerned, Mr. McParlane has provided the following information : The three variables which influence the degree of fibre opening are 01 040 1189 i. / (a) The rotor diameter \ 1if (b) The rotor speed (c) The diameter of the confining ring i (d) The type and grade of crude ii ore For all grades of Amosite we have found that a rotor diameter of 720 mm and a speed of 2,600 r.p.m. produce the best results. The bore of the confining ring needs to be related to the resistance of the system through which the fibre is discharged from the mill. For any one installation, a few experimental runs will quickly determine the most suitable size of ring to be used for any particular grade of fibre. For example, our Pallmann Mill is connected to a system of ducting which terminates in a cyclone, the whole producing a resistance of about 3`t inches water gauge. Under these circumstances, we have determined that for the opening of DX, Dll and LD3 fibres, the best results are achieved r __with a confining ring of 4-50 mm diameter. iii. Ho other opening equipment is used in conjunction with the Pallmann Mill, nor indeed should it be necessary. iv. 7/e hope that the comments given under paragraph ii will answer this question. v One of the major virtues of the mill is that it will open fibres to a consistent degree and without the production of fluffy material. One of our reasons for choosing this mill, after an extensive search, is that it damages fibre less than any other mill that we have encountered. We would expect similar results with processing Chrysotile Asbestos. vi. Y/e have been given to understand that the Pallmann organisation in Hoboken have had considerable experience in the opening of Chrysotile Asbestos, but are unlikely to have much knowledge of the application of their mills to Amosite fibres. If, therefore, it is felt that we can provide further information on the subject, we shall be pleased to do so. vl 040 1190 Yours sincerely, Mr. R.3.. Cryor, North American Asbestos Corporation, Board of Trade'Building, Chxcago. NORTH AMERICAN ASBESTOS CORPORATION BOARD OF TRADE BUILDING, CHICAGO, ILLINOIS 60604 PHONE) (312) 922-7435 CABLES) NORAMCO, CHICAGO December 9, 1965 Mr. O. W. Pfeifer Owens-Corning Fiberglas Corp. Technical Center Granville, Ohio Dear Mr. Pfeifer: Thank you for your letter of December 7, in which you raised several questions with reference to the Pallmann Mill. As we are not in position to answer these questions I am taking the liberty of passing a copy of your letter on to Dr. Gaze, in London, and I am sure the answers will be forthcoming promptly. I do know that Cape is using a Pallmann Mill to open Amosite Fibres, and this is done by the dry method. I am grateful for the fact that your people at Berlin are studying the possible substitution of Grade LD3 Amosite in view of the particularly tight supply of Grade W3 for 1966. In accordance with your note, I am arranging to send you, under separate cover, three pounds each of Grade LD3, Grade DX and Grade W3. I do not believe I previously sent you a sample of DX, but we did arrange to send a sample of this to Berlin along with the LD3. Grade DX is somewhat closer to W3 in fibre length than is LD3, and either LD3 or DX gradings are in better supply than W3. "Will write you again as soon as I hear from Dr. Gaze. Sincerely, NORTri AMERICAN ASBESTOS CORPORATION 01 040 1191 f. JL. i -- ;_ * w-- --ED_7* ~k \J^ 1 rO* 2 ' PFEIFER PL CC K V SMITH FG R J HCZVCY PL R 5 GRANT FG RE LONG FIBER ASBESTOS - I REPEAT BERLIN NOT ACCEPTING BCTTLZN ECKS and till on small scale basis attempt use of this fiber, we DO NOT, HOWEVER INTEND MAJOR CHANGOVER AND/OR MASS PURCHASING n K UNTIL RESULTS FROM TRIALS ARE EVALUATED. PLS BE ASSURED THAT THE BERLIN PLANT IS MOST-INTERESTED AMD HV DEMONSTRATED THIS ... ti.'-ii IN -- Vi-R In^j V I iVc XA^UC XfiCi/UC l S. V'LD U PREPARE. UR SPECIFIC IDEAS OF CORRECTIVE ACTION SHOULD DIFFICULTIES BE ENCOUNTERED THANK HARDWICK BERLIN ' 300 12/S CG lo/o5 -- z. Oo2 ww / v7 01 040 1192 J ' !,, tV' M D' IM nr MM *r.Or 1l jOlu> * sJ "C . A ?L TO ;3 :: HARDWICK BE . CC R S GRANT F3 H V SMITH FG ' XCC R` J MCEVOY PL W K SIDWELL NR HZ USE LDo AMGSITZ ASBESTOS... THERE ARE SEVERAL MAJOR ADVANTAGES ACCRUING TO UR OPERATION AND PRODUCT IF YOU CAN USE LONGER FIBER. AMCSITZ AND PARTICULARLY IF IT CAN BE MORE. EFFICIENTLY OPENED, OTHER THAN WITH THE WET PROCESS THRU THE BAUER MILL. IF U DC ENCOUNTER PLUGGING AND BALLING IN THE POURING NOZZLES THEN PERHAPS WE SHLD COLLECTIVELY GIVE YOU ASSISTANCE IN REDESIGN OF POURING NOZZLES AND SLURRY TRANSPORT, TO ELIMINATE BALLING OF LONG FIBER AMCSITZ PRIOR TO ENTRY TO NOZZLE AND ENTERTAIN IDEAS OF STRAIGHT PLANE INTRODUCTION OF SLURRY INTO POURING NOZZLE AS WELL AS MOLD. WE KNOW U HV A SMALL CLEARANCE DISTANCE BETWEEN'EDGE OF CORE AND SIDEWALL OF SHELL ON SMALL SIZES OF ONE INCH WALL THICKNESS. IMPROVEMENT HERE CAN BE INVESTIGATED AS WELL. AT THIS STAGE DO NOT BELIEVE WE SHLD ACCEPT ANY BOTTLENECKS OF PRESENT EQUIP AS BEING FINAL TO IMPROVEMENT TO END PRODUCT, SINCE MARKETING IS PLACING SO MUCK EMPHASIS ON FIRST.FOUR CATEGORIES OF THE NINE IMPROVEMENTS DESIRED 0 W P7Z17ZR 1125 12/3 MS 01 040 1193 //. ^ ~ T OI r\ EE TO PL > .J r o .1 3 ! * Or* *.* ."a1 v* iw --- fnt 4~ Wr* u Z unOnD^ jl CC R 5 GRANT PG H L HAYS FG .1 J MCEVCY ?L DORSEY MCRAE FG y X SISWELL FG H V SMITH FG THANKS FOR UR MEMO CF 12/5 CONCERNING LD-5 GRADE AMCSITE AS POSSIBLE SUBSTITUTE FOR W-3 WHICH IS IN SHORT SUPPLY. WE HV 500 LB SAMPLES BEING DELIVERED FOR TRIALS. OUR CONCERN AT THE MOMENT RELATES TO "PLUGGAGE & BALLING" OF BATCH IN POURING N0ZZL2 WITH FIBER LONGER THAN W-3 AS'WAS EXPERIENCED WITH HIGH PCT SUBSTITUTION OF "LOW COST" N-D ASBESTOS EARLY IN 65. UE WILL TRY HOWEVER AND APPRECIATE UR ATTENTION. KIKE HARDWICK' BERLIN 350 12/7 CG - -/ O CU/5C 0 rw..r\ r v 01 040 1194 Cwens-Corning FI BERG I. AS To:' - Berlin December 3 \'19651 From `0. IJ,' Pfeifer - Granville1' Subject LOEG FT.SRE AEQ3TTE - 153 *%*.v<>* *. * >V, r -y i t: : *r.< iV. Dear Mike: cc: Hr. R.S.Grant - Toledo, Mr. H.L.P-ays.- Toledo - Hr. R.J.i'cEvoy - Granville, Hr. Dorsey McRae Toledo .Mr. V.'.K.SidweH - Newark - *1 . '`vMr. H.V.Smith - Toledo,-vv % i'i 1 . -ip :1 We weretalking with Dob Cryor, o? NAAC in Chicago, a-few weeks ago and he .,, later covered us cn a. letter he wrote to Drosey McRae,- on a shortage of .hnosite >y ,-j-, * Gradings, in asbestos for 1966. 1 ,, * i * ^ H`^. Cryor wrote: "We still anticipate quite a little, difficulty in meeting-^your'V'-... '^'Z '.^.requirements' in the grades you prefer." ` i / . :. -iT'' i ,j: ^ "1 call to your attention a grade that has not heretofore-been. ,, v'Jk -.Hi f tried by your associates at the Berlin Plant. This is Grade LD3, which'is a. " grading - considerably longer in fiber length than Grade V.'3, which has -been core or less .standard with you for several years. Grade LD3 is normally priced `` considerably higher than T.y3 but in view of the shortage that we anticipate in **V'-v ..:f the medium-grades, wo are prepared to supply you Grade LD3 at the same price.. - GtaoAV5i , (Provided there would be no serious technical problems in'intro- V .f thelonger grading into, your operations, the LD3 wouid represent a very good valuevin terms of fiber for reinforcement. - , .vw? v-* v r ' , , c.,>7e were^discussing this situation with Dorsey the other day and we suggested f `7 that he- call you and have your permission to order 10 ton or so, for Plant ... trials. There may be LD3 in this country that Cryor can have shipped to you. * The-longer,LD3 fiber in pips insulation should increase the number of-drops in - the tests as.well as increase overall impact strength. When this fiber, is , . opened the longer length should be more advantageous yet. Even with the length-;1,/ attrition in tha wet Bauer Mill it should give better1 results than VJ3* -r"-Thisc ' / also would' be a distinct advantage .to. receive it at no price increase.5 *;-. ,-;r 1: ' > -...; ' - Several years ago, when Dr. Gaze of Cape Asbestos, Limited, was here from* V^'-V London,'. her,spoke of LD3 grade of amosite being used, in CAF05IL, where .unusual fv.' -.Vf \~i: ' high, flexural strength was obtained, which was attributed to the fullest _ - :!`v- 7 ; utilisation of long amosite fibers. When Karry Cohen, Managing Director of v.;< * . V ' if^so scheduled, using k'3 rather than LD3* Certainly..there shoti(ld.no^^^.,a^^-'f^ />_< fiber, on block, as might be exoected-with the'longw : H/-\: >? >---; -.rfl'7:*-' - 7/;; ifc-"':- yyw.:- MmaaastaausuuB/gssmw+rErix.'* r-rmw1.ALJu.'iugg^agww w 1 ... --*.bYy -r **j*:.- iT<l4.>* * 'u/ Ti<Ta*l-\T.?t f>V- -2.- * J*' Dsceinfcor 3 1965 "This could be* a lue'^y croak of having. this longer fiber fit into John Vyverberg's ."secure decisions $260- P? ton.'-ait probably is. v275 or $285 now. ; Getting'It Toe the-sane price. as W3 v; v.is a faydrabie cost break too. * . ' ' V. * ' /.jjt '.*! 'Z.272- *>-' " V . vb>" ' 11 b ' .''.t-V-We' are :sonding samples of LD3,ih case you do not havekthem, along witE V3 for;*~ vv'V'jfc \rf':*< length,'comparison ; k. : %. . -~Si . /* ^ ?C4- v ^` _ -:T*. .r.f * . .* . -V it;. . 1 . >W# ` '. ' ,f\ * S V*5 : >;Ltt'>-' '.*..' -. >. - ' *"*" ' v* *<* \ `bCWP/rsd.:,: ^ ' , S i- ' . . 1 - - -. &**$* v-'-b- r* K r#*-. . eifer- ' ^ if? ": t' .s,--.> ' -. ` .* ./; - -*&&;:. ..; : - H- v` - . ' ri1:. V '- 'V* <i . j5r;-jyK^>.;' 'V L^it.v 1 Sr , Z\pi. X: . . * . i-v-v-rr.' -jxy. . f-M. ` * ; *' i- o 0. Pfeifer - Granville Qner.inr Amosite Fibers seen: o' , --ye/*p- Dear Glenn: There is a piece cf ccui r.er.t for opening anosita asbestos fibers called a Pallr.'.an Mill, t is of English manufacture but there is an American distributer, na-ely, ''oilman Pulverisers Inc. 315 -'s'-' Art Street Hoboken, Hew Jersey Me would like for you to secure literature' regarding this mill and also arrange for one of their representatives to call on us, to discuss the efficiencies of this mill over their American competitor, Bauer Brothers, of Springfield, Ghio. Thanks for your help. OWP/md 0. H. Pfeifer 01 040 119? /$* BOARD OF TRAOE BUILDING, CHICAGO, ILLINOIS S0604 PHONEi (312) 922*7435 CABLES) NORAMCO, CHICAGO December 1, 1965 Mr. O. M. Pfeifer Owens-Corning Fiber glas - Technical Center Granville, Ohio Dear Mr. Pfeifer: s Further to your letter of November 10 and my letter of November 12, I now have had a letter back from Dr. Gaze in London in which he gives some information on the Pallmann Mill, which I know is used effectively in Europe for processing Amosite. I am enclosing herewith a copy of Dr. Gaze's letter to me, and a brochure on the Pallmann Mill, which explains the operation in some detail. After you have looked this over, if there is any additional information you would like us to try to obtain please let us know. With kind regards and best wishes. Sincerely, NORTH AMERICAN ASBESTOS CORPORATION end. 01 040 1198 ZL iJHiHj. \y O O \Z1 V LA"Vii v< i :I4 3 :I5 ?AaK STREET-LCNDCM ' 31. TElC^MOhC: CKC"vrNO 6C22 TGLCX N Z37SO. 17th November, 1965 N0v221S55 Dear 3ob, Thank you for writing to me on 11th November regarding Owens Corning and their interest in methods of opening Amosite. I well remember the visit you mention though I oonfess I have no reoollection of undertaking to provide Dr. Ealousek with this partioular information. We do agree that there should be more information available regarding the methods of treating our fibres and Dr. Hodgson is at present engaged on the first draft of a brochure on this very subject. So far as Kr. O.u. Ffeifer's problem is concerned, our experiments have clearly indicated that the Fallmann liill is tho best equipment available in Europe for opening Amosite of the type in which he i3 interested. The High Speed Cobra is also an excellent machine, and works on a very similar principle; this is used extensively iri South Africa and I only suggest that the Fallmann is the more interesting alternative since the High Speed Cobra is essentially a piece of South Afrioan equipment whereas Fallmann have agents and servioe in Europe and the United States. Their American address is : Fallmann Fulverizers Ino., 315 Hew Art Street, Hoboken, New Jersey. I am enclosing a brochure and would suggest that they are contaoted but if further information is required, I will ask hr. hoFarlane to write separately giving details of the speeds and adjustments which would be suitable for hr. Ffeifer's partioular application. Tours sincerely. _r. Cryor, North Amorloan, Asbestos Corporation, Chicago, Illinoio 60604. n. 040 1199 TURBO PULVERIZER SINGLE MOTOR TYPE PALLMANN - PULVERIZERS The economy of the PALLMANN Pulverizer - Single - Motor typeis proven in continuous oper ation owing to its sturdy con struction along simple lines. The grinding surfaces are of a high chrome vanadium - nickel steel construction. METHOD OF REDUCTION The method of reduction of the Pollmonn differs from those in common use. Material entering through the feed chute is thrown by on impeller rotating at high speed against the grinding liners of a chamber formed by two oposing cones The liners are divided into replaceable sections. There are three principles of reduction employed in a single, action dependent on selection of liner design: 1. Turbo (Jet) 2. Impact 3. Shear. The air suction in a second, collecting chamber located behind the grinding chamber draws the ground particles through an annular gap between the two chambers. Particle fineness is controlled by inserting confining rings of different sizes in the annular gap. The fineness of the material is determined by how long It remains in the grinding chamber before removal by air suction. The impel ler and a fan located behind the impeller on the shaft creole the high velocity of air. 01 040 1202 ftrt* ecvrurmit t*ceincfivH. The mills are heavily constructed and designed tor tough operations. The housing is a heavy, cast iron. The castings are properly aged before machining. The impeller and liners are a steel construction while the shafting is especially com pounded to withstand high torque. The pulverizer can be either V-belt or direct driven. Overdimensional bearings, low R.P.M. of the im peller compared to other high-speed pulverizers, and dynamic balancing contribute to trouble-free operation. The rtT"3Meff'Td210<3Ity to prevent dust ini'ffoaUction.  FEEDER Defending cn the nature of I he material, the pul verizer .s fed oy c viDratory, disc, or any mechani cal apparatus providing a uniform flow. A magnet should be placed m the feed chute to trap iron c- steel particles. WEAR The wearing points ore the fixed hammer o.ctes on the impeller end the grinding mors A com plete lopiacement of all the hommer pictos effected in ten minutes, resulting in savings tnrougn c minimum of downtime. A reason of the wicespreed use of the Pallmann Singie-Motor Pulveri zer -s the wear resistance of the .veer elements which make it capable of reducing economically materials which up to now couia be pjtvericcc: in high-speed miils only with excessive cores,on. tev#* i Jrj?& & Equipp;eTd .y'.iywiftitAr^..f'*s?e r-- Q CLEANING By the simple turn of two handwheels and removal of the impeller, the entire mill is accessible for cleaning. 2-2., The mills can be delivered with water-cooling jackets behind the cones, air-holes in the housing for additional air-cooling, or a system for blowing in warm air for drying material. Ail parts coming in contact with material can be mode of stciniess or an acid-resisting steel. The complete grinding system can be designed for hermetical enclosure for operation with insert gas, in which system we can supply an air-tight enclosed feeder. on THE GENERAL LINE OF PALLMANN GRINDERS Pallmann Mills ore available for coarse grinding, de-fiberizing, controlled granuicting pulverizing, emulsifying, or mixing of soft, brittle, tough, smear ing, hygroscopic, fibrous, fctty, heat-sensitive, and piasnc products. Wet operation is possioie with the Double-Rotating Mills, into which water can be added during grinding. 0 PRESENT APPLICATIONS The following medium-hard minerals can be reduced efficiently: raw gypsum, anhydrite, ben tonite, dry and wet clay, talc, medium-hard ores, graphite, mica, diatomaceous earth, fluorspar, chalk, barite, oil shale, shells, medium-hard lime stone, kaolin, asbestos. Coal-like products: coal, lignite, peat. Colors: organic and inorganic dyes and pigments, iron oxides, lead oxides, ochre. Pharmaceutical Products: drugs, leaves, ergot, china bark, maniok and other roots, bark. Grinding and mixing of salts and phosphates, such as: potash, fertilizer salts, raw phosphate, triple superphosphate, metasilicote and other alkalis, glauber's salt, sodium phosphates. Various Chemical Products: ammonium nitrate, aluminium sulfate, magnesium oxide, washing and detergent powders, soda, ammonium sulfate, so- Oil and fatty products: spices, fish and fishmeal, meats, soap fat, fresh animal bones, nuts, malt, olive pits, crackling, bone glue. Grain Milling Products: exra fine flour, fari naceous products, barley, wheat feeds, carob beans, hay, rice flour, potatoes, cocoa shells. Fibrous Materials: wood flour, chips for particle board, paper pulp, straw, bagasse, asbestos, chrome and tanned leather for synthetic leather manufac ture, cork granules and flour, textiles, board and paper woste, bamboo, hemp, reeds, tobocco stems, flocking chemical cellulose. Cocoa and Coffee: cocoa beans, cocoa presscakes, coffee. Plastic and elastomeric products: polyethylene, granules and scrap film, rigid and flexible P V C, styrene, nylon, foam rubber waste, record scrap, reinforced plastic waste, foam plastics. Natural resins and pitdi: colophonium, bitumen, /* 'mnrnn rrvnl tr%r hnrri oitch. ADVANTAGES OF PALLMANN 1. high output with less power 2. gritless product 3. easy cd|ustment of fineness without additional investment 4. wear-resistant grinding surfaces 5. no screen m mill 6. frequently no need for subsequent classification 7. grinding of different feeds up to fist size 8. ccn achieve narrow particle size distribution 9. easy substitution of wear parts with downtime minimized 10. low grinding temperature due to high volume of air 11. less tendency to smear 12. little space 13. moist and dry grinding 14. pulverizes heat-sensitive materials 15. a proven robust construction with air tight housing 16. no attrition pins 17. no tooth discs 18. no gear transmission Mills manufactured in five sizes according to rotor diameter: 18', 24", 32", 48" and doublechambered 48". Installation of mill on platform Installation of mill on floor For carrying out free tests, modern testing facilities are avail able. Based on years of experience in size-reduction and accessory field. Pallmonn lechnicans are able to discuss and handle many grinding problems. Complete installations are offered. PALLMANN PULVERIZERS LIMITED 59, Brompton Road, London, S.W.3. Telephone: KEN 8464 & KEN 8474 2-4 01 040 1206 Cables: ELDIMON, London *G / Hovember 10, 1965 r. E. 2. Cryor, Presideni; Uorth American Asbestos Corporation Board of Trade Building Chicago d, Illinois Bear Mr. Cryor: I an now located au the Technical Cantor, at Granville, Ohio, and am in need of soma information on your products, which you can readily supply. Would you please send me data, on your various grades of amosite asbestos, on fiber lengths and percentages of the sane in the various grades that va use, as wall as others you have. Would also like to have the chemical analysis as veil. Several yoars ago, Dr. Gage of Cape Asbestos Ltd. called at the Technical Center and talked udth Dr. Halousek, who is no longer with us. He, Dr. Gage, promised to send cravings and details of their equipment for fiberizing amosite asbestos, vhon he returned to England. He vas accompanied by your Hr. Jerome. Perhaps this fiberizing equipment information is available fr cm your offico. Ho also recommended our use of your LD-3 grade of fiber . 'a never did receive the information, that is to the best of our kr.cvl edge. We have searched the files here to no avail. Wo hopo-you can giro us tho above information ve are seeking. Thank you for your kind service. We appreciate your help. Wo vould be glad to see you again. Yours very truly, CW?/md 0. W. Pfeifer, Manager High Temperature Produces 01 040 1207 OCT 12 1961 aTG-GGHiiJrrc x.* Ili'EZGLAS co^pchat^on INTRA-COMPANY CORRESPONDENCE 7ECHNCAL CENTE?. -- GHANViLLE, OHIO ATTENTION! OF :!r. 7. F- Shannon October 10, 1951 i:3GM EUSJSCT G, L. iCalousak CALL R31PORT - i!OR??I AlFICAi: AVTATIOW CORF. V. 33. Case - CranvlUn A. C. Siefert - Granville 0. W. Pfeifer - Toledo B. Boyd - itoieco V/. E. Sidwell - Toledo R. C. Aiaoe - Berlin D.v._ G.*ge or' Cape AsVesfccs Ltd., suppliers of amosite asbestos through FAAC for ICayic, came to Gramrlie to discuss our problems with and needs for, aaosite. ilr- Jerome of ILIAC accompanied kin. Dr. Gage has been closely associated with development of Capcsii, i. hydrous calcium silicate, nearly the same as ihernobestos, manufactured in Inland. his company, in developing Caposil, made a study of various methods of opening wsosite fiber. 'hey found the Dauer mil], very destructive to fiber length. In fact any .rough vet handling of anosite causes rapid fiber length breakdown. Dr. C-age strongly urged, that if ve ere to obtain optimum perforaancc from amosite fibers, to stop use of Bauer milling, and Uydropulping in handling . the fiber. He rcco;~.ended the, fiber be opened dry and added os tiio last ingredient to the slurry and then mined ju3t long enough in a paddle type or ripooa type mixer to disperse it. Pumping is also destructive and the hoyno pula? is recommended for landling Kaylo slurries. hue same recommendations were made ".o rroGuciion t.y Rescarcu. 'liiese are the basis for the Sprout Waldron experiment;)! trials at Btrlin. , Dr. G;:ge upon his return to Sigicnd' will forward complete drawings, and . details, of their equipment for fiberiging Amo3ite. Caposil contains 18 amesite and is formed by pressure filtration similarity es Theruobectos. Ibis product at 11 pcf density exhibits the amazing flexural strength of 250 psi. 'the high strength i:; not-attributed so much to the molding' process as to the fullest utilization-of long amosite-fibers. The LD-3 grade (i;.26g/T compared to r,2C3/e for W-3) in used. According to Gage, Caposil is resistant to impact breakage. Cape j isbestos also produces a higli temperature insulation, Capos ite, which is similar to Unibestos. Their total high temperature insulation sales are ; close to :;if:,GCO,GGG/year. Capon ite is being replaced by. Caposil and it is planned to go over completely to the iiydrous calcium silicate insulation. C^-LKiaa TAji-4 ' l.YSAR ...... 6 MONTHS ......... DESreOY NOSV......... Asaw^^isa? 040 1208 ( use to 1200 F. The pneumatic I system consists of roof mounted 42" dia. steep cone collectors with flanged inlet and outlet air connec tions and an 18" inside dia. dis charge at the base of the cone, and No. 3 PHLM fan direct connected to a 10 hp, 1800 rpm standard open-type motor. A simple manu- SPROUT-WALDRON EQUIPMENT USED BY EHRET MAGNESIA MANUFACTURING COMPANY TO PRODUCE QUALITY INSULATION The concept of using carbonate of magnesia reinforced with asbes tos fiber as an insulating material dates back to the 18S0's and the commercial manufacture of the material by Ehrct Magnesia Manu facturing Company has a history covering more than half a century. But something new has certainly been addedl The big difference in the process at Ehret and that employed by most magnesia insulation manufac turers is the use of a traveling robot, called a "Weigh Larry." Carrying two conical hoppers and equipped with blinking lights, rheostat adjustments, indicating devices and a variety of pushbut tons and control instruments, this compact pneumatic and electric brain operates the production cycle with amazing precision. The Lar ry carries its own air compressors pressure tank, and two conical hop pers. It moves from station to sta tion, taking an accurately weighed charge from the mixers, filling the preheaters, which in turn automat ically fill the molding machines. The Sprout-Waldron contribu tion to this modern magnesia in sulation manufacturing system in cludes a 24" single runner heavy duty swing-head attrition mill and s'* . a pneumatic system for handling the fiberized asbestos. The mill operates intermittently on a 24- Thit S-W Belt Conveyor feeds into a Sprout-Waldron Single Runner Attrition Mill hour day, seven day a week sched ule producing a batch every three- quarters of an hour. It is equipped with anti-friction bearings, adjust able runner head for coarse and fine grinding, spike tooth manga nese steel shredding plates and a shaft mounted 30 hp, 1600 rpm open frame motor. Both African and Canadian as bestos fibers are fed into the mill by means-of a Sprout-Waldron Sprout-Waldron producti collecting fan picks up fiberized asbeilot from attrition mill and conveys it to either of two process lines. 14"x30' belt conveyor driven by ally operated diverter in the line a Reeves Vari-Speed drive with a between the fan and the cyclones 1 hp, 1800 rpm motor. Here the or cone collectors determines the fiber bundles are opened and the system into which the milled as individual fiber strands fluffed and bestos is fed. separated so as to provide greater The adjustable runner head de structural support and reinforce vice on the attrition mill is used to ment to the magnesia insulation. advantage when changing from Fiberized asbestos is picked up one type of insulation to another. by Sprout-Waldron products col When the high temperature insula lecting system and conveyed into tion material is being prepared, the either of two different process attrition mill is used in relatively streams, depending on whether wide open position because the Thermalite (853! magnesia insula fiberizing is followed by violent tion) or Thermasil (calcium sili mixing in a hydrapulper and rib cate insulation) is being produced. bon mixer. Closer plate adjust The former is the most common ment is used on the 85? magnesia and is utilized for temperatures in insulation because the process in ^507the range of 600* F. The calcium volves relatively mild mixing in silicate insulation is suitable foQ J ^0"! 209 i NORTH AMERICAN ACBESTOS CORPORATION BOARD OF TRADE BUILDING, CHICAGO. ILLINOIS 0604 PHONE: (312) 922-743S . CABLES: NORAMCO, CHICAGO November 12, 1965 Mr, O. M. Pfeifer Owens Corning Fiberglas Technical Center Granville, Ohio Dear Mr. Pfeifer: It was pleasant to have a chance to talk with you again on the telephone yesterday, and while I do not at this moment have the letter you sent me, I am taking steps to ask Dr. Gaze in London to give us up-to-date information on the Pallman Mill, and other types of opening equipment for both wet and dry opening. I expect I will have something I can pass on to you in about ten days time. You also indicated you were interested in chamical analysis of the various types of asbestos, and I think the best I can do is to refer you to the Asbestos Textile Handbook (copy enclosed), which gives this information on Page 7. You were interested too in information on the fibre length of the various gradings of Amosite, and in the same book on Page 22 a range of the approximate length of the unmilled Amosite fibres is shown. Another indication of fibre length is in the comparison of Canadian Box Test values. As you know the Canadian Box Test method consists of shaking sixteen ounces of asbestos through three screens into a pan. The first screen is 1/2" mesh, the second screen is 1/4" mesh, the third screen is 10 mesh per inch, and anything that goes through the third screen is caught in the pan. Comparative Canadian Box Test values for the various grades of Amosite are shown below: Amosite Grade LD-3 D-3 DX MD 15-1/2 12-1/2 14-1/2 11-1/2 0 2-1/2 1/2 1-1/2 1/2 1 1/2 2 0 0 1/2 1 continued 01 040 1210 Mr. O. M. Pfeifer November 12, 1965 2- K-3 W-3 SW GW GK S-33 13 6-1/2 0 0 0 1 1-1/2 1-1/2 - - 1-1/2 44 12 2-1/2 12 2 10 3 1/2 1/2 1-1/2 1-1/2 2 3 Trusting you will find this information of some value in your work, and' looking forward to the possibility of visiting you before too long. Sincerely yours, NORTH AMERICAN ASBESTOS CORPORATION RECryor/jc end. oi 040 mi <* EOARD OF TRADE SUl'-DING, CHICAGO, ILU 3034 PHONE: (312) 922-7435 CABLES: NORAMCO. CHICAGO i.O^C 19*75 --` nonS wOming r xocrglno OlwLkO X i x^CCir .*r l -vcicrriiin to our coizvcrjo.ti-jr.3 earlier ihij wee:;, on t:;c. J'.ibjcci of Antosiic gradings, we s.iii anticipate c eiie a little di_i:eui..y in meeting your requirements in. the grades you prefer. In this connection, I cc.il to your attention a grade that has not heretofore been tried by your associates at merlin plant. This it Grade GGG, K which is a grading considerably longer in fibre length than Grade V/d, v/incn lias bciTi i..orc or icoo `wix.ii von lor :cvcrii vcaro. oracc zs nor::.car/ oricc-c coaoiccraozy aa^nor man .. .101 m view oi b.;c jO ut..C-L i*c w*<ici in i.\c cv..iu*:`; '-rm^; `..o c.:4c pro* wO ws*.:r:iy yoi: - m i.;j :i*<,c 'hrice no 0*11:' . 1* --ro vide cl there would oe no serious technical problems in introducing tno longer grading Into your operations, the Lho would rep-Cocnt a very' ^00c* v'u.u: in icrmo 01 *101*0 .11* rciaiorcoi;.o*iz. -Inclosed herewith -are small tam.ties of both Ldt and V.'s .or visual otsainiunclsn, and if your Gorlin slant could test and evaluate tnis grading v/c would be glad to send you surniclent material for slant test. 01 040 1212 Lcr.g f.bcr amosiie is used princ ,e manufacture o; c: .1 in- Dcpcsiis located in Transvaal Province, Union of South Africa, provide tire only commercial source of amesire r.bcr. Approximately 57,000 short tons were produced there in 1957'. Anthophyilite: Essentially a silicate of magnesium and iron, usually with a small amount of aluminum, anthophyilite belongs to the group of orthor hombic amphioolcs. Its chemical formula may be expressed as (Fc.Mg)7 SisO;2(OH)2. The fibers of anthophyilite are usually brittle and lacking in tensile strength and arc therefore not suitable for textiles. Tremoiitc and Actinolite: These monoclinic amphiooles are least im portant of the commercially used varieties of asbestos. Tremolite--CAoMg-SihO-j-.. (OH) >--is a calcium-magnesium silicate whose fibers arc often long and silky but generally too brittle and of inadequate tensile strength for use in the fabrication of textiles. It is of value prin cipally for nitration purposes because of its freedom from iron and its resistance to attack by acids. Most of the tremoiitc fiber produced comes from deposits located in northern Italy. Actinolite--(Ca.Mg.Fc),-,Sis022 (OH)2--is similar in composition to trem oiitc exempt for the presence of iron which replaces some of the mag nesium. Like tremoiitc, the f.bers are too weak and brittle for spinning bur have good resistance to acids. Its practical value is limited and produc tion is small. TABLE A--CHEMICAL COMPOSITION OF VARIOUS TYPES OF AS3EST05* CllRVSOTILE SiOs ........... MiO ........... FeO ........ FcjOj ......... A:ao*......... K;0 ............. CaO ............. Xa-0 ........... 37-44% 39-44% 0.04.07* 0.1-5.0% 0A-lj% 12.0-15.0% Tr.4.0% -- CnocmouTE | Amosite A.NTHOPHYLUTE Trexoute 4943% 0-3% 13-20% 17-20% 2.5-4.57* - 4.0-8.5% -- 49*53% ! 1-7% 34-44% 2.97* 2-5% --- - 0.5.2-3% 56-58% 28-34% 3-12% 0.3-1.5% 1.04.0% -- -- 51-62% 0-30% 144.0% 1.0-4.07* 0-5.07* 0-18% 0-9% -- 'Encyclopedia of Chemical Technology, Yol. 2--Anthrone (0 Carbon Copyright 1948. Interscience Publisher, New York and London. 7 01 040 1213 c Amositc: For the same reason as stated under "Crocidoiitc" above, amositc is aiso supplied in a semi-miiled condition and classified on the basis of length of fiber in the scams or unmillcd cobs from which the various graces are obtained. Control of quality is aiso achieved bv comparison with stand ard or "umpire" samples, supplied at regular intervals from the mills. Fibers from the various mining properties in the Transvaal are graded as shown below: Grade D3 LD3 Oil OX MD M :<3 tt'3 5X $Y/ 52 CX 07/ S3 ; Approx. Lencth Range of Unbilled Fider 2" to 6" ` 2" to 6" 1" to 2" : r to 2" ; v-i* to 2" ! %' to 2" \ Vi" to 2" Vi" to 2" 3/16" to 1" | 3/16" to 1" 3/16" to r to vi" ?i .0 *7S' tt ,'0, T>/J* H 1 Designation Long Lon; (part Sberixed) Medium Long Medium Long Medium >Xrecii.ura Medium Short Medium Short Shorts Shorts Shorts Shorts (part Sberiied) Shorts tpart r.berized) Shorts (part aberited) j ' 1 ! i ! Color Gray Gray Gray Gray Grav Gray Gray Gray Gray Gray Gray Gray Gray Gray m 01 040 1214 it SECTION - 2- ASBESTOS THE RAW MATER/A 01 040 1215 SECTION 2 -- ASBESTOS, THE RAW MATERIAL Page 2 -- The last paragraph and the last sentence discloses that amosite asbestos is used in Cape Asbestos "Caposil" the 1400 calcium silicate, which is 200 higher than our Kaylo at 1200 F and only 400 F below Kaylo 20 products. The Cape's Caposil has a higher maximum temperature than any of the U.S. manufactured high temperature insulations, with the exception of Carey Temp claimed at 1600 F, which is not a calcium silicate^ and Unibestos at 1600 F, which is not a calcium silicate either. Page 3 -- The last paragraph gives the origin of the name "Crocididolite" coming from the Greek meaning 'wooly stone1. "Chrysotile" stems from the Greek also, meaning 'fine hair of gold'. Page 5 - - The last paragraph here states the fineness of asbestos fibers, which are in the same millionths of an inch diameters as are Fiberglas filaments. Pages 7 and 8 -- Here is described the difference between amphibole and chrysotile asbestos. The former fibers are solid throughout, while the chrysotile fibers are believed to be hollow. Page 14 - - The grades of amosite asbestos are here listed at their mines of origin. Page 24 - - "AW" amosite is described as a blend of fibers in a more opened condition than the other grades and is a processed, semi-shor,tr.~ grade. -iSp; Page 26 - - Under "Amosite" are listed the various products of "Caposil". The 1800 Fhigh temperature insulation is not a calcium silicate and is not made in pipe diameters. It is made in a plastic, hard setting cement as well. 01 040 1216 NORTH AMERICAN ASBESTOS CORPORATION U. S. Subaldlary, Tha Cap* Aibtstos Company Umlttd, London BOARD OF TRADE BUILDING, CHICAGO, ILLINOIS 60604 PHONE: (312) 922-7435 CABLES: NORAMCO, CHICAGO September 22, 1966 Mr. O. W. Pfeifer Owens-Corning Fiberglas Corp. Technical Center Granville, Ohio Dear Mr. Pfeifer, Thank you for your letter of September 19, addressed to Mr. '"'I Cryor. In accordance with your request we are enclosing the following literature: "Asbestos The Raw Material" \ ^Asbestos Reinforced Plastic Pipe" "Asbestos Reinforced Plastics ^Resist Heat & Chemicals " "The Use of Crocidolite Asbestos in Reinforced Plastics" ' Very truly yours, NORTH AMERICAN ASBESTOS CORPORATION JCanzoneri/ encl. Oi 040 1217 040 1218 2 The myth Asbestos in history i \ 1 The Emperor Charlemagne Marco Polo -Archeological studies have shown that as to protect them from the all-consuming used for acoustic insulation even then. early as 2500 years before recorded time heat of the funeral pyre and so preserve Down the centuries references are found people in Finland knew how to add fine the ashes. in chronicles and proceedings of learned asbestos fibre to the raw material to Linum vivum (living linen) they called it. societies which indicate that the `magic strengthen the sides of lightly fired pottery. In 1702 a funeral urn was found near the mineral' was neverforgotten. For example, When the material had been strengthened, Naevian Gate at Rome containing a skull, the Emperor Charlemagne, who lived in the sides of the vessels could be made calcined bones and ashes wrapped in a the 9th century, is alleged to have saved a thinner to produce cooking utensils long piece of asbestos cloth. It can be desperate situation by throwing his table which were not only lighter in weight but seen, with its contents, in the Vatican cloth into the fire and recovering it un in which food could be cooked more Museum today. A Greek doctor called harmed. His enemy bowed in deference to quickly. In 438 BC Plutarch recorded that Anaxilaus who was banished by the the possessor of obviously supernatural '1 the Vestal Virgins who tended the ever* Roman Emperor Augustus in 28 BC for powers. The cloth was undoubtedly made burning fire of the sacred royal hearth held practising magic wrote: `if a tree is sur of woven asbestos. 1 'perpetual lamps' with wicks of a woven rounded with linen made of (asbestos) the In the Middle Ages the Venetian explorer material which was almost certainly noise of the blows given by the axe will Marco Polo described how in Siberia in asbestos mixed with vegetable yarn. be deadened thereby, and the tree may 1250 he was shown a piece of unburnable The ancient Romans who found asbestos be cut down without being heard. For cloth made, they said, from the skin of 'i in the Italian Alps regarded it as a vegetable these qualities it is that this linen occu the salamander which lived in fire. His and worked it up into cremation cloths, in pies the very highest rank among all enquiries led him to asbestos mines which which they wrappedthe bodies of theirkings the kinds that are known.' It was being were probably those known to have been i i i i i1 fi i *;Ji v\ A fragment of prehistoric Finnish pottery An ISth century drawing of asbestos. Plate 32- Volume V 'Fossils' of the collection of Natural History drawings which form part of the Royal Collection in the library of Windsor Castle, reproduced here by gracious permission of HM the Queen tU v 3 i Kr f i\ - i * operating in the Russia of Peter the Great. and though there are deposits of Blue | In the 15th century we hear of asbestos cloth being used for armour in battle. A asbestos (Crocidolite) in Australia, South . Africa, where it was first discovered, is still j contemporary rhyming account of the siege its main source for commercial purposes. I of Rouen (1420) talks about: the chief of which is in the manufacture of The Kyngis herauldis and pursuiauntis In cotis of armys amyauntis asbestos-cement products. But as with the discovery of White as bestos in Canada, so with Blue in South 1 In 1671 there appeared in a magazine Africa. The discovery was merely noted, called Journal de Letterati, published in and no attempt was made to explore its Venice, an account of 'a Substance found possibilities until 1891, when Francis Oats, in great quantities in Some Mines of Italy a director of De Beers Consolidated Mines !! - out of which is made a kind of incombus Ltd, who controlled the diamond mines of f tible Skin, Paper and Candle Week.' A South Africa, formed a group of his I certain Signor Castagna who had come associates into the Cape Mineral Syndicate upon this asbestos could treat it so that it to exploit it. Oats' attention had been . resembled lambskin dressed white. 'Of the same matter this Artist hath wrought a called to the Blue asbestos at Prieska by a , speculator called Cohen, to whom speci Week (Wick), never to be consumed as mens of the rock had been brought by long as 'tis fed, nor altering its quality after some African 'boys' working at the Kim the aliment is wasted away. And if that berley diamond mines who had their home I famous and incombustible Oyl were found at Prieska. I- out again, we read of, this matter would Two years later Oats was persuaded to ' yield the Week for that everlasting Light so broaden the activities of the Cape Mineral much celebrated by the Antients.' But of course it wasn't everlasting, someone was Syndicate and establish a company in London which would undertake manufac always topping it up. ture as well as mining. The name given to It was only by the end of the 17th century that asbestos began to be regarded as something other than an object of super stition and curiosity. Asbestos came into its own with the discovery of the deposits in Canada in the middle of the 19th cen tury, with the accent perhaps on the con servation of heat by 'lagging' rather than resistance to fire. When the price of coal began to increase, 'thermal insulation' gradually developed into the science it is today. Sir William Logan, the first Director of this company, which was incorporated on December28,1893, wasTheCape Asbestos Company Limited. In 1925 the company acquired a number of mines in the Transvaal of the kind of fawn-coloured asbestos, first discovered in 1907, known as Amosite. This had long, stiff, rigid fibres, and while unsuitable for easy spinning and weaving proved itself ideal for use in insulating materials. Today it is used in the Group's 'Caposite,' 'Asbestolux' and 'Marinite' products, and in 'Caposil 1400' calcium silicate materials. ' ! Geological Survey in Canada, 'noted' asbestos as early as 1847. In 1876 it was rediscovered by Joseph Fecteau, and two years later the mining of the principal de posits at Thetford, Quebec, had become a going concern. The asbestos Sir William Logan noted was White (Chrysotile) asbestos, as in deed was every deposit discovered up to that time. The Italian amianthus used by the ancients was White, and the asbestos in the Russian, Chinese, Indian and Cypriot mines was White. Some time between 1803 and 1806, how ever, many years before Sir William Logan's findings in Canada, Mr H. Lichtenstein, a German geologist, was travelling near Prieska in the Orange River Valley in South Africa where he came upon a mass of \ heavy asbestos which was lavender blue t- * in colour. This was something quite new 01 040 1220 [ '* .d*V. '1 ; < . - -. .5, -... -- ------ " - ./ T . ` - . y"j' ' ' *' . V - ` >; ' ? *$"***: Asbestos the word The mineral has been known in England by two names-first amianthus or amiantus, and later asbestos. Amianthus is the Greek Amiantos, A is the negative and miaino means to paint over something with another colour, to stain or dye it, and thus to defile, soil, taint, pollute, corrupt it, make it impure. The adjective amianto was applied to this undefilable mineral, for on being thrown into the fire it was not only not consumed by it or diminished by it, but seemed positively to be purified by it Pliny report^ that after the stains were burnt out, a piece of asbestos cloth `came out of the flames whiter and cleaner that it could possibly have been rendered by the aid of water.' Such words were doubtless based on observation, but he was guessing when he went on to say that the natural colour of the mineral was red, only becoming white through the agency of fire, and that it grew in the deserts of India scorched by the burning rays of the sun. `Here, where no rain is ever known to fall,' he writes, `and amid multitudes of deadly serpents, it be comes habituated to resist the action of fire.' It is very rare, and those who find it sell it at prices equal to those given for the finest pearls. Moreover `it effectually counteracts all noxious spells, those wrought by magicians in particular.' Apart from all this, the realisation that it was not affected by fire led to the belief that it did in fact ignite and. once ignited, went on burning for ever without being consumed. In this respect the word amiantos was probably also applied to a mineral which wasn't asbestos at all but s `fabulous stone'which was reputed to burn with an unquenchable flame and was more likely to have been unslaked lime. However that may be, this second attribute gave the mineral its other name. Asbestos is another Greek word. A is the negative again, and sbestos is the adjective from the verb sbennumi meaning to quench, die down, dry up, extinguish. Asbestos is the inextinguishable material, the mineral which once it starts burning never goes out. It has thus acquired a name which contradicts its essential characteristic, which is that it does not burn. The mineral was called undefilable and inextinguishable, but never what one would have expected, incombustible. Amiantos came into the English language as ami anthus and survived till the beginning of the 20th century, when it gave way to asbestos. In the early 19th century both words were used in England, though it is likely amianthus was reserved for the silkier, softer types. The poet Robert Southey (1774-1843) used both words in The Young Dragon, which he wrote about 1815: With amianth he lined the nest An incombustible asbest Asbestos is the word used in North America and in North European languages (German: asbest). But amiantos has held its ground in the southern Latin languages: amiante in French, amianto in Italian, amianto In Spanish. Marco Polo found the mineral being called salamander; in Germany it has been known as Stone Flax (steinflachs), and French-Canadian miners have called it Cotton Stone (p/erre-a-cofon). One type of asbestos has been called by a Greek word .. which means Woolly Stone (eroc/dof/fe), another type by a Greek word meaning Fine Hair of Gold (chrysolite). 01 040 122 The Cape Asbestos Company Limited was formed in London in 1893 to undertake the mining of asbestos in South Africa and the manufacture from it of thermal insulation materials (lagging) in Italy. Since then it has expanded into a Group of associated companies manufacturing not only insulation materials from asbestos but also of mineral wool, as well as a range of asbestos-based brake linings. Production of raw asbestos fibre from its own mines is still a basic activity of the Group, and is the subject of the present booklet. Two types of asbestos are mined -known as Blue asbestos and Amositewhich have unique qualities differentiating them from the great bulk of asbestos produced elsewhere (mostly in Canada, Russia and Rhodesia). The company's development has been based on making the most effective use of these special qualities. In 1961 the responsibility for advising on negotiations and sale of all crude and pro cessed fibres produced from our mines was delegated to a wholly owned sub sidiary company with head office in Lon don created for the purpose. Cape Asbes tos Fibres Limited. The Group's mines are based on two main centres in the Cape Province and in the north-eastern Transvaal, where small settlements have been built up entirely by the company, housing and providing for a population of some 900 Europeans and upwards of 9000 Africans. The manufactured products of the Group cover a wide range, including Caposite asbestos, Caposil HT and 1400 calcium silicate, Noramite plastics reinforcement felts and dough moulding compounds, Rocksil and Rocksil-K rockwool, thermal insulation materials; Asbestolux asbestos board products; Marinite asbestos sheet; Don and Capasco automotive and indus trial friction materials. 6 The natural fibre that will not burn Asbestos has the exceptional property of being a natural fibre that will not burn. Fibres are the essential building materials of'nature, but fibres of the vegetable and animal kingdoms will all burn more or less freely. Asbestos, the fibre of the mineral kingdom, stands apart: it is non-combustible. Before it is mined, asbestos is a rock - as solid and dense as granite or marble. It is found in seams or layers between greater thicknesses of rock of almost identical composition. The asbestos rock breaks down to fibres when it is milled, but the accompanying rock becomes powder. The reason for the existence of the seams of asbestos is not completely known, but they are of entirely mineral origin. They are not caused by the decay of vegetable deposits like coal. The great value of asbestos is its fibrous nature. Very fine fibres can be obtained by rubbing the surfaceof asbestos rock. Each fibre pulled away is seen to be composed of more fibres, and these in turn can be further subdivided. The most powerful optical microscopes cannot pick out the smallest fibres; these are between one millionth and one ten-millionth of an inch in diameter. The average thickness of the fibres used in our factories is about ten times this size, but even so some hundreds could lie side by side in the thickness of this paper. A piece of crude asbestos as big as the top of a finger yields many thousand millions of fibres, which would s tretch round the world if placed end to end. `It is found in teams or layers between greater thicknesses of rock of almost identical composition' - the rock face at one of our Amostte mines `The asbestos rock easily breaks down to fibres' 01 040 1223 7 'Each fibre pulled away it teen to be composed ol more fibres.* Amosite team in our Penge mine 01 040 1224 i; Mineralogical classification of asbestos (calcium magnesium iron silicate) and Anthophyllite (magnesium silicate), but these are only of limited commercial importance to the asbestos industry. Group II Chrysotile or White asbestos This is the fibrous variety of Serpentine, a magnesium silicate mineral having the chemical formula Mg.fSi.O.oKOH),. It is produced from extensive deposits in Canada, Russia, Rhodesia, and to a smaller degree in the Transvaal, Australia and elsewhere. Any naturally occurring mineral which may be manipulated or processed into fibres may be called asbestos, but there are'a number of different types that are quite distinct mineralogically, although they may conveniently be classified in two groups: Group I Amphibole asbestos The Amphibole group of minerals con tains many varieties, including five which are fibrous. These are complex silicates having the general chemical formula MiSiaOittOH),, M representing calcium, magnesium, sodium or iron in various proportions. The fibrous amphiboles con tain double chains of silica tetrahedra and this arrangement gives enormous strength along the chains and in the fibres; the bond between adjacent chains is very much weaker, and for this reason the fibrous amphiboles may be easily broken down to give strong fine fibres. Thetwo important varieties of Amphibole asbestos are: Crocidolite or Blue asbestos and Amosite Both are iron silicates - Crocidolite a sodium ferroso-ferric silicate; Amosite a ferrous magnesium silicate. Crocidolite is found mainly in South Africa, but also m Australia and Bolivia. Amosite is found exclusively in South Africa. Other fibrous amphiboles are Tremolite (calcium magnesium silicate), Actinolite Difference between Amphibole and Chrysotile Scientists have shown that there is a fundamental difference m structure be tween the fibres of Chrysotile asbestos on one hand and of Amphibole asbestos on the other. The finest Chrysotile fibres are believed to be hollow, whereas the ultimate Amphibole asbestos fibres are solid throughout. This explains why Amosite and Blue asbestos fibres are hard and springy and why White asbestos fibres From pieces of White (top). Amosite (centre) and Blue (bottom) asbestos rock of equal weight come piles of fibre of unequal volume. These photographs illustrate how the stiff resilient nature of Amphibole (Blue and Amosite) fibres give them considerably more bulk than White asbestos fibres 01 040 1225  soli, flexible and absorbent. As shown ine electron micrographs, Amphibole es are larger in diameter. The finest -its asbestos fibres are usually in the ;ion of 0 02 micronsin diameter, whereas e finest Am pm bole fib res are in the region 0T microns in diameter. When sepaled by fiberising processes, Blue or mosite fibres will produce a great floccunt volume: this consists very largely of nil air which is held in minute cells by the caflolding of fine resilient fibres. On the mer hand, the soft flexible fibres of the Chrysotile variety are particularly suitable for use in asbestos cloth, engine packings, gaskets and like products. The length of Amphibole asbestos de pends upon the grade, but. in general, Amphibole fibres are considerably longer than White asbestos fibres of similar price or grade. The additional length and the stiff resilient nature of the fibres means that a given weight of Amphibole asbestos will fiberise to a much greater volume than the same weight of White asbestos. Customers who are used to purchasing White asbestos will notice that they receive their raw Blue or Amosite in a less finely milled condition than Chrysotile. Our asbestos is despatched in this relatively crude or unfiberised form from our mines deliberately in order to reduce shipping costs. If Blue or Amosite was milled at the mine to the same extent as White, the volume produced would be so great that the cost of transport would be inflated out of all proportion. Photograph of schematic representation of the structure of Chrysotile asbestos 3Mg02Si0,2H,0 The molecules are fitted together to form a tuOular structure. The diameter of the smallest tubes is less than one ten-millionth of an inch Photograph of schematic representation of the structure of Amphibole asbestos Crocidolite- Blue asbestos Na,03Fe0Fe,0s8Si0aH>0 Amosite asbestos 1 5Mg05-5Fe08Si0,H,0 The molecules are fitted together to form straight, narrow strips. The smallest fibres are a few millionths of an inch in width and may contain as many as a hundred of these strips 01 040 1226 10 Photograph* ol Chrysotile and Amphibole asbestos fibres magnified 40,000 times on an electron microscope They show th.it Cbiysome .White) asbestos torms very fine, iioi.ow <'.bres. whereas Amphibole (A.nosite and Blue asbestos) consists ol long, solid ano ngid fibres Resistance to heat Amovto .ind Blue asbestos hhres discolour And lose strength, ns a result ol oxidation, when they sire heated at temperatures above 480 F. Textile and flocculcnt products made from these fibres alone, such as yarn ,mci cloth, packings, mattresses, rooe lagging ano loose fill, should not be used abovethis temnerature. Butoroducts ncorooratmg Amosite or Blue asbestos with stable inorganic hinders or fillers may be used safely at much highpr temperatures. The re sistance of such products is not adversely affected by the discoloration ol Amosite due to oxidation, and any loss in fibre strength will not affect t*e integrity of the products within the limiting temoerature ranges normally claimed for the various heat insulating materials. CotOUf Average tensile strength Resistance to chemicals Typical chemical analysis Silica Alumina Ferrous oxide Ferric oxide Manganous oxide Calcium oxide Magnesium oxide Sodium oxide Potassium oxide Carbon dioxide Water of crystallisation SiO> AI,Os FeO FeI0> MnO CaO MgO NeiO K.O CO> H,0 01 040 1227 CHRYSOTILE (White) CROCIDOLITE (Blue) AMOSITE , Matt White Lavender blue, varying somewhat with slight changes in chemical composition associated with different mining areas. Varies from almost white to yellowish* brown, according to small changes in iron content. 400000 Ib/sq in 500000 Ib/sq in. The strongest of all natural fibres, its basic tensile strength being one and a half times that of steel piano wire. 300000 Ib/sq in. Virtually no resistance to acids, which dissolve the magnesia component of the mineral. Good resistance to alkalis, neutral salts and organic solvents. : ' Outstanding in its resistance to acids. Good resistance to alkalis, neutral salts and organic solvents. - V* _-V r . ;.. Good resistance to acids, but not as good ^ r' as Crocidollte. Good resistance to alkalis, neutral salts and organic solvents. ,: 39-8 3-3 ` 1-1 0-8 . 0-1 ' 1-6 " 39-5 r` 0-1 , - 0-1 ... 1-0 . te-e! i % 51-4 20-3 17-5 0-1 0-8 1-4 6-2 0-4 1-9 100-0 % 49-3 40-9 0-4 0-7 0-4 5-7 ...... 0-2 ~ 0-3 0-2 1-9 ;; \ *ioo4> - s.i 'CT ; . ,:-.v ' \ >** . . . At.-v-v -.sir- , t - r'y_- 13 Our asbestos mines We operate Amosite and Blue asbestos mines in South Africa at the places shown on the map. -Extensive deposits.of Amosite and Blue asbestos occur in the banded ironstones of the Cape Province and the Transvaal. The asbestos was originally mined from the surface where the seams emerge, but our mines now penetrate many hundreds of feet into the rock where fresh asbestos of excellent quality is obtained. Unlike the deep deposits of White asbestos that occur in serpentine, Amosite and Blue asbestos occur in relatively narrow strata extending over great areas of South Africa. The deposits do not usually persist in great depth, and for this reason variations of properties exist in fibres mined in different areas. This en ables us to supply a range of fibres having individual characteristics which may be used to the maximum advantage in particular processes. The crude ore is brought to the surface and purified by processes that have been developed and perfected over many years in the asbestos mining industry. Our mining activities in South Africa are controlled by Cape Asbestos South Africa (Pty) Limited, through its subsidiaries Cape Blue Mines (Pty)Limited and Consolidated Blue Asbestos Corporation Limited, on the production of Blue (Crocidolite) asbes tos; and Egnep (Pty) Limited, with its wholly owned subsidiary company, Amosa (Pty) Limited, which produce Amosite asbestos. BLUE ASBESTOS As already mentioned, in 1890 the Cape Mineral Syndicate was formed and ac quired mining rights over certain farms in the Prieska and Hay districts of the Cape Colony. The Cape Asbestos Company was formed in 1893 to take over these rights from the syndicate, and in 1948 Cape Blue Mines (Pty) Limited purchased all the assets and mining rights of The Cape Asbestos Company's Blue Croci dolite mining activities. Cape Blue Mine* (Pty) Limited Cape Blue Mines operates Blue asbestos mines and plants at Koegas/Westerberg in the North-Eastern Cape; the Pomfret Mine in the Vryburg District of the Cape Province, and the Malipsdrift Mine in the Pietersburg District of the Transvaal. Koegas and Westerberg Mines Situated on the north and south banks respectively of the Orange River some 46 miles downstream from Prieska, the two mines being connected by the Riley Bridge, constructed in 1951. In this area the company owns, in addition, large tracts of asbestos-beari ng ground, on which several small mines have in the past yielded quantities of Blue asbestos and are awaiting further exploration. Burlington House, Rissik Street, Johannesburg, where Cape Asbestos South Africa (Pty) Limited have their offices mm m !ii:iiiSE!ll! c! ! lr!l!KI!!lill!IE29I. El ! i::K!l!!Ki;g!l ffi The grades of Blue asbestos produced at the Koegas/Westerberg mines are: S Medium grade H Medium/short grade WDS Short grade A, B, C Machine-treated long grades Pomfret Mine Situated some 134 miles north-west of Vryburg in the Northern Cape, near the Bechuanaland border and the edge of the Kalahari Desert. The farm Pomfret, where the mine is established, is one of the farms in this area over which Cape Blue Mines (Pty) Limited holds the asbestos mining rights, the total area of these farms being 59,000 morgen (about 125,000 acres). The grades produced at Pomfret are: S (medium grade) and A, B, C (machinetreated long grades). Special hand-cobbed grades are also available for specific requirements. Consolidated Blue Asbestos Corporation (Pty) Limited The share capital of this company was purchased in July, 1958. The company owns a mine on the farm Warrendale, 8 miles from Silverstreams station on the Kimberley-Postmasburg branch railway line. Please fold out map on page 19 Kokerboom (quiver tree) with a distant view of one of our mines across the river v 01 040*1230 /i .w 16 AMOSITE ASBESTOS Egnep (Pty) Limited and Amosa (Pty) Limited These companies were registered in 1916 to acquire leases of {he mineral rights over the farms Penge and Streatham on the banks of the Olifants River in the native area of Sekhukhuneland in the Lydenburg district of the Eastern Transvaal. The mining camp at Penge is 65 miles from Lydenburg, the then railhead. Later the railway line was extended to Steelpoort, bringing the railway station at Burgersfort on the Lydenburg-Steelpoort line to within 22 miles of the mine. These companies were purchased by The Cape Asbestos Company Limited in 1925, by which time the mining leases had bfcen extended over the farms Havercroft, Riverside, Weltevreden, Zamenloop and Kromellenboog. In 1927 Egnep (Pty) Limited purchased the assets of Malipsdrift Asbestos Company, which held 943 mining claims in the Pietersburg area, and in 1958 the 186 adjoining mining claims of Uitkyk asbestos were purchased. The farms Havercroft, Streatham, Penge, Riverside, Weltevreden, Zamenloop and Kromellenboog cover an area of approxi mately 25,000 morgen (53,000 acres) bounded on the north by the Olifants River and on the east by the Steelpoort River. Four separate mines are in production on these farms. The Amosite asbestos ore from the mines on Streatham and Penge is treated in plants on the farm Penge, the grades produced being: 03, LD3 Extra long fibre DX, Oil Long fibre M, MO Medium long fibre S2 Medium short fibre S33 Short fibre The mine at Weltevreden. has its own treatment plant, and the grades produced are: W3 Medium fibre SW Medium short fibre GW Short fibre At Kromellenboog the treatment plant produces: K3 Medium fibre SK Medium short fibre GK Short fibre RK Short fibre BLUE AND AMOSITE In the Malipsdrift area Blue asbestos is mined for Cape Blue Mines (Pty) Limited and Amosite for Egnep (Pty) Limited. The Blue production is blended to produce Standard Transvaal S, while the Amosite grades are blended with production from other mining areas to produce opened fibres against specific demand. The feed end of one of the amosite mills at Penge ----- Q-1--0 4 0 -12 33 17 It 1 The broken asbeitoi-bearing rock-ten parts oi asbestos to a hundred parts oi rock-is brought to the surface by diesel train I j Batch sampling of bagged fibre for quality control plus visual assessment of fibre quality and uniformity being carried out under European supervision after milling ------- orwrOT 01 040 1230 A view ol the Penge mine from the Burgerslort Road against the backcloth of the bush-covered Drakensourg 19 Headgear of the Keep Shaft at Penge, the depth of which is 1438 ft Oust collection units at one of the new amosite mills st Penge 01 040 1237 24 Uses for Blue asbestos and Amosite Commercial applications In the preceding pages we have pointed out the distinctive properties of Blue asbestos and Amosite. These properties lead to distinct and specialised uses-Blue and Amosite have never been regarded as substitutes for White. In the following pages we discuss some of the wide range of commercial applications for Blue asbestos and Amosite either alone or blended with White asbestos. PACKINGS Blue asbestos, long fibred grades (or plaited packings. Blue asbestos, medium and short grades (or Blue asbestos millboard. Packings woven from Blue asbestos yarns are used for glands and stuffing boxes in chemical plants, particularly where re sistance to acids is required. The pack ings are plaited in the usual way, graphite or grease being incorporated as required. Polytetrafluorethylene covers or sleeves may be used in conjunction with Blue asbestos packings if extreme conditions of acidity are involved. Millboard prepared from short Blue asbestos is also used as a packing or gasket material on chemical plant where acid resistance is particularly required. YARNS AND CLOTHS Blue asbestos, long fibred grades Yarns and cloths woven from long Blue asbestos fibres are strong and have high chemical resistance. Typical uses for Blue asbestos cloth are: Filtration cloths Diaphragms in electrolytic cells Curtains, forming dampers in fume exhausts Smoke chutes Heat insulation in mattress covers for use on railway locomotives and in acidcontaining atmospheres generally. REINFORCED PLASTICS Blue asbestos, long fibred grades (or (alts. Amosite asbestos, extra tong grades for felts. Blue asbestos, medium and short grades for dough moulding compounds. The elastic modulus of Blue asbestos is over twice that of glass fibre. Felts pre pared from long Blue and/or Amosite asbestos are being developed for use with epoxy, polyester and phenolic resins, particularly for applications where great stiffness or chemical resistance is needed. The adhesion of plastics to asbestos is superior to that of glass, and this increases the chemical and water resistance. Shorter Blue asbestos fibres may be used in 'premix' or 'dough' moulding com positions to confer dimensional stability and water or chemical resistance, together with good dielectric properties. FELTS Blue asbestos, long fibred grades Amosite asbestos, long fibred grades Felts from long fibred Blue and Amosite asbestos for a wide range of reinforcing, roofing and insulation compounds; with bitumen or other waterproof impregnation for weather and corrosion resistant applications. 01 040 1238. 25 HEAT INSULATION Ampnibole asbestos is particularly suit able for use in heat-msulating materials. It is in tins field that the long fibred Amosite is esoecially useful. There are two reasons for this: firstly because the long, resilient fibres form a large volume, enclosing a high proportion of still air which confers good heat insulation; and second, because Amosite provides ex cellent reinforcement in magnesia or calcium silicate and, more important, enabling the slurries from which these materials are prepared to be filtered rapidly. Details of the use of Amosite and Blue asbestos in various products for heat insulation are given below. Amosite rope lagging Amosite grade D3 Long fibred Amosite is particularly suitable for use in rope lagging. The long fibres lend themselves for use in simple carding machines in which the fibres are rolled and twisted together to form a rope that may subsequently be covered in a braiding made from an asbestos or glass yarn. The high bulk volume of this asbestos gives a rope that is very light in weight and having better heat insulating value than ropes made from the softer White asbestos. Preformed asbestos blocks and pipe sections Amosite long and medium long grades 'Asbestos' blocks and pipe sections for use in heat insulation are best made from Amosite. These materials have been used for many years on oil refineries, generating stations and in all conventional heat insulating applications against hot surfaces at temperatures up to 12001 F. One of the particular features of this material is in its fibrous, resilient nature. This means that it may be transported over great distances with less risk of breakage than is usually encountered with light weight materials. Preformed magnesia or calcium silicate blocks and pipe sections Amosite long and medium grades Experience has shown that Amosite is the best reinforcing fibre to use in these products. The function of the fibre is to provide reinforcement and resistance against im pact, heat stress and accidental damage. Between fifteen and twenty per cent of Amosite, fiberised in such a way as to retain a good proportion of coarse, crude bundles, is usually employed. A particular virtue of Amosite in these processes is that the long resilient fibres keep the wet slurry 'free' and 'open,' thus enabling it to be filtered quickly and cleanly. Blocks and pipe sections for use against higher temperatures are usually denser and contain high proportions of diatomaceous earth or calcined magnesia. These are usually made by the same processes and, for the same reason as given above, Amosite fibres are incorpora ted with advantage. Loose rill Blue asbestos or Amosite medium long and short grades. Use longer fibres if greater bulk is required. Well-fiberised Blue asbestos and Amosite may be used for loose fill insulation and as the filling in heat insulating mattresses, particularlywheresomemeasure of chemi cal resistance is required. 01 040 1239 JUU 26 Insulating compositions Amosite medium long grades for insulating compositions Amosite short grades for finishing and self-setting compositions Amosite is a very convenient fibre to use in heat insulating compositions, its long, stiff fibres ensure that a good bulk is obtained and also provide the necessary reinforcement. Mixtures of between twenty and fifty per cent of well-fiberised, long Amosite with magnesium carbonate or a good grade of diatomaceous earth will give a composition having good thermal insulating properties. Up to ten per cent of clay may also be added to give some 'slip' and 'bind.' For finishing compositions, up to ten per cent of well-fiberised Amosite may be used with cheap fillers such as chalk or sand; again, add up to ten per cent of clay to give 'slip' and 'bind.' k._ Self-setting compositions are prepared from cement containing between ten and thirty per cent of well-fiberised, short Amosite. ASBESTOS SPRAY Blue asbestos and Amosite medium and short grades Short, well-fiberised Amosite or Blue asbestos is the best fibre to use in asbestos spray. Asbestos spray has been extensively developed as a heat insulating, acoustic, and anti-condensation medium. The fibres are usually sprayed in a fine mist of water, and a soluble adhesive is sometimes added to the water. When dry, the sprayed asbestos will have a density of 9-13lb/cu ft (depending upon the conditions), at which its thermal conductivity will be in the region of 0-32 Btu/sq ft/hr/(cF/in). BITUMEN AND PITCH MOULDING COMPOUNDS Blue asbestos and Amosite medium and short grades Mouldings for use in conjunction with water and chemicals have for many years been prepared from mixtures of bitumen or pitch with blue asbestos. Amosite asbestos may also be used. It is usual to employ a short, well-opened Blue asbestos or Amosite for this purpose and to mix it hot with bitumen or pitch, then to press it in water-cooled moulds or to extrude or otherwise form it into pipes. A particular use for Blue asbestos in this connection is in bitumen composition battery boxes. Both Amosite and Blue fibres strongly resist the acid content of all types of bitumen and are therefore suitable for the production of pitch fibre pipes. They can also be considered for special road surfacing applications. 'Dagenite' battery boxes being made from a Blue asbestos-bitumen composition at Pritchett and Gold's works, Dagenham ASBESTOS-CEMENT AND OTHER BUILDING BOARDS Asbestos-cement sheets Blue asbestos and Amosite medium and short grades Blue asbestos and Amosite are, with great advantage, added to the fibrous component for the production of asbestoscement sheets. The unique filtration properties of Amosite and Blue asbestos are well known to manufacturers; both types of fibre disperse Chrysotile in the slurry, because of their resilience. Besides giving this greater dispersion of fibre and in creased surface contact with the cement. Blue and Amosite increase the slurry bulk and can thus give greater laminate thick ness when required. Up to forty per cent of the fibrous component may usefully consist of Blue asbestos and/or Amosite in flat or corrugated sheet manufacture. 01 040 t240 27 Lightweight asbestos insulating boards Amosite asbestos medium and short grades Lightweight asbestos insulation boards may be prepared on the same type of machine using between twenty-five and thirty-five per cent of Amosite blended with lime and diatomaceous earth. After forming the sheets in the usual way, a calcium silicate bond is formed in highpressure steam. Hydraulic cement may also be used as the binding medium in this process. Asbestos-cement pressure pipes ~Blue asbestos and Amosite medium and short grades The factors that have been outlined re garding the use of Blue asbestcs and Amosite for asbestos-cement sheet apply to an even greater degree to the manufac ture of asbestos-cement pressure pipes, where a high rate of production is required together with a strong product. In such processes it is usual to apply pressure to the surface of the pipe as it builds up on the machine by means of a blanket roll or a rubber roll. It is essential that the mix does not squeeze out or move as a result of this pressure, and the fast drying properties conferred by the use of Blue asbestos in particular are of great value in this respect. Depending upon the type of process employed, between twenty and fifty per cent of the fibrous content of the mix may usefully be Blue asbestos or Amosite. Johns-Manville asbestos-cement pipes of the type in which our Cape Blue asbestos fibre is used Preparation and fiberisation As has been explained, it is customary to supply Blue asbestcs and Amosite in a relatively 'crude' form in order to save transport costs. It is therefore usually necessary to open the asbestos further before using it in the various processes that have been described. For textile processes, the same opening machinery as is used for White asbestos is employed. For heat insulating products it is usually desirable to open the asbestos as much as is reasonably possible, and high-speed hammer or attrition mills are recommended. (For reinforcement of magnesia insulation and like products, a less severe opening is recommended.) For use in asbestos-cement products and other board-making processes the best filtration properties are obtained from relatively coarse fibres, and it is therefore advisable not to open the fibres any more than is necessary to produce a smooth, uniform sheet or pipe. Slow-speed mills or kollergangs as are conventionally used for White asbestos may be used for Blue asbestos and Amosite. but the hard, springy fibres may be damaged by excessive heavy milling, and this treatment should be kept to a minimum. If wet milling is preferred, approximately thirty per cent of water should be added to the fibre in the mill. If this type of opening is used, it is often preferable to introduce the Blue and/or Amosite last so that the Chrysotile can act as a cushion against any grinding effect of the opening process. Processed asbestos fibres Apart from producing raw asbestos from our mines and selling it in that form throughout the world, we also meet the demands of customers who require their fibre already processed; and our factories at home and overseas are equipped with the latest machinery for processing and preparing all types of asbestos fibres, Amosite, Blue and White asbestos for all trades and uses. Our experience in this field is at the disposal of all actual or potential users of asbestos. Types, blends, lengths, and degrees of opening can be varied to suit customers' requirements. We shall be glad to give advice on the selection, preparation and blending of asbestos for use with cements and bitumi nous products for building materials, roofing compounds, plastic and electrical mouldings, etc. Specially prepared fibres are available as a heat insulation medium either alone or as the binder for various types of plastic non-conducting materials. Our processed Blue asbestos fibres are widely used for loose-fill acid packing or insulation, filtration of liquids or gases, absorption and mechanical reinforcing; our Amosite processed fibres for many varied types of insulation products, ab sorption and mechanical reinforcing. Mixing fibres will inevitably, by attrition, assist the opening process and may con sequently result in loss in fibre strength. Processed fibres plent 01 040 1241 fc&r* lumlongwM|t| >p(iw!l(ctJ*'>.?5;W ? SM nmt^ijitute'bAyprbclod^f . .. fWS^,j^;Bra<Bncv.o|vn `*t'^iaJU^j^reirt#' flctflarlfhard, rulIIwitdMiret f r.'I'Vw < , fcwo#S&&birtj>iwir*k` jU(iil&^imrttatiofi'1 ' " '"%#? ' tmifebdr^ ftf.rA >iji*dhiiidSjipii (n| ii.t&avfeslctancd &ib*l 01 040 1242 Appendix Ordering information Cape Asbestos Fibres Limited in London acts as the commercial office for all raw asbestos produced by the Cape Group of Companies, and all enquiries should be sent to 114 Park Street, London W1. Orders arising from these enquiries, however, are placed by the buyer with the mining company concerned. Orders for materials produced in South Africa are accepted for payment in South African currency. By special arrangement however, Cape Asbestos Fibres Limited will accept orders on behalf of the mining companies, in which case payment is made in London in sterling. All grades of asbestos except for pro* cessed fibres supplied by our United King dom manufacturing companies are sold in short tons of 20001b net (20201b gross), normally packed 20 bags to the short ton, each 100 lb net (101 lb gross). BLUE ASBESTOS is supplied f.o.b.* African port, bags included, by:Cape Blue Mines (Pty) Limited, who operate the mining companies within the Group pro ducing Blue asbestos. Payment terms: net cash by irrevocable letter of credit opened in their favour negotiable with and confirmed by Barclays Bank DCO, Rissik Street South Branch, Johannesburg; alternatively an approved London bank for orders accepted by Cape Asbestos Fibres Limited. AMOSITE is supplied f.o.b.* African port, bags extra by Egnep (Pty) Limited, who operate the mining companies within the Group producing Amosite. Payment terms: net cash by irrevocable letter of credit opened in their favour negotiable with and confirmed by the Standard Bank of South Africa Limited, Rissik Street South Branch, Johannes burg; alternatively an approved London bank for orders accepted by Cape Asbes tos Fibres Limited. PROCESSED FIBRES produced by our South African manufacturing company, Cape Asbestos insulations (Pty) Limited, at Benoni, Johannesburg, and other as sociated companies in the Union, for direct shipment from South Africa, are supplied f.o.b.* African port, bags in cluded, by Cape Asbestos South Africa (Pty) Limited. Payment terms are net cash by irrevo cable letter of credit opened in their favour negotiable with and confirmed by Barclays Bank OCO, Rissik Street South Branch, Johannesburg; alternatively an approved London bank for orders accepted by Cape Asbestos Fibres Limited. Processed fibres produced by our United Kingdom factories and subsidiaries for delivery within the U.K. and overseas are supplied f.o.b. United Kingdom ports or delivered within the U.K. by Cape Insulation and Asbestos Products Limited. These materials are packed in standard bags each 112 lb and/or 56 lb net; alter natively 50 kilos and/or 25 kilos net. ANNUAL CONTRACT To assist in economic mining program ming and to avoid disappointment to end users, Blue asbestos and Amosite asbes tos for direct shipment from South Africa are generally sold on an annual contract basis, the annual contract period being from January 1 to December 31 each year, the contracts being negotiated in the October of the previous year. * At customers' request freight will be prepaid and charged at cost insurance covered and premiums debited at cost 01 040 1243 30 Blue asbestos and Amosite products of the Cape Asbestos Group of Companies and of overseas associates BLUE ASBESTOS PLUTO Blue asbestos mattresses by Capamianto SpA, Italy Cape Asbestos Insulations (Pty) Limited. South Africa PLUTO Blue asbestos cloth by Cape insulation and Asbestos Products Limited (at Acre Mill, Yorkshire) Capamianto SpA, Italy Cape Asbestos Insulations (Pty) Limited, South Africa PLUTO Blue asbestos millboard by Cape Insulation and Asbestos Products Limited (at Barking Works, Essex) Capamianto SpA, Italy Cape Asbestos Insulations (Pty) Limited, South Africa PLUTO Blue asbestos fibre filled rope lagging by Cape Insulation and Asbestos Products Limited (at Acre Mill, Yorkshire) Capamianto SpA, Italy Cape Asbestos Insulations (Pty) Limited, South Africa AMOSITE CAPOSITE preformed moulded insulation materials by Cape Insulation and Asbestos Products Limited (at Barking Works, Essex; Acre Mill, Yorkshire) Caposite Insulations Limited, Canada Cape Asbestos Insulations (Pty) Limited, South Africa James Hardie and Company (Pty) Limited, Australia Isolamiante SA France (as 'Isolamiante') Capamianto SpA, Italy J. de Boer and Company, Holland Eduardo Rosa, Spain Montisol Argentina SRL, Argentina Nippon Asbestos Company, Japan Pittsburg Corning Corporation, U S A (as 'Unibestos') CAPOSll 1800 high temperature block insulation by Cape Insulation and Asbestos Products Limited (at Barking Works, Essex) Capamianto SpA, Italy Cape Asbestos Insulations (Pty) Limited, South Africa CAPOSITE and CAPOSIL plastic compositions, hard setting cements and insulating concretes by Cape Insulation and Asbestos Products Limited (at Kentmere, Westmorland) Capamianto SpA, Italy Cape Asbestos Insulations (Pty) Limited, South Africa CAPOSITE pure asbestos fibre filled lagging by Cape Insulation and Asbestos Products Limited (at Acre Mill, Yorksmre) Capamianto SpA, Italy Cape Asbestos Insulations (Pty) Limited. South Africa CAPOSIL 1400 calcium silicate preformed insulation by Cape Insulation and Asbestos Products Limited (at Barking Works, Essex) ASBESTOLUX asbestos board products by Cape Building Products Limited (at Cowley Bridge Works, Uxbridge, Middlesex) DanskEternitFabrik A/S, Denmark James Hardie and Company (Pty) Limited, Australia MARINITE asbestos sheet (by arrangement with Johns-Manville International) by Marinite Limited (at Germiston Works, Glasgow) 01 040 1244 Basic research on blue asbestos. A micro-fibre of blue asbestos mounted in a machine for determining tensile strength Aopiied research on blue asbestos. Investigating a biend of asbestos fibres in a small-scale board-making machine 01 040 1245 4^v?: .., .. / . t"**"tr'tfK'` -i ." *'./<v > " " ' ' '- ' /' *. ' -"'*'. ' ssl& **'' '- J-- : -'.. . V1 ' ..^''^''v * .-; ' - ** v?-..'- 'c*'-**';.'.i : ,./ - ;;* : :,' . ,t - '''<?--' '- :Vi`- :: ''*.; -: ' '-i r ': :? ^fec-.-y - - '/ '-*"*}*& -" v ' *-> - . V- --*vV' -:s-~>A-l.-'-'' -'^* -'. ' ;; _ .:*v V>."<_ : / -,v - ' c V r-r% ' V*-. - ' * . : ifeisv >/' >;, *-V. -t . .^ fg:|* *yf_ :? ;i:\ p's ; f- ti Jill Iff#*:1 ';V.V, :*` VrJH;' : '-' *>.v.>'..*' *'' '`--s -n. .- -T* -;:A-. fA\v.:-fe-v--V'e`-` -'' --'f-:* *1 .*..iV7-.:-*;'*..; */ ; '->,* r':? .^fc. v- ' ;;:< ' ..i,. r.- . .>;1 J;;>:-v'^ 'i -/J .;.- ;*,; 5iv; :vr . * - Vi^' . - . .-A` , .:< . 01 040 1246 3 TEST METHODS FOR BLUE fc AMOSITE ASBESTOS FIBRES 01 040 1247 SECTION 3 -- TEST METHODS FOR BLUE AND AMOSITE FIBRES Under "Contents" are listed six (6) Sections, which are self-explanatory as they are studied. These six sections are divided in information as follows Section 1 -- Length Tests Section 2 -- Measurement of Degree of Openness Section 3 -- Cleanliness Section 4 -- Asbestos-Cement Fibre Tests Section 5 -- Chemical Tests Section 9 -- General Information 01 040 1248 Test Methods for Blue and Amosite Asbestos Fibres Cape Asbestos Fibres Limited 114 Park Street London 01 040 1249 Contents O Section 1 LENGTH TESTS 1*1 Quebec standard asbestos testing machine 1 *2 Bauer McNett Fibre classifier.* 1 *3 Length sorting of asbestos textile fibres 1 *4 Rotap dry sieve test Section 2 MEASUREMENT OF DEGREE OF OPENNESS 2*0 Measurement of degree of openness 2*1 Blaine Dyckerhoff air permeability tester 2*2 Alternative cells 2*3 Rigden air permeability tester 2*4 Interpretation of results Section 3 CLEANLINESS 3*1 Grit and dust contents 3*2 Colour Section 4 ASBESTOS-CEMENT FIBRE TESTS 4*1 Wet volume and filtration tests 4*2 Measurement of reinforcing value Section 5 CHEMICAL TESTS 5*1 Moisture and ignition loss 5*2 Acid loss and extractable materials Section 9 GENERAL INFORMATION oi 040 1250 9*1 A laboratory for fibre testing 9*2 Suppliers of asbestos testing apparatus Page *1 1/1 1<2/1 1*3/1 1*4/1 2*0 2*1/1 2*2/1 2*3/1 2*4/1 3*1/1 3*2/1 4*1 /I 4*2/1 5*1 /I 5*2/1 9*1/1 9*2/1 The testing of Asbestos Fibres By far the majority of the world's asbestos production is of chrysotile (white) asbestos and testing methods for asbestos have been generally associated with the qualities and characteristics of this type of fibre. The most authoritative information we have seen covering asbestos fibre testing is undoubtedly the Manual of Testing Procedures prepared jointly by the Asbestos Textile Institute, the Asbestos Cement Products Association and the Quebec Mining Association. This book does, however, clearly specify as its objective the testing of chrysotile fibres. The different physical and chemical characteristics of the amphibole types of asbestos call for the development of other testing procedures and/or modification of the testing methods applied to chrysotile asbestos. Our many friends who use asbestos have frequently asked how the blue and amosite fibres in which we specialise should be tested and how they should equip their laboratories to establish a practicable system of quality control. With this in mind, we have endeavoured to summarise our own technical experience Of this rather specialised problem and this manual of test methods is the result The Cape Asbestos Group of Companies is the world's biggest producer of crocidolite (blue) asbestos and is responsible for the majority of the world's production of amosite. Its experience of production of amphibole fibres extends over more than 70 years and throughout this time these fibres and chrysotile fibres have been used in developing a wide range of products by the manufacturing companies within the Group. The use of amphibole fibres in the manufacture of other products outside the Group's manufacturing range has been pioneered and fostered by The Cape Asbestos Company in association with manufacturers; the development of asbestos-cement pressure pipes in Italy in the 1920's is a good example of this co-operation. It is in the spirit of co-operation with chrysotile producers in the interest of asbestos users that this manual has been prepared by the Laboratory staff of Cape Asbestos Fibres Limited. It assumes that, as the greater part of production of amphibole asbestos is used in conjunction with and support of chrysotile, chrysotile testing methods should be applied to amosite and blue asbestos as far as possible. Specific tests for the asbestos-cement industry include a method for the measure ment of reinforcing value of asbestos fibre in asbestos-cement boards, using a simple air-curing technique, and wet bulk volume and filtration tests for asbestoscement slurries. The latter two tests depart from recognised methods as, by making these tests on suitably diluted asbestos-cement slurries, important differences in the bulking, dispersing and filtration properties of the different types of asbestos are brought out. We are grateful to our friends in the asbestos industry and to equipment suppliers for their help in compiling this manual. We have taken information from many and varied sources. It is impossible to list them all but our sincere appreciation is freely extended to ail technicians who have been responsible for working out sound testing procedures for asbestos fibres. The continuous development of knowledge and interest in these types of fibre call for constant re-examination and adaptation of testing methods. This manual is printed in loose leaf form t6 accommodate additional or replacement pages which will be issued as necessary, to ensure that it is kept as up to date as possible. Cape Asbestos Fibres Limited 114 Park Street London W1 01 040 1251 01 040 1252 Quebec Standard Asbestos Testing Machine 11 Equipment 1 The Quebec Standard Asbestos Testing Machine (or Canadian Box Tester) consists of a nest of three testing boxes, a pan and a cover, clamped to a shaking table. The base of each testing box consists of a brass screen, the mesh specification of each screen being as follows: Box Number Screen Opening Diameter of Wire 1 (Top) 2 3 4(Pan) 0.500' 0.187' 0.053' aluminum sheet base 0.105' 0.063' (4 mesh) 0.047' (10 mesh) These are US Standard Sieves, or Tyler equivalents. The shaking table is driven by an eccentric having throw and 1-fe' travel, the speed of rotation being 327 rpm. A timing device governs the motor so that the eccentric makes exactly 600 revolutions in each test and then automatically stops. Complete details of this machine are given in publication NRC 3470 of the National Research Council of Canada, entitled `Specifications and Drawings for Quebec Standard Asbestos Testing Machine, Model No 2.1938*. The essential features of the machine, derived from these drawings, are shown diagrammatically on page 1T /3. It is particularly important that the direction of rotation of the eccentric is counter-clockwise, when the machine is viewed from the side shown in the diagram. 2 A balance with a capacity of at least 1 lb and a sensitivity of 0.1 oz will be required. The scale should preferably show both pounds and ounces and kilogrammes and grammes. The balance should be equipped with a large scoop. Method 16 oz or 454 gm of asbestos are placed in No 1 box, which is then covered and clamped. The machine is started and at the end of the timed test the contents of each box are weighed. Reeults The results of the Quebec Standard Test are usually expressed in ounces weight of thefibre on each box; alternatively they may be expressed as percentages: Box 1 234 Ounces abed %-- ------ The total is always 16 oz and the results may be expressed to 0.1 oz. 01 040 1253 Interpretation of The Quebec Standard Test was developed as a primary method for classifying Results chrysotile asbestos fibres. Canadian producers provide a minimum shipping specification for run-of-mill chrysotiles by means of this test. The machine is entirely suitable for chrysotile fibres, but the same cannot be said for amosite and blue asbestos fibres. For this reason producers of amosite and blue asbestos do not quote the Quebec Standard Test for purposes of specification, though at the same time the results of this test may be taken as a guide to the grading of these fibres. The disadvantage of the box test becomes apparent when it is applied to processed types of amosite and blue asbestos and, to a lesser extent, to processed chrysotiles. In the milled state these fibres produce a bulky flock, the greater part of which will remain on the first tray of the box tester, although in the non-processed state a large proportion may pass through the first tray. Any results obtained in the box test therefore should be interpreted with due regard to the degree of openness of the fibre (see Section 2). The general rule here is that the higher the degree of openness for any grade of amosite or blue asbestos, the greater the proportion of fibre retained by the first tray; a limit to this rule is reached when the fibre has been excessively shortened by progressive milling. Because of the bulky nature of milled amosite and blue fibres, it is often impractical to use the full 16 oz of fibre for this test The fibre as such will pack the top box and little or no agitation of the mass will take place, with the result that no proper separation occurs. It is therefore recommended that a sample of 100 gm be taken for such fibres, the result of the test being expressed directly as a percentage. 01 040 1254 Main shaft revolving at 327 r.p.m. 43' ctrs Quebec standard asbestos testing machine 01 040 125 1 3 i' ctrs Bauer McNett Fibre Classifier 1-2 The Bauer McNett Fibre Classifier determines the length distribution and fines content of medium and short grades of asbestos by a wet classification method. A sample of fibre is washed over a series of four screens of diminishing aperture, and the material collected at each screen is dried and weighed. Five such fractions are determined. The action of the Classifier is such that in each of its four tanks the fibre, dispersed in a large volume of water, passes through the gap between a vertical screen and baffle plate parallel to the screen (see pages 1 -2/4, 1 -2/5). The fibre thus lays parallel to the plane of the screen, while at the same time the water flows through the screen. Fibres of length greater than the average mesh size of each particular screen are retained by that screen and smaller fibres passthrough. It is important that the agitator speed and direction of rotation should be correct so that the classifier functions properly. Agitator Speed 540 40 rpm Agitator rotation clockwise when viewed from top. Equipment 1 The Bauer McNett Fibre Classifier No 203A. The essential details of this machine are shown in the diagram on page 1 -2/5, and the design of the vacuum cups used when draining the tanks is shown on page 1 -2/6. These cups are not supplied with the machine and require to be built separately. 2 a Balance, sensitivity 0.01 gm b Drying Oven, operational temperature 105C c Filter papers 18.5 cm diameter, Whatman No 541 Sample weights Type of Fibre Screen sizes and Times Screen Sizes (Tyler Mesh) Sample Weight in grams Duration ofTest in minutes amosite and blue asbestos, groups 2 to 7 4,14,35,100 10 20 chrysotiles, groups 3 to 6 and - 7D 4,14,35,200 10 20 Method With screens and tank stoppers in place, fill the tanks with water. Adjust the flow so that there is slight overflow from the constant head tank and start the motor to set the agitators in motion. Stir the 10 gm sample of fibre into 500 ml water in a beaker and pour the suspension into No 1 tank. Record the time. While the classifier is running the tanks should be watched, should they tend to overflow. An overflow will be caused by accumulation of the bulk of the sample on one particular screen, and if this occurs the screen must be cleaned in situ, either by brushing it with a long handled brush, spraying with the small hose pipe used in the final operation, or simply agitating the water between the baffle plate and screen with a suitable rod. The latter method is probably the more preferable, but in any event care must be taken that this cleaning process does not cause fibre to pass end on through the screen while the machine is operating. 01 040 1256 Meanwhile, fit one 18.5 cm filter into each filter cup and clamp the cups in place. When the classifier has run for 20 minutes, shut the water off and stop the motor. Withdraw the stoppers from the tanks and allow the contents to drain through the filter cups. Connect the nipple at the bottom of each filter cup to a water vacuum pump to speed up drainage. As each tank empties, wash down the screen and the interior of the tank with a small hose pipe, ensuring that all fibre has been washed through to the filter cup. After completely draining the cups, take out the filter papers carrying the fibre fractions. Fold each filter paper and place them in the drying oven for a minimum of two hours. Weighing the Fractions The type of analytical filter paper recommended is of constant weight within 0.10 gm. Weigh each fraction therefore with its filter paper, and subtract the weight of the filter paper to find the weight of the fraction. (The average tare weight of the filter papers should be predetermined on batches of 20 or more.) Results Determine the percentage of fibre collected on each screen. Subtract the total percentage of the four screens from %100 to find the percentage of fibre passing through the fourth screen. Express the results as follows: McNett Classification +4M -r14M t35M -^100M -- 100M %a b c d e I nterpretation of Many types of chrysotile fibres contain a proportion of extremely finely divided Results serpentinous matter. The assessment of this fine material is done on the Bauer NcMett classifier by accounting for ail the fines which pass the 200M screen. The 4M --14M --35M --200M screen sequence is not necessary when testing amphibole fibres and therefore a 100M screen may be used in place of the 200M. (It may be added that 200M screens are fragile and require frequent replacement.) For most practical purposes the 4M --14M --35M --100M sequence is adequate for all types of fibres. The McNett Index This is a simple arithmetical relationship allowing the assessment of McNett classification to be expressed as a single figure. It is derived as follows: 1 X % 4M =a 2 x% 14M =b 3 x % 35M => c 4 x % 100M =d 5 x% -100M =e McNett Index (Ml) = a+b+c+d+e All McNett Indices lie between 100 and 500. A long fibre, all of which is retained on 4M, has an index of 100, while a finely ground fibre, ail of which passes 100M, has an index of 500. Although the McNett Index is based on a purely arbitrary relationship, it serves to bring into prominence the degree of overall shortness of a fibre, particularly after processing. For example, a useful approach in assessing the performance of fiberising machinery combines the measurement of both degree of openness and McNett index on fibre after processing under different operating conditions in the same mill. The graphical expression of McNett index in relation to degree of openness will indicate to what extent the particular mill fiberises and shortens the fibre. The same approach may be used to assess a sequence of fiberising (or dry fibre processing) operations, each of which individually may contribujp to the opening and shortening of a fibre. 01 040 1257 Bauer-McNett classifier 949 1258 Bauer McNett classifier detail of tank and agitator 01 040 1259 O verflows Water in Side view Bauer McNett classifier 01 040 1200 Screwed spigot into base of McNett vessel Bauer McNett classifier, 12 Length sorting of asbestos textile fibres 13 Experience has shown that the only reliable method of determining the fibre length of long asbestos is by the manual separation of a suitable sample into length groups. Each length group is then weighed and its percentage of the whole sample deter mined. No machine has yet been devised to enable this separation to be made automatically. In relation to the maximum separable length which can be sorted by means of the Quebec Standard Testing Machine or the Bauer McNett classifier, manual separation remains the only method whereby fibres of 7' length and over can be classified. The manual length sorting of fibres requires time, patience and skill in manipulation if no mechanical aid is available. The test method is considerably aided by the Suter-Webb comb sorter, a device developed for the length sorting of cotton and wool fibre and the like, and adapted for use with asbestos fibres. Equipment 1 For unaided length sort: Velveteen pads (white for amphibole fibres, black for chrysotile fibres) mounted on stiff board or aluminium sheet; two pairs wide o tweezers with prongs lined with soft rubber; hard rubber roller and steel plate; an analytical balance, sensitivity 1 mgm. 2 Alternatively; the Suter-Webb comb sorter, adapted for use with asbestos fibres, complete with all accessories for manipulating fibres (see page 1 3/3). Method 1 Preparation of Sample Take approximately 25 gm of the sample of fibre, and repeatedly divide this sample by halving until a representative 3 gm portion is obtained. Place the fibres portion by portion on the steel plate and fiberise the crude stalks by passing the roller over them in longitudinal direction. Spread the fibres out on a velvet pad and take five pinches of them to obtain a 1 gm sample, repeating the procedure to reduce this 1 gm sample to 0.2 gm. 2 Sorting by Manual Method a Separate the 0.2 gm sample into small groups aligning the fibres in each group by pulling them lightly between two pairs of tweezers. Lay the fibres in parallel alignment on a velvet pad, teasing them out as much as possible. b Cut a number of narrow strips of paper into lengths according to the length groups devised. A useful series is: 1, less than '; 2, ' to 7'; 3, 7' to J'; 4, J' to 1'; 5,1' to 17T*; 6,17' to 2'; 7, over 2*. Place the strips on a velvet pad, parallel to each other with 1' gaps between them. c Pick the asbestos fibres one by one, matching them against the strips of paper and laying them alongside each. When all the fibres have been sorted, weigh the amount in each length group. 3 Sorting with the Suter-Webb Comb Sorter The Suter-Webb sorter consists of two banks of 16 fine steel combs, each set of combs being spaced by ?' from the next. Sixteen length groupings are thus available. a Commencing from 2a above, the fibres are spread uniformly on the left hand bank of combs. To facilitate this, small particles of the sample held in the tweezers are opened up by pulling them over a single comb on the right hand bank before laying them on the left hand bank. 01 040 1262 b Drop the left hand bank of combs one by one, extract with the tweezers all pro truding fibres and transfer them to the right hand bank. Lay the fibres in this bank allowing of fibre length to protrude from the front comb. ____ . .. . ' .. -.<3sr. c When all the fibres have been so transferred turn the bank of combs round and commence extracting all the fibres which protrude from this side. These will constitute the length group of fibre over 2* in length. Put these to one side on a velvet pad. Drop the combs one by one and extract the protruding fibres so that a number of length groups diminishing in steps of are obtained. When all the fibres have been sorted, weigh the amount in each group. Results f The length distribution of the sample may be expressed in terms of the percentage weight of fibre in each fraction. 2 The results may be expressed visually in a block histogram, putting length of fibre on the vertical co-ordinate and weight along the horizontal co-ordinate. The weight of each group is marked off in order of decreasing length from the left hand side of the graph paper. 3 The sorted fibre sample may be photographed for permanent visual record. Each length group is spread out side by side on a velvet pad, starting with the longest group at one end, aligning the bottom ends of all groups along a straight line. A photograph of this array indicates both length distribution and textural charac teristics. 01 040 1263 a Rotap Dry Sieve test 1-4 The Rotap dry sieve test, described in the 'Manual of Testing Procedures for Chrysotile Asbestos Fibre', is more useful on chrysotile fibres, where it can be applied as a classifier. The action of the Rotap sieve shaker is such that it imparts a horizontal oscillatory motion to a pile of sieves, while at the same time giving a vertical tapping action to the pile. A series of 8' diameter Tyler standard sieves are used, a typical descending sequence for Group 3 fibres being 3M, 4M, 6M, 10M, 20M, 35M, Pan. The test does not classify amosites and blue asbestos fibres in terms of length. This machine however possesses the useful property of separating the medium and short grades of these types of fibres into fiberised material and non-fiberised spicules. The fiberised material fluffs up and remains on the top three screens, while spicules fall end on through the lower screens. Equipment 1 Rotap Testing Sieve Shaker complete with automatic timer. The machine operates at 154 4 taps per minute, at a speed of 285 rpm (UK Suppliers: International Combustion Products Limited.) 2 Tyler Standard Mesh sieves: 3M (or y' mesh), 4M, 6M, 10M, 14M, 20M, 28M, 35M, 65M and Pan, 3 Balance capacity 200 gm. sensitivity 0.1 gm. Method Screen sequences, weights of fibre and test duration times are given in the table below. 1 Weigh the specified amount of fibre into the top sieve of the sequence chosen. Close the nest of sieves into the Sieve Shaker, set the automatic timing switch to the required time and switch on the machine. 2 At the end of the test period, weigh out the amount of fibre collected on each sieve and in the pan. Results Express results as the % amount of fibre retained on each sieve. Table of screen sequences, sample sizes and test durations for Rotap Sieve Tester Screen sequences: Fibre type Mesh Amosites and blue asbestos. Group 4 chrysotiles Group 5 chrysotiles Group 6 and 7D chrysotiles 3, 4, 6,10,20,35. Pan 4. 6,10, 20, 35, 65. Pan 6.10.14.20.35.65^ ft 4 n Sample sizes and test durations: Fibre group I Sample size Amosites and blue asbestos 4 chrysotiles 5 gm 50 gm 5 chrysotiles 50 gm 6 and 7D chrysotiles 100 gm I Test Duration 30 min 10 min 10 min 10 min Rotap sieve shaker <H 040 1266  ~\ --i 'jar' ii -\ t r\ l~TM A i ij ii Of 040 1267 vj i Measurement of Degree of Openness 20 An assessmen; of degree of openness is probably the most important test which can be applied to asbestos fibres. The test method involves measurement of the rate of flow of air through a tightly packed plug of fibre. The technique has the advantages of rapidity and of not interfering in any way with the characteristics of the fibre, which can be used again in other tests. The two types of air permeability apparatus hereafter described are the Blaine Dyckerhoff apparatus, and the Rigden apparatus. The principle of operation of both these is identical, but there are certain differences in manipulation. The plug of asbestos must be contained in an accurately dimensioned air per meability cell, and a description of such a cell suitable for use with amosite and blue asbestos is included. 01 040 1268 Blaine Dyckerhoff Air Permeability tester 21 Equipment 1 The Blaine Dyckerhoff apparatus consists essentially of a U-tube of accurate bore. one end of which is connected to an air pump and to the air permeability cell, the other end being free to atmosphere. The U-tube is filled up to a prescribed level with the liquid supplied with the apparatus. By operating the air pump the liquid is raised in one limb of the U-tube. The liquid is then allowed to fall under its own volition towards its equilibrium level, as it does so, sucking air through the plug of fibre in the air permeability cell. The time taken for the liquid to fall between two predetermined points is recorded automatically on a clock. This time is a measure of the degree of openness of the fibre. O The diagram on page 2-1 /3 shows the essential parts of the apparatus. As received from the manufacturers, the U-tube and liquid are packed separately. The apparatus should be set up as follows. a Fill the U-tube (1) with the liquid supplied, up to within about 2 mm of the ring scratched on the longer limb. b Unwrap the electrode assembly (2) and insert it into the shorter limb, ensuring that the plug is pushed home. c Check the oil level (3) and if necessary, add more liquid drop-wise until the bottom of the meniscus aligns with ring. (It may be necessary to check the oil level from time to time, when the apparatus is in operation.) d Push the end of the longer limb into the wide rubber tubing (4) attached to the valve assembly (5). Clamp the U-tube in position on the base of the clock cabinet with the clamp (6). e Connect the apparatus to the mains electricity supply. 2 A balance of capacity up to 200 gm, sensitivity to 0.1 gm will be required for weighing samples. 3 Porous paper plugs, and filter papers for use with the Blaine Dyckerhoff cell. (These are supplied with the apparatus.) Method 1 Weigh out 50 gm of the sample of fibre to be tested. 2 Prepare the cell (7) by placing the perforated metal plate (9) in the bottom, laying upon this a filter paper (10). 3 Put the fibre in the cell in small quantities at a time, ramming the fibre down firmly with the packing rod provided. (This operation will be facilitated with a wide mouthed metal funnel, made to a suitable size to fit into the top of the cell.) When all the fibre is in the cell, cover the fibre with the flow distributing plate (11), with its wire mesh against the fibre. 4 Insert the cell plunger (12) and ensure that it is tight against the top edge of the cell body. It may be necessary to place the complete cell in a vice to compress the two parts together. 5 Place a porous paper dust plug (8) inside the bayonet fitting on top of the clock cabinet. Attach the ceil to the bayonet fitting twisting it to ensure a tight fit. 01 C I method 1 Switch on the apparatus. Turn the hand wheel operating the air piston, so that the continued liquid rises in the left-hand limb. Observations should be made at the back of the apparatus to ensure that it functions correctly both mechanically and electrically. The oil level will begin to rise in the right-hand limb as soon as the air piston has been drawn to its fullest extent. When the oil level touches the middle electrode, the clock will start, stopping when the oil level touches the top electrode. r The time T, in seconds recorded on the clock is proportional to the degree of open ness of the fibre. (See page 2-4/1 and Table I, page 2-4/3, for interpretation of results.) Faults in 1 Operation Incorrect functioning of the apparatus arises through faults developing at the electrode assembly. These result in the clock failing to start until the oil level has risen up to several cm above the end of the middle electrode, or even failing to start at all. The following points should be observed: a The electrodes must not touch each other, nor must they touch the side of the glass tube. If they do, they must be re-aligned so that they are equidistant from each other and from the sides of the tube. a The electrode holder must not be allowed to be wetted with oil, otherwise this will cause a short in the electrical system. If it has inadvertantly become wetted it should be taken out, cleaned with alcohol and allowed to dry. The inside rim of the left hand limb should be wiped free of oil before re-inserting the electrode assembly. c Electrical polarisation of the liquid may occur if the apparatus is left switched on for long periods of time. To avoid this it is advisable to switch the apparatus on only during the period of making a measurement d If the apparatus still does not operate satisfactorily it may be found necessary to improve the conductivity of the liquid by adding to the liquid 2 to 3 mg of potassium chloride crystals. 2 Air leaks. These may develop in the valve assembly or across the rubber cushion between the bayonet fitting and the cell. It is advisable to smear silicone vacuum grease inside the rubber sleeve (4) and round the chamfered rim of the bayonet fitting. a Test for air leaks by smearing petroleum jelly or silicone grease round the top of the bayonet fitting and covering it with a ground glass plate. Raise the oil level in the left hand limb. The level should remain stationary for at least ten minutes. Fit the cell in position, without the cell plunger, and repeat the operation with a ground glass seal over the top of the ceil. b In the event of a persistent air leak, strip down the valve assembly (5) and examine the rubber sleeving on the non-return valve. 01 040 1270 Aiternative Cells 22 The cell supplied with the Blaine Dyckerhoff apparatus will accommodate 50 gm of an average chrysotile fibre, without the need to use a great deal of force to close the cell. The ceil will accommodate 50 gm samples of the shorter, less open amphibolo (ibros, hut usually tho dry hulk o( amphibolo fibres is so much groator than that of chrysotile that it is not possible to pack tho requisite amount into tho coll, l-'utlhor difficulties arise with long aa osite ami blue fibies, which will not pack eaii5ia. (i<dlv in a nntU'w cell. If loss m m tho mniiieitP nmciiiit i>f fibto is pnckptl into tlio i-oli llton Tni-tiiia uillbt lo iiitiinluCnil In dllnw CttmpnManil of Ihn frlndinOft f<jf dilierent weights of fibre. Further factors must be introduced to account for the different specific gravities of amphibole and chrysotile fibres. For these reasons, two modified cells are used, each mounted in a small hand press to facilitate packing of the fibre to a fixed volume. The smaller of the two cells has an internal diameter of 1 y', and is intended for general purpose use with all medium and short types of asbestos fibres. The larger cell has an internal diameter of 3' and is intended for use with long amphibole fibres. Both cells provide fibre bed depths of 1The essential details of this design of ceil are shown diagrammaticaily on page -2 2/2 These cells have been designed for connection to and use with any type of air permeability apparatus suitable for measuring surface areas of asbestos fibres. They are therefore referred to as the 1Universal cell and the 3' Universal cell. To connect these cells to the Blaine Dyckerhoff apparatus, it is necessary to remove the existing Dyckerhoff cell, and fit a screwed spigot into the hole of the bayonet fitting at the top of the clock cabinet A length of rubber pressure tubing should then be connected between the spigot and the cell. Method a Disconnect the cell from the rubber tubing before attempting to fill it with fibre. b Refer to Teble II, page 2-4/3 and choose an appropriate weight of fibre according to its visual decree of openness. Weigh out the fibre sample and pack it into the cell using a funnel and a ram, adding the fibre in small quantities of about 5 gm at a time and pressing each lot down firmly. c Fit the piston into the cell and return the whole into the press, tightening up until the edge of the piston mates with the rim of the cell body. d Connect the cell to the Blaine Dyckerhoff apparatus and make the air permeability measurement as described above. e The time T, in seconds is proportional to the degree of openness of the fibre. 01 040 1271 -1 Essential details of 01 040 1272 Blaine Dyckerhoff apparatus /c' 1.000+1--.005' on assembly Assembly of universal air-permeability cell 01 040 : 273 Blaine-Dyckerhoff apparatus with universal cell 01 040 1274 esterMir Mar .a? 2 J :v / 23 xJ Equipment 1 The Rigden apparatus is a simpler and less expensive apparatus man the Blaine Cyckerhotf, certain elements of its construction making it nevertheless siightly more accurate and less variable than the latter. The diagram on page 2-3/3 shows the essential part of the apparatus. There are no electrical components and the apparatus does not include a clock or an air per meability cell suitable for asbestos fibre. The instrument as supplied has all the necessary internal connections made. As it may be used in alternative ways, certain additional connections are included. These may be ignored, but the following points should be checked. a In normal operation the twin bore 3-way tap (1) should be left in the position shown (page 2-3/3). The connection (7) between the top of the limb L and the top of limb R should be maintained in position so that limb R is not connected to atmosphere. b Limb L has a side connection at the top to the spigot (3) marked 'cell'. This spigot should be ieft clear to atmosphere at ail times, and the celts should not be connected here. Ignore the spigot (2), marked 'gauge'. c Connect the hand pump to the spigot (4) marked 'pump', at the side of the cabinet. d Connect a piece of rubber pressure tubing to the spigot (5), projecting up from the base at the front of the cabinet. The air permeability cell is connected to this tubing. 2 A supply of dibutyl phthalate will be required for filling the apparatus.-(This is obtainable from the manufacturers.) 3 A stop watch or stop dock. 4 A 1" or 3' Universal air permeability cell of the design recommended on page 2-2/1. Setting up the a Rigden Apparatus Filling with oil: Turn the tap (1) to the up position and pour the dibutyl phthalate in through the tube (8), using a small funnel to facilitate this. Tip the instrument forward while doing this, to avoid oil escaping down the side connection at the top of limb L Add the oil up to the mark 'Oil Level', ensuring that when the upper part of limb L has drained free of oil, the oil level is correct. Return the tap (1) to its original position. b Checking for leaks: Turn tap (6) to suction and operate the hand pump, raising the level of oil in limb R above the line marked 'start'. Turn tap (6) to 'off. The oil level should remain stationary for at least ten minutes. Check the rubber tubing con nections at the back of the apparatus if it does not do so. Ensure also that the taps (1) and (6) are sufficently greased with petroleum jelly, and that their bores are not choked with grease. Connect the air permeability cell to the spigot (5). Remove the cell piston and cover the upper rim of the cell body with a greased ground glass plate. Turn tap (6) to 'call'. The oii level will fall a little, but should then remain stationary provided that the cell and its relevant connections do not leak. 01 040 1275 Method a Turn tap (6) to 'Suction' before attempting to fill tne cell with fibre. b Refer to Table III, page 2-4/4 and choose an app. .riate weight of fibre according to its visual degree of openness. Weigh out the fibre sample, and pack it into the cell using a funnel and a ram, adding the fibre in small quantities of about 5 gm at a time, and pressing each lot down firmly. c Fit the piston to tne cell, return the whole into the press, tightening up until the edge of the piston mates with the rim of the cell body. d With tap (6) at 'suction' operate the hand pump and raise the liquid ievel in limb R to about 1 cm above the line 'start'. Quickly turn the tap (6) to 'off'. e Start the watch when the bottom of the meniscus level reaches the line 'start', and measure the time taken for the bottom of the meniscus ievel to reach the line 'B'. (Line 'A' marks exactly half-way.) f The time T, in seconds recorded, is proportional to the degree of openness of the fibre. Essential details of Rigden apparatus 01 040 77  -V t Rigden apparatus with universal cell 01 040 1278 Air Permeability Tests using Blaine Dyckerhoff Apparatus and 1 y' Universal Cell. Amosite, crude Wt of test sample .Vieesureo Dyckerhoff time (T) FRF = T x1 Surface Area = S80 V ~T- 46.5 gm = 15 sec 5 units 3800 cm Vgm 2 Blue Asbestos, standard Wt of test sample =, 38 gm Measured Dyckerhoff time (T) = 30 sec FRF =Tx2 -- 60 units Surface Area = 1380 V T ss 7500 cm Vgm 3 Chrysotile, standard Wt of test sample Measured Dyckerhoff time (T) FRF = T x 0.98 Surface Area = 1230 V T" 3. 36.7 gm 110 sec = 108 units = 12800 cm Vgm Not* on the Theoretical Background 'The Manual of Testing Procedures for Chrysotile Asbestos Fibres' recommends that the Blaine Dyckerhoff apparatus be calibrated initially against materials of known surface areas. These of course may not be immediately available, and in any event they should be fibrous materials similar to asbestos. Their surface area should also have been determined by an air permeability method. Tables I. II, 111 have been drawn up to eliminate the calibration procedure. The values for FRF and surface area have been derived from first principles by the KozenyCarman equation, taking into account the physical dimensions of the apparatus, and the cells, and the densities of liquids used. A further factor has been introduced to account for the viscous drag of liquid in the narrow U-tube of the Blaine1 Dyckerhoff apparatus. This drag has the effect of making the time T, measured on this apparatus larger than that theoretically calculated. The factor introduced corrects for this effect, but only in so far as making the Blaine Dyckerhoff readings directly comparable with Rigden readings. The Rigden apparatus has a wider bore U-tube than the Blaine Dyckerhoff, and is less susceptible to the effect of viscous drag liquid in the tube. It should be recognised that with either of these types of apparatus, it is only possible to obtain apparent surface area measurements. Any such measurements made on asbestos fibres by air permeability methods are lower than those found by gas absorption methods, but for all practical purposes the air permeability method gives comparable, consistent and useful results. References Kozeny: Carman: Lea & Nurse: Rigden: Ger. Wien. Akad. 1927 Vol 136a, p 271 Trans. Inst. Chem. Eng., 1937 Vol 15, p 150; JSC1 Vol 56 JSCI, 1939, Vol 58, p 277 JSCI, 1943, Vol 62, p 1 JSCI, 1947, Vol 66, pi 30 01 040 1280  i d <rn W ^ 4 W <b i W a 4 2-4 The results may be expressed as follows: 1 For routine measurements always made on the same type of fibre it would be sufficient to decide on a suitable weight of sample and express degree of openness simply as seconds (T). It is to be emphasised that this method does not give directly comparable results for amphibole and chrysotile fibres, nor is it suitable if used to compare a single grade of fibre in widely differing degrees of openness. 2 The measurement in seconds (T) is multiplied by a suitable factor, accounting for weight and type of fibre to give an expression of degree of openness called Flow Resistance Factor (FRF). This expression is comparable for all fibres and gives a scale of values for degree of openness proportional to 1 (fibre diameter)2 3 Alternatively the square root of (T) is multiplied by a suitable factor accounting for weight and type of fibre to give an approximate Surface Area (cmJ/gm). This expression is comparable for all fibres and also with other methods of measurement of surface area. It is proportional to VFRF. Tables I, II, III give a number of factors for converting T on either type of apparatus to FRF or surface area, whichever is desired. A conversion factor for the Blaine Dyckerhoff with the Blaine Dyckerhoff cell is included. For purposes of international comparison of degree of openness of asbestos fibre, a figure in surface area terms is to be preferred, as this can be understood indepen dently of the type of air permeability method used. In applying these factors, the user has the choice of several weights of fibre to be packed into the ceil, depending on the degree of openness of the fibre. The more open amphibole fibres are, the more difficult it becomes to pack a specified weight of fibre in the cell. Chrysotile fibres will consolidate with less difficulty over a wide range of degrees of opening. The tables give three choices of weight of amphibole fibres, designated 'Crude', 'Standard' and 'Very Open". The 'Standard' weight will be found satisfactory for most applications. Only two such weights are necessary for chrysotile fibres. .J The following examples indicate the type of calculations and results involved : 01 040 1279 Application Blaine-Dyckerhoff cell witn the Blaine-Dyckerhoff apparatus. Amosite and Blue Fibre : Weight of Fibre ! in Cell (gm) | FRF Units \i Surface Area cm*/gm ___ 1 cOn Standard Very Open Chrysotilo Standard i ^ j i 1 t j 50 ! Tx 1.91 T x 5.01 ; 1 j T x 0.84 1250 \/~T~ ; 2120V~T~ ! 1170 V T Blaine-Dyckerhoff clock reading = 7 sec. w ir - w>i S - at r-- j tl Gw i ^~ (L* iJ cs A''33 Constants Application CAFCO Universal cells with the Blaine-Dyckerhoff apparatus. 1 Universal Cell Amosite and Blue Fibre j Weight of Fibre j in Cell (gm) FRF Units : Surface Area j cmVgra Crude Standard Very Open Chrysotile Standard ! 46.5 j 3S.0 ! 33.3 | J36.7 i T x 1.0 Tx 2.0 T x 3.0 T x 0.98 | 930 V T ! 1330 V T~ j 1690 V~T~ ! j 1230 V T~ 3' Universal Cell Amosite and 3luo Fibre Crude ! 153.2 j 7 x 1.89 i 1340 V~f~ Blaine-Dyckerhoff clock reading = T sec. Note Use the 1' cell for medium and short amosite and blue fibres. Use the 3' ceil for long spinning blues and long amosite fibres. 01 040 1281 ^ j M ** *--k f-J vacs Arsa Constants Application CAFCO Universal cells with the Rigden apparatus. 14' Universal Cell Amosite and Blue Fibres Crude Standard Very Open Chrysotile i Weight of Fibre j in Call i ! 50.0 i 2S.3 1 30.0 j j 1 FRF Units l ! T x 0.53 ' Tx 1.35 T x 2.85 j Standard j 36.7 : T x 0.68 Surface Area cmVgm 720 V~T 1140V T 1 650 V T 1050 V~T~ 3' Universal Cell Amosite and Slue Fibre Crude 153.2 Tx 1.35 1140 V T Rigden stop-watch reading = T sec. Note Use the 1 ceil for medium and short amosite and blue fibres. Use the 3' cell for long spinning blues and long amosite fibres. o O O 01 040 12S2 /"s H f" f;. r; ? F !' FM " <3 <3 Vj L_lJ ii\di 01 040 1283 Grit and Dust Contents 31 The Quebec Standard Asbestos Testing Machine can be usefully modified for this purpose. The fourth tray or pan should be replaced by a similar pan, but of half depth, and superimposed on this there should be a half depth tray having a 50 mesh US Standard screen (or its Tyler equivalent). The Quebec Standard machine possesses the facility, through its oscillatory action, of concentrating grit beneath the fibre on the 10 mesh and 50 mesh screens. A grit and dust separation may be made in the following steps. 1 Use 16 oz (450 gm) crude fibre or 100 gm milled fibre for each test. 2 On completion of the sieve cycle of the machine separate the fibre from each tray, spreading it out on a fiat surface and hand pick from it any particles of grit retained in the fibre. (This is a simple operation with the material retained on the first second and third tray, but it is more difficult with the -f50M fraction). Combine the hand-picked grit with that retained on each relevant tray and weigh it in grammes. Detailed results are usually expressed as: % -ry' grit % -r4M grit % -10M grit % -7-50M grit The material passing 50M consists of rock dust and fibre fines, and the amount of fibre it contains may well be variable. For practical purposes the material collected in the pan can be regarded as dust, weighed back in grammes and expressed as: % --SOM dust Ot 040 1284 Conou: 32 The colour of biue asbestos fibre varies from dark blue for deep-mined fresh fibres to a brownish ciscolourea blue for weathered fibres. Amosite fibre varies from ash grey for fresh fibres to light reddish-brown for weathered fibres. Chrysotiles are white, cream, or even pale grey coloured. The only satisfactory way of making colour tests of asbestos fibres is to compare the fibre visually with a standard acceptable to the user. Matching tests should always be done under identical conditions. The standard fibre should be packed into transparent containers, using a fixed weight of fibre and packing into a fixed volume. (1' diameter glass test tubes or clear poly styrene pill boxes are suitable.) The unknown sample should then be packed in a similar container under the same conditions, and visual comparison made. 01 040 1285 K' 7 Vc r c V. 01 040 1286 w \\t/.O-> i5 UI - j K and rsitratson sesjs 4-1 The object of these tests is to provide data on the properties of asbestos fibres in an asbestos-cement slurry under conaitions which, as far as possible, are intended to resem.bie those in the vats and on the blankets of an asbestos-cement machine. By using an asbestos-cement slurry the wet voiume test becomes independent of the initial pH and temperature of the water used. 3oth these parameters have marked effects in tne usual method of wet volume testing where fresh water and asbestos fibres are employed, and lead to wide variations in the test figures. The filtration properties of asbestos fibres are also highly dependent on both the pH and temperature of the prepared suspension of fibres in water. The effect of the cement in an asbestos-cement slurry is to provide what is virtually a buffer solution of high alkalinity so that dependence on pH can be eliminated in the filtration test. The test cannot be made independent of temperature and steps must be taken either to make the test at constant temperature, or to correct the results for tem perature, as explained later. The method of test both for wet volume and filtration requires an asbestos-cement slurry to be made with a preferred solids content of 5%, the solids having asbestos:cement ratios corresponding to those used in practice. (For example, asbestos:cement 15:85 for pipe furnishes and 12:88 for sheet furnishes.) Standard techniques have been devised for both tests, it is however both con venient and advantageous to use the board making apparatus described in subsection 4-2 for performing the filtration test. Apparatus required Wet Volume Tests (Standard Procedure) 1 2000 ml stoppered measuring cylinders. 2 Mechanical inverter for measuring cylinders, with speed of 30 rpm and auto-stop after 30 revolutions. See pages 4-1 /6, 4-1 /7, 4-1 /8 for details. Filtration Test (Standard Procedure) 1 2500 ml capacity brass filtration cylinder, 3' (76 mm) internal diameter, having a detachable cone-shaped bottom end, screw fitted to the cylinder; the cone having an internal 3' (76 mm) diameter, 50 mesh screen and a j' (6 mm) outlet cock. 'N The screen should be brazed to a y' (6 mm) wide annular ring which locates against a rim inside the upper portion of the cone, and should be backed by a soft rubber gasket. (See page 4-1 /9.) 2 The outlet cock of the filtration cyiinder is connected to a vacuum pump capable of pumping down to pressures of less than 5' (125 mm) mercury, at capacities of more than 5 litre/min. A vacuum gauge must be included in the circuit, together with a bleed vaive or other means of control so that the vacuum can be adjusted to 5' (125 mm) mercury. A mechanical vacuum pump, as such, is not recommended here, since efficent and complicated safeguards must be provided to prevent water vapour from entering the pump chamber. It is preferable to use a fluid pump such as the Watson- Marlcwe Peristaltic Pump (Model HSHfi) or a small Mono Pump (Model Ml3). Both of these will transport water and simultaneously provide adequate vacuum. The Mono Pump must be provided with a separate inpMit wateJj||a|l asJhiatypjyjf pump cannot be allowed to run dry. A ^* A simpler metnod employs a water vacuum pump such as is generally used for filtration processes in the laooratory. Such a pump can only be recommended J where the direct water mains pressure is sufficient to give the vacuum required. 3 A stop-clock is required for making time measurements in the filtration test. Filtration Test (Alternative Procedure) The board making apparatus described in the subsection beginning on page 4-2/1 is eminently suited for filtration testing, and in fact the ooard test as described includes time measurements to determine the filtration properties of the slurries from '.vnich the boards are prepared. Such measurements are however only comparative within the particular conditions of the board test, and the filtration test described here should be made under the standard conditions set out below. The advantages of using the boara test apparatus lie in the larger volume of slurry, and hence iarger and more representative fibre samples; and in the larger area of filtration used, in comparison with the standard apparatus described above. Techniques in Wet 1 Volume and Filtration Measurements Standard Cement Both the composition and fineness of cement will affect the results of these tests. The compositions, and hence rates of hydration, of cements vary considerably and the fineness of grinding may be such that surface areas of cements lie between 2200 and 4000 cm2/gm. The normal products of different cement works cannot be expected to provide identical results in these tests. The cement component is usuaiiy, however, the one invariable in the raw materials used in asbestos-cement works, and therefore it should be chosen as the standard for these tests within that particular environment. If possible the fineness of the cement should be stan dardised at say 3000 -- 100 cm2/gm, and the standard cement should be kept in air tight containers. 2 Process Water In asbestos-cement manufacture, it is usual to recirculate the water used in process. This water is saturated with lime, gypsum, and soluble alkalis and traces of other ions dissolved out of the cement used in process; all these affect the state of suspension and the filtration properties of the asbestos fibres in the slurry. To ensure that these effects are repeated on the laboratory scale, supernatant water from wet volume tests and filtrates from filtration tests should be retained for use in subsequent tests. All this 'process' water should be kept in a closed polythene container for use as required. 3 Temperature The filtration properties of an asbestos-cement slurry are dependent on temperature to the extent that standard filtration times may decrease by as much as five seconds or more for every 1 C rise in temperature of the slurry. While changes in the viscosity of water come into play here, increases in temperature have a marked effect on the gel phases formed in the early stages of hydration of cement, these tending to form larger and more stable particles as the temperature rises. Different types of cement will of course produce different results. Over a fairly wide range of temperature (5 to 25C) the decrease in filtration rate per degree C is almost constant, so tnat as an alternative to preparing all filtration tests at constant temperature, a correction can be made for whatever temperature at which a test is performed. A calibration graph should be prepared from observations of the filtration rate of a standard asbestos-cement slurry at different temperatures, and a suitable reference temperature should be chosen depending on the mean ambient temperature of the environment. The slope of the calibration graph is not affected by different types of asbestos fibre, provided that all other conditions are kept constant. 01 040 1288 4 The Degree of Opening of the Asbestos Fibre As a general rule asbestos fibres will give higher wet bulk volumes and higher 3 filtration times in the asbestos-cement slurry test, as the degree of opening (or surface area) of the fibres is increased. Chrysotiles deflocculate in alkaline solutions however, and thus the effect of opening on this type of fibre in the wet bulk volume test is much less marked than on amphibole fibres (amosite, blue asbestos, etc). On the other hand the filtration properties of amphibole fibres are much less dependent on degree of opening of fibre tnan are chrysotiie fibres. The results of wet bulk volume and filtration tests on different types of asbestos can therefore be strictly compared only at some constant reference point of surface area, aithough for most practical purposes a compromise can be reached by reference within a range of surface areas appropriate to asbestos-cement manu- ' factoring processes. Methods The test methods are given in step by step descriptions in the following pages. Both the filtration and wet volume tests include two separate procedures. One procedure concerns the testing of individual grades of fibre, the other concerns the testing of blends of fibres. For purposes of standardisation such blends always comprise 80% chrysotiie fibre, and 20% blue or amosite fibre. The objective here will be a comparative assessment of one of the components of the blend by varying its grade or degree of openness, the other component being invariable. The choice of a standard chn/sotile, blue or amosite fibre will depend on local circumstances allied to the requirements of an asbestos-cement plant or similar process. Results -1 Results should be reported as: WV (A/C) ml at 20 C (eg) and Filt (A/C) secs at 20C (eg) 2 The complete properties of a fibre grade may be obtained by measuring wet volume and filtration properties at a number of different degrees of openness. Graphs showing the variation of these properties with degree of openness (surface area) may then be drawn up. For purposes of absolute comparison wet volumes and filtration times of fibres at a surface area of 10,000 crr.Vgm should be obtained from such graphs. For general purposes of comparison wet volumes and filtration times of fibres may be taken for degrees of openness in the range 6000 to 10,000 cmVgm, but the exact degree of openness should be stated. 3 Test results generally fall into the following groups: j Vi'V (A/C) ; Standard Procedure !^ Chrysotiie j 250 to 700 put A/C Standard Procedure sec ` Filt A/C Ait. Procedure i sec i 600 to 900 ! ICO to 200 Blue Amosite ` 1000 to 1500 i 1 COO to 1800 i 200 to 350 to100 200 i 50 to 70 ! 40 to 60 1i Filtration times of amosites ar.d blues are generally independent of degree of opening; those of chrysotiles are dependent on degree of opening, but do not /-"V foliow a logical pattern. 01 040 1289 V/st Volume . ect- WV (A/C) oisndcrd Procedure Mixes 5% slurries (20:1 water:solids). Tost A For one grade of fibre , Test B j for blends of 80 per cent chrysotile . and 20 per cent blue or amosite 1 1400 ml process water 2 15 gm fibre 3 85 gm cement 4 600 ml process water | 1 1400 ml process water ; 2 12 gm chrysotile fibre | 3 3 gm blue or amosite fibre j 4 85 gm cement j 5 600 ml process water Method 1 Put the components of the mix into an adequately sized can in the order given above excepting the last 600 ml water. Mix the slurry vigorously by hand with a large spatula for one minute starting from the time that the fibre is added. 2 Transfer the slurry to a 2000 ml cylinder and wash down and make up with the 600 ml water. O Fit the stopper to the cylinder and clamp the cylinder into the mechanical inverter. 4 Run the inverter for one minute. 5 Take the cylinder from the inverter and stand it on a level bench, starting the stop clock at the same time. 6 Measure the wet volume of the solids after the slurry has settled for 30 minutes. Filtration Test -- F:2t (A/C) Standard Procedure Mixes 1.75% slurries (55:1 water: solids). Test C For one grade of fibre Test D For blends of 80 per cent chrysotile and 20 par cent blue or amosite 1 1400 ml process water 2 5 gm asbestos fibre 3 30 gm cement 4 600 ml process water 1 1400 ml process water 2 4 gm chrysotile asbestos 3 1 gm blue or amosite asbestos 4 30 gm cement 5 600 ml process water Preparation of the 1 Apparatus Testing for leaks. Fit a 3' (75 mm) diameter metal disc in place of the screen and fill the cylinder with water. There should be no leakage into the cone or past the screw threads. 2 Apparatus constant. Place a 3' (73 mm) diameter filter paper on the 50 mesh screen, and replace it in the apparatus. Put 2C00 ml water in the cylinder. Ooen the outlet cock and measure the time taken for the apparatus to drain completely - no: under vacuum. This time is the apparatus constant which should be checked occasionally. Corrosion or clogging of the screen or outlet cock will show up :n an increase in this constant. 01 040 1200 Method 1 rut the components of the mix into an adequately sized can in the order given aoove, excepting the last 600 ml water. Mix the slurry vigorously by hand with a iarge spatula for one minute starting from the time that the fibre is added. 2 Transfer the slurry to a 2000 ml glass cylinder and wash down and make up with the 6C0 ml water, Pit a stopper in the cylinder and clamp the cylinder in the mechani cal inverter used for wet volume testing. Run the inverter for one minute to complete the mixing of the slurry. 3 Meanwhile, place a dampened filter paper on the 50 mesh screen in the cone of the filtration cylinder. Screw the cone up tight to the cylinder and adjust the gauge to 5" 1' (125 mm -- 25 mm) Hg vacuum. 4 Quickly empty the slurry from the glass cylinder into the filtration cylinder. Start the stop clock and at the same time open the outlet cock of the cylinder. 5 The filtration time is measured from this moment until the vacuum breaks after complete filtration of the 2000 ml slurry. The vacuum gauge should remain steady during the whole period of filtration. Filtration i esting - Flit (A/C) Alternative Procedure Mixes 5% slurries (20:1 water: solids). Test E For one grade of fibre Test F For blends of 30 per cent chrysotile and 20 per cent amosite or blue 1 3300 ml process water 2 25 gm fibre 3 141 gm cement 1 3300 ml process water 2 20 gm chrysotile asbestos 3 5 gm amosite or blue asbestos . 4 141 gm cement 1 Use the board making apparatus for mixing and for the filtration test. 2 Put the components of the mix into the mixer in the order given above, and mix for one minute. 3 Meanwhile, cover the screen of the vacuum filter box with a moistened filter paper, and start the vacuum pump. (The pump should be pre-adjusted to give a vacuum at 5' 1' Hg (125 mm -- 25 mm) with the vacuum line to the filter box closed at the filter box end.) 4 Drop the slurry into the filter box and start the stop clock. 5 The filtration time is measured from this moment until the vacuum breaks after complete filtration of the 3300 ml slurry. The vacuum gauge should remain steady during this operation. 01 040 129.t Timer Starter Main drive: geared motor unit 0.5 HP. 35 r.p.m. output 01 040 IS#* Principle details of mechanical inverter for wet volume test Glass specimen container Container clamp ( I Details of mechanical inverter for wet volume test .1 1 Mechanical inverter for wet volume test 01 040 1254 I ii I 85 1 -14 Measurement of Reinforcing Value 4*2 There exists a number of laboratory methods for determining this measurement, some of which require the preparation of a steam-autoclaved asbestos-cementsilica test board, and others requiring an air-cured asbestos-cement test board. An air-cure test method is to be preferred because it compares directly with the curing method generally found in large scale practice. The main advantage in the steamautoclave test method is that it provides a rapid turn-over of tests. The following standardised air-cure test technique combines the best features of a number of methods, and also provides an alternative means to that given in subsection 4-1 of measuring the filtration properties of fibres in asbestos-cement slurries. This test aims at making a number of test boards from each sample of fibre, over a range of cured and finished densities of about 1.4 to 1.75 (i.e. 85 to 110 Ib/cuft), all having a furnish of 10% of fibre. The moduli of rupture (MOR) of these boards are determined by means of a suitable tensometer, and a mean MOR at a density of 1.6 is calculated. The reinforcing value of the fibre then becomes a measure of MOR, under fixed conditions of density and fibre content. The detailed working of this method may be considerably narrowed down so that the reinforcing value of asbestos blends may be determined at densities near to 1.6 (100 Ib/cu ft). Equipment 1 Board Making Apparatus (see diagrams on pages 4*2/5,4-2/6) comprising: a 5 litre mixing vessel with 1/10 hp mixer complete with special impeller, and with delivery trough for mix. b Vacuum filter box to make 8* x 8' test boards. c A vacuum pump capable of carrying water vapour. Suitable pumps, as recom mended on page 4*1 /I for filtration measurement are the Watson-Marlowe Pump Model HSHR, and the Mono Pump Model Ml3. The latter pump must be provided with a separate input water bleed, as this type of pump cannot be allowed to run dry. d Board breaking test machine. Hounsfield Tensometer (page 4*2/9) equipped with breaking jaws for either 1' or 3' wide specimens: or similar type of transverse testing machine, such as the Zwick tester. 2 Small press with 1C* x 10' platens, about 4' daylight, capable of total working pressure of 40 to 50 tons, manually or mechanically pumped. 3 Humidity chamber, effective internal dimensions 2' x 1' x V to operate at 90 to 95% RH at normal temperatures. Water trough, similar dimensions to humidity chamber. Materials 1 Cement It is preferable to obtain small quantities, say 100 lb at a time, direct from the manufacturers. The cement should be stored in 20 lb air-tight tins, to reduce to a minimum the degree to which it air sets. The cement should be regarded as a standard material. It should be of uniform chemical composition from batch to batch, and if at all possible, arrangements should be made to have the cement ground orblended to a standard specific surface area, preferably 3000 = 100cmz/gm. 2 Filter papers No 1 Whatman paper (or nearest available) cut into 8' x 8' squares. 01 040 1296 uijsr.--. Method a Preparation of the Asbestos Fibre The many types of mill used to process asbestos fibre have effects on the fibres which vary between the extremes of disintegration (or shortening) and true fiberisation (or opening). The ideal mill fiberises rather than disintegrates asbestos fibre, but there are few laboratory mills which will satisfactorily fiberise all types of fibre. The practical disadvantage here lies in the small diameter of these mills in relation to the length of fibre, and this tends to bring about a shortening of fibres superimposed on excessive fiberisation. This effect is accentuated with mills having screens in the exit port. Laboratory mills such as the Christie & Norris, Entoleter, BOP are generally satis factory only for the shortest grades of fibre. The laboratory Pallmann Mill is suitable for all medium and short grades as used in the asbestos-cement industry, and can be adjusted to produce degrees of fiberisation similar to those given by larger mills of the same type. Ball mills and rod mills have been recommended for processing chrysotile fibres on the laboratory scale, but this method of processing does not give the best reinforcement results with amphibole fibres. When processing fibres in the laboratory for the asbestos-cement reinforcement test, a laboratory mill should be chosen and adjusted to produce a fibre having charac teristics related to those produced on the large scale. McNett classification and measurement of degree of openness would be sufficient to characterise a fibre. It is also preferable to have in the laboratory several standard fibres as processed and used on the large scale, to which laboratory tests can be referred. b Process Water As in the wet bulk volume and filtration tests, all the water used in the reinforcement test should be process water filtered from the asbestos-cement slurries used in board preparation, and re-circulated into the test. Filtrates from the slurries should be pumped into a closed polythene vessel and retained for future use. Preparation and Prepare 3 to 5 boards for each sample of fibre using for each board: Curing of the Boards 3300 m, process waler 480 gm cement (90%) 53 gm asbestos fibre (10%) 2 Place 3000 ml water in the mixing vessel, add the asbestos fibre and allow to mix for one minute; then sprinkle the cement in the vessel, and mix a further five minutes. 3 Place an 8' square of dampened filter paper on the screen of the vacuum filter box. Start the vacuum pump, remove the rubber bung from the bottom of the mixing vessel, and allow the contents to drop into the vacuum box. Wash the remnants of fibre and cement from the vessel, using a further 300 ml of water. When all the water has filtered off, smooth down the edges and surface of the board, pressing down the surface with a suitable implement to encourage further drainage. Shut off the vacuum pump, drain the vacuum box, then invert it to remove the test board. The filtration time of the slurry may be measured, in seconds, starting at the point when the contents of the mixing vessel are dropped into the filter box, and finishing when the vacuum breaks in the filter box. Filtration times measured under these conditions of test are closely related to those determined in the filtration test (alternative procedure, page 4-1 /5) the results being greater than those determined in the iatter test by a constant amount due to the grAt* thi 4 Transfer the boards one by one to the press. The boards should be pressed between several layers of filter paper backeo on both sides by a wire screen to allow escape o of surplus water (see page 4-2/6). Press each board at a successively higher pressure in the range 20 to 35 tons total pressure. Some initial experiments may be necessary, the requirement being to produce a series of boards at various finished densities in the range of density of 1.4 to 1.75. 5 Cure the Boards a For 24 hours in the humidity chamber. b For 6 days by total immersion in water. Dry the cured boards at 100C temperature for at least 16 hours. Testing the Two methods are possible here, depending on the test equipment used. The boards Boards may cut jmo a number of 6' x 1' strips, discarding the edges, for breaking on the Hounsfield Tensometer; or 8' x 3* strips again discarding the edges, for the Zwick Tester. If the tatter method is chosen, then it is preferable to prepare in the first instance duplicate boards at each density (making 6 to 10 boards in ail). A diamond or carbide-tipped wheel should be used for cutting the finished boards, but if such is not available, it is advantageous to cut the boards on a band-saw, o when they are partially cured after 24 hours in the humidity chamber. 1 Measure the MOR of the test strips, using the tensometer, and make an average of all the results obtained for each board. Retain part of each test strip for density measurement. 2 Density measurements may be made in two ways: a take pieces of each test strip after breaking in the tensometer, cut them down to a suitable size, say 1 * x 3* and grind the edges and faces smooth. Accurately measure the dimensions of these strips, determine their volume, weigh them and thus determine their density, in gm/cc units; take an average density for the board. b as in (a) take pieces of the test strips cut down to 1' x 3' size, and without any further preparation, weigh the strips in air and by total immersion in mercury. This latter method is rapid and less tedious than (a), but requires a balance with a special device for weighing in mercury. Details of this device and method may be obtained if required from Cape Asbestos Fibres Limited. 3 Make a graph of MOR against density for the average measurements obtained on the test boards. With reasonable care in preparation of the boards, the points obtained will fall in an approximate straight line (see specimen graph on page 4-2/7). Determine from this line the MOR at a density of 1.6 (i.e. 100 Ib/cu ft). This MOR represents the reinforcing value of the fibre examined. The reinforcing value may be converted into arbitrary units, using for this basis a figure of 100 for a fibre giving an MOR of 4000 Ib/sq in at a board density of 1.6 and a raw materials fibre content of 10%. By putting: test board MOR at density 1.6, fibre content 10% a scale of values for various fibres can be drawn up. 01 040 1238 Testing the Reinforcing Value of Blends Reinforcing values increase with increasing fibre contents up to a limit of ai}Cut 3% -^e above method assumes a standard furnish of 10%, but where manufacturing processes require furnishes of other amounts, say 15% as in typical a/c pipe manufacture, then it may also be desirable to make laboratory tests under similar conditions. This, moreover, leads to the more realistic applications of this test in the determination of the reinforcing properties of blends of asbestos, in such investigations the combinations of asbestos in both types and proportions are innumerable, and it is recommended that a standardised procedure along the following lines be adopted. Choose a suitable chrysotile. for example a 5R, and let this make an arbitrary furnish of say 15% in the asbestos-cement mix. Substitute in this furnish parts of amosite or blue asbestos so that the furnish is then made up of 12% chrysotile and 3% amosite or blue asbestos. Test boards may then be made up from these blends, varying only the type of amosite or blue asbestos. Having established that such furnishes give an enhanced reinforcing value, it is possible to extend the principle of test to ascertain economic blends of fibre. For example if a 15% furnish provides a reinforcing strength greater than the control blend, it should be possible to find a lower percentage furnish which will give the same reinforcement as the control. This then enables the establishment of blends of lower cost than the control blend. O O 040 1289 r\ General arrangement olbi 040 13 board making apparatus -H*.----4.0/0 -- - Board making apparatus rsiZ:.- Hounsfield tensometer with sample in test position Q40 1304 i \ 01 040 1305 andM3 3 C ! * f/' tion Loss 51 o The moisture content and ignition loss of asbestos fibre are not often required as essential properties in relation to a manufacturing process, but may be needed to meet a contract specification. Although well recognised laboratory procedures for determining these properties exist, there are certain characteristics about asbestos which necessitate special attention to techniques. Firstly, asbestos fibres have high surface area and absorb moisture quickly from the atmosphere. The analytical procedure for determining moisture content must therefore be rapid and with minimum source of errors. Secondly, the ignition loss of amphibole asbestos fibres will not be the same in an oxidising atmosphere as it is in an inert atmosphere. The conditions of measuring ignition loss must therefore be stated. Determination of Moisture Content 1 A number of proprietary makes of moisture balances are available, and it is recom mended that for general purposes, one of these be used. vJ An exact weight (e.g. 10 gm) of fibre is weighed out and placed on the pan of the balance. The sample is heated by an infra-red lamp and the percentage moisture loss is directly read off the scale. The disadvantage of this method lies in the inexactness of the temperature of the test; it may be 100C 20#C 2 Equipment i ii iii iv Accurate Method Temperature controlled oven, operating at 105C 1 C. 100 ml capacity glass weighing bottles, with caps. Dessicator. Analytical balance. Method 1 The weighing bottles should be dried in the oven and kept in the dessicator prior to use. 2 Tare the weighing bottle and cap; fill it loosely with asbestos fibre and re-weigh to obtain the weight of fibre. 3 Dry the filled weighing bottle and cap separately at 105C for two hours. At the end of this time replace the cap on the bottle and transfer it from tne oven to the dessicator. 4 Allow the bottle 15 minutes to cool in the dessicator and then re-weigh it. Calculate the % loss in weight as moisture content. Determination cf Ignition Loss Equipment 1 A temperature controlled tube furnace fitted with a work tube. The inlet end of the work tube has dual access to a vacuum pump and to the appropriate gas cylinder via a flow meter. The outlet end has a vacuum-type glass one-way tap, leading to atmosphere. A diagram of a suitable apparatus is shown on page 5*1 /3. 2 Combustion boats, approximately 10 cm long x 1 cm wide x $ cm deep. i 3 Aluminium oxide powder. 4 Analytical balance. 01 040 13C6 Method 1 Place a thin layer of aluminium oxide powder in the bottom of a combustion boat. (This will prevent fused asbestos sticking to the boat on completion of the test.) Weigh the boat, and then weigh into it approximately 2 gm of the sample of asbestos. 2 Push the boat to the centre of the furnace work tube, close the work tube by inserting the bung A and closing down the tap B. Set tap C to vacuum and outgas the work tube for 30 minutes. 3 Set tap C to the gas cylinder (oxygen or nitrogen). Open the gas cylinder valve gently and observe the gas flow. This will start rapidly and then begin to fall off as the work tuoe fills with gas. As soon as this occurs open tap B. Adjust the gas flow to about 75 ml/min. 4 Start the furnace up and raise the temperature to 1000' C, holding it for two hours. Allow the temperature to fali to about 200C, then shut off the gas flow, take out bung A and withdraw the combustion boat. Place the boat in a dessicator, and reweigh it when cool. 5 Calculate the % weight loss as ignition loss. interpretation of Results Amphibole asbestos fibres have an ignition loss of 2 to 3% due to loss of of ignition Loss Test combined water, when the test is made in an inert atmosphere (nitrogen). In an oxidising atmosphere this loss of combined water is offset by a gain in weight of the fibre due to its oxidation. The oxidation process is completed only at temperatures above 900C, therefore the test temperature of 1000C must be adhered to. The net loss under oxidising conditions will generally be up to 0.5%. If the ignition loss test is made by conventional means, say in a covered crucible in a muffle furnace, there may be restricted access of air to the sample and a result will be obtained which may be intermediate between those found in inert atmosphere and pure oxidising conditions. A similar effect may be found if the sample is not out-gassed before making a test in an inert atmosphere. Results will only be repeatable when the conditions described in the method above are strictly observed. Chrysotile fibres have ignition losses of about 13% independently of the surrounding atmosphere, and at temperatures in excess of 800C. It must be emphasised that a statement of ignition loss of asbestos fibres must include the conditions of test. These should state: temperature, inert or oxidising atmosphere and duration of ignition temperature. 01 040 1307 3 i i \ L i o u r .C- zA',<i'zL4< Ac:c. -OSS and Extractable * a /* ^ 0 * 3 ^ I V I O' d 4 W* U W 52 The acid resistance of asbestos fibres, particularly blue asbestos, provides one of their most important chemical properties. As these fibres find use in chemical resistant plastic laminates and in battery boxes, a standard acid loss test is a prerequisite in determining the most suitable grade of fibre. A knowledge of the acid extractable metals calcium, magnesium, iron and manganese is aiso important, manganese being particularly so in relation to battery box manufacture. Equipment 1 2 3 4 The test is made under reflux using: A 500 ml round bottomed flask. A Liebig condenser fitted in the flask. A heated sand bath or electro-mantle to heat the flask and contents. An analytical balance, dessicator and drying oven (105C), Buchner flask, sintered glass crucibles (No 1 porosity). Method Either of two procedures may be adopted : 1 A standard battery acid test boiling the sample under reflux for one hour with 40% H-.SG* (SG 1.250). 2 Exhaustive tests in which samples from the test batch of fibre are refluxed for z hr. j hr, 1 hr, 2 hr, 4 hr and 8 hr periods. The types and concentrations of the acids used are at the discretion of the user. The technique for all these tests is identical: 1 Exactly 3 gm of dried fibre is placed in the flask with 150 ml of the required acid. It is advisable to add also a few large glass beads to minimise bumping when the test is commenced. Fit up the apparatus and bring the contents of the flask to the boil. The start of the test period is taken when boiling commences. 2 When the test period is over, the contents of the flask are filtered over a tared coarse sintered glass crucible (No 1 porosity), mounted over a Buchner filter flask. The fibres retained in the crucible are washed with distilled water, to remove all traces of acid. The filtrates are to be retained. 3 The crucible is dried at 105C and weighed back. Results The weight loss is then calculated as a % of the original weight taken. For a batten/ box fibre this % weight loss is the final test figure. When exhaustive tests on a fibre have been made, the observed weight losses are plotted on a graph against corresponding test periods. The graph shows both rate of weight loss and ultimate weight loss (or ultimate acid resistance). Notes 1 Exhaustive tests on fibres may be made with HCI, H-SO*, HNOj, CHjCOOH, H3PO4. and concentrations of these may be varied from 1% to 40% as required. For comparative purposes 20% HCI should be used as a basis, as this acid has the most destructive effect on asbestos fibres. 2 Concentrations: 20% HCI: Dilute 480 ml 'Analar' concentrated acid to 1 litre. 4C% H3SO4: Dilute 222 ml 'Analar' concentrated acid to 1 litre. Extractable Matter The filtrates from the acid loss test, which have been retained in the Buchner flask, ere transferraa to a 1 litre beaker, for quantitative examination of Ca ,V!g, Fe and Mn. Bromine water is added to oxidise any ferrous ions preseryyathe ferucxtateaijd tht. solution coiled down to 150 ml. ^ ^ vfxlf loUu A few grammes of NH.Ci are added to the solution and the ferric iron is then double precipitated with ammonium, hycroxice. The suspension is filtered hot and the filtrate collected in a standard flask and made up to 500 ml. This solution contains the Mg and Ca ions wnich ore determined volumetricaily with EDTA. The ferric hydroxide precipitate (after having been wasned with a 1% solution or containing a few crops of concentrated ammonium nydroxide- the washings being coded to the Ca/Mg solution) is transferred with the filter paper to a beaker containing dilute H^SO.*. This is boiled gently to dissolve up tne Fe~ and to disintegrate the filter paper. The macerated filter paper is filtered off and the solution made up to 250 ml in a standard flask ana the ferric iron determined volumetricaily with mercurous nitrate. Alternatively, after boiling and dilution, if the iron is present in suitable quantities^ then the ferric iron solution containing the filter paper suspension can be titrated in toto against mercurous nitrate. Manganese is determined (in cases where the extract does not contain HCI) by making the solution obtained after filtration of the fibre up to a known volume of 500 ml and pipetting off 100 ml for the Mn determination. The remaining 400 ml is then used for determining the Ca, Mg and Fe content as described above. To the 100 ml of solution sufficient phosphoric acid is added to just decolourise the iron salts, then one gram of potassium periodate is added and the solution heated to boiling - it is kept gently boiling for five minutes. After making up to a suitable volume it is determined colorimetricaily. With acid less tests carried out using HCI a more involved procedure is necessary, as all chloride ions must be removed as they will interfere with the Mn determination. The 100 ml portion is evaporated to dryness and a few cc of concentrated H2SCU added to the residue to remove ail chloride. The extract will fume vigorously, heating being continued until the H2SO4 has been reduced to at least half its volume to ensure that all chloride has been removed. The concentrated extract is then diluted and the manganese determined on this solution as before. 01 040 1310 01 040 1311 -r*\> j 3 ^ f MB w* **' '*>--' * O* ^ 'w1 4 \O^ %C* C"' -J ^M r^- . 9-1 A small asbestos testing laboratory, suitable for both routine and investigational work requires 500 to GOO sq ft or space, and should comprise the following sections. ' A dry testing section, containing the Quebec Standard Testing Machine, the Slaine Dyckerhoff (or similar) air permeability apparatus, a laboratory fibre mill, anc a fibre sorting bench; also P.otap Sieve Shaker (if required). Two weighing scales will be needed; a large pan scale, capacity up to 5 Kg, scale both in Kg and lb, with subdivisions to gm and oz, accuracy about 5 gm or oz, for use with the Canadian.Sox Test; a smail pan scale, capacity up to 200 gm accurate to 0.1 gm for use with the air permeability apparatus. This section should be adequately dust exhausted and if possible partitioned off from the rest of the laboratory. Dust exhaust hoods should be sited over the Quebec Standard Testing Machine, the fibre mill, the sorting bench, and the sieve shaker. 2 A wet-testing section, containing the McNett classifier, the reinforcing value test equipment, fiitration and wet volume testing equipment. Ail these will require water supplies and a large sink should be provided. A large oven, capacity about 3 cu ft fitted with four perforated metal shelves will be needed for drying McNett samples and test boards. Two weighing scales will be needed; a small pan scale, capacity up to 500 gm but accurate to 1 /10 gm for use with all tests except the McNett classifier; a laboratory balance, accurate to 1 /100 gm for use with the McNett classifier. 3 A bench for miscellaneous tests, including colour matching and length sorting. Glass beakers, measuring cylinders and large Petri dishes are all useful items for the visual examination of smaii samples of fibre in water. A microscope should be provided for the examination of asbestos fibres and asbestos-cement board. Probably the most useful type of instrument for this purpose is a stereoscopic microscope having several magnifications up to x 80. 4 Fibre storage shelves. These should allow for: a Storage of bulk samples for testing. b Storage of small enveiope or box samples of ail fibres testea, so that a permanent index of these may be built up. The estimated total cost of the test equipment for such a laboratory will be over 3,000, about he;: of which wiil be accounted for by the Quebec Standard Testing Machine and tne McNett classifier. Benches, storage shelves, dust exhaust equipment and services may account for a further 1,000, but as much of this wiil be built locally, as will some of tha test equipment, overall cost of the laboratory wiil vary somewhat from place to place. 01 040 1312 1 The Quebec Standard Asbestos Testing .Viachine Drawings cn.y: National Research Cour.c.l of Canada, Publication No NRC 3470, "Specifications ana Drawings for Quebec Standard Asbestos Testing Machine, Mode! No 2 1933'. Complete Machine: Lynn MacLeod Engineering Supplies Limited, Thetfora Minas, Quebec, Canada. 2 The Sauer McNett Classifier No 203A Bauer Brothers Company, Springfield, Ohio. H. E. Messmer Limited, 144c Offord Road, London N1, England. 3 The Suter-Webb Comb Sorter Alfred Suter Company, 200 Fifth Avenue, New York, USA. 4 The Blaine Dyckerhcff Air Permeability Apparatus Chemiscnes Laboratorium fur Toninoustrie, Stammhaus, Berlin (West), den Berlin-Reinickendorf 1, Kopenhagener Strasse 60-74c, West Germany. 5 The P.igden Apparatus Griffin and George Limited, Ealing Road, Alperton, Middlesex, England. Cape Asbestos Fibres Limited, 114 Park Street, London W1, England. 6 Universal Air Permeability Cells Cape Asbestos Fibres Limited, 114 Park Street, London W1, England. 7 Vacuum Pumps Mono Pumps Limited, Mono House, Sekforde Street, London EC1, England. Watson Marlow Air Pumps Company, Marlow, Buckingnamshire, England. 8 inverter Cape Asbestos Fibres Limited, 114 Park Street, London W1, England. 9 -Te.nsometers Tensometer Limited, 31 Morland Road, Croydon, Surrey. Zwick Q Company KG, Einsingen Bei Ulm-Donau, Germany. 10 Laboratory Mill Ludwig Pallmann Limited, Zweibrucken Pfals, Germany. 11 Rotap Sieve Shaker International Combustion Products Limited, 19 Woburn Place, London WC1, England. 01 040 1313 -\>m ie CHRYSOT \ LE. ASBESTOS 01 040 1314 SECTION- 4- MOODV FIBRE. FLUFFED 01 040 1315 PART II CHRYSOTILE ASBESTOS SECTION 4 -- MOODY FIBRE FLUFFER The Moody Fibre Fluffer re-opens pressure packed, asbestos fibre, which now arrives at Berlin in paper bags and which is chrysotile asbestos. However, Cape is installing some bagging equipment on a trial basis for pressure packing amosite in the future. All of the grades from shorts in 7D grade up are restored to their fluffy pre-packaged condition. Whether this is done as efficiently and to this maximum degree by wet milling through the Bauer MU is probmatical? At 15 ton capacity this is sufficiently great to allow fitting into the Kaylo batch mixing operation. The merit of such a piece of equipment opening of chrysotile dry can be measured by the result of opening chrysotile through the Pallman Mill and whether or not settings for openings have to be changed on the Pallman between amosite and chrysotile asbestos fibres. 01 040 1316 5 l Partial list of ujort Unitod Butts A<C4>rO{ Co. Inc. American 8rot American Smelling Armstrong Cork Co. * Agio Specialties Baitenleld Grease Ouret Plaitict Eaton Mfo. Co. Fiinikoie Co. Gritxiy Mfg. D*v. Henry, V/. W. Co. Hooter Chemical Co. Inland Mtg. Oi* Jolms.Manviila Uintie Air Products' Mortliali-Eclipsa Oiv. ol Bcndit Notional Brick Co. Notional Gypsum NicolOt Industries, Hamilton, Ohio Nieolel Industries, Norristown, Pa. Philip Corey Co. Snpradur Mfg, Corp. Thcrinoid Co. Union Asbestos tJ. S; Gypsum Worliibestoi | | I | i' . ' I MOODY Fibre FSuffer re-opens Pressure Packed Asbestos Fibre ... all grades of pressure packed asbestos from shorts 7-R to spinning fibre 3-R restored to pre-packaged fluffy condition ---- free from lumps and mats. Compact, simple to operate --fits into any production line. Up to 15 ton capacity per hour. Co node AsItesJot Coro, Aibcitonos Corp. Atlos Asbestos Conodinn Johns* Manvijle Cossior1 Asbestos Husky Oil Loke Asbestos Elsew.Hnre BcroUBrcmtoelag Kg,, West Germany Evfrearinlucbod. I I lelienic Building Materials, Greece Industrie do Asbestos Dominican Republic ' Israel Brake Lining, Israel i. 0. Jones, India Pacmnc Machinery, Philippines Turner Bros., England Full d.laili and lit.fotvr. an r.qu*d F.O. SOX to. MOUNT ROYAL F.O. ' MONTREAL It, OUE. K3A""K![rLnJ EAOOE3V DIVISION CANADIAN BOWL-MOR COMPANY LTD. H..d Offic. 4 FI,at: T.rr.bona*, F.Q. Br.acti OHtcai: Moat,,,l 1 TonMa "ASBESTOS" -- October 1062 Page 10 !. i.- i : f 01 Q40 SECTION- 5 MILLING ASBESTOS 01 040 1318 SECTION 5 -- MILLING ASBESTOS This is an article on the preparation of chrysotile asbestos from the mine to the shipping bag. It was written by J. C. Kelleher, of the Johns-Manville Corporation, who was the General Sales Manager of their Asbestos Fibers Divi sion operating their Thetford, Quebec mines. At one time the Kaylo Division bought all of their chrysotile asbestos from this source. The switch to other producers of chrysotile asbestos came about several years ago, when the J-M chrysotile was discovered to contain the highest chloride content. This was inconsistent to our attempt to lower the chloride content of all Kaylo end products. The terms 'crudy' and 'open' are defined regarding the type of asbestos bundles, where the former is coarse or relatively thick and as 'open' when the fibers are finely divided. Packaging in compressed paper bags has been adopted 100 percent for grades used in manufacture of calcium silicate insulation, since this article was written. 01 040 1319 BMrrcRmnotr MILLING ASBESTOS Crushing and Screening ... 3 Clean in g and Grading .... 7 Equipment.................................................... 12 Uses of Specific Grades 15 Reprinted from "asbestos" Philadelphia, Pa. Price - 25c per copy i i 01 04(1 1320 If fi'f T~ *Yi ~ MILLING ASBESTOS By J. C. Kelleher1 Asbestos* owes its place of importance in industry to a unique combination of qualities. It is the only known material which combines the fibrous characteristics of an organic material, such as wool or cotton, with the resistance to heat, wear and time, of a mineral, such as granite. Production ot' asbestos requires two majorsteps, mining and milling. Mining consists of removing the fibre bearing ore from the mine and delivering it to the mill, and is therefore like many other mining or quarrying operations. Milling covers the steps necessary in removing tiie fibre from the ore, and the cleaning, grading, and bagging of it for shipment. Asbestos milling is like no other type of mineral recovery and therefore requires special machinery and mill design. M'e shall discuss the milling process,principally as it refers to the production of Chrysotile fibre, the major asbestos of use in industry. As much as 480,000 tons of fibre have been milled in Canada in a single year. To understand the milling process, it is necessary to visualize the objective and the characteristics of the ore. Since the value of asbestos fibre depends largely on the fibre length, every effort is made to prevent reduction of length, that is, the cutting of the fibre during the milling operation. This objective is carried out in the design and operation of all mill equipment. The fibre itself is an integral part of the rock or ore. It has the same density and chemical make-up and is of equal hardness. Fibre occurs in veins of varying widths, the width of the vein corresponding to the length of the fibre. Veins may vary from two inches in width down to 1/32 of an inch. The average width of fibre veins is well below 1/2 inch. The direction of fibre length is at right angles to the plane of the vein. Fibre in mill rock usually * Manager, Asbestos Fibre Distributors. Division ot JobnsManvlUe Sales Corporation. I ! t ; j . | ; < ' j | | ! : ! I j i i j j j j i 01 040 1321 i runs fr"iu three to ten percent of the total rock fed to the mill. CRUSHlNO AND SCUEENLNU Briefly .-Uitted, the entire milling operation consists of extracting the fibre from the rock by repetitive erushings of the ore, at each crushing removing as much free fibre as possible by air-suctiou or aspiration and screen ing the freed fibre, to drop out sand, rock and dust. The standard dry separation of fibre from rock is based on A typical sample of rich ore. showing cross vein fibre formation the principal that fibre which has been partially opened or fiberized in crushers is lighter in density and offers more resistance to air flow than unopened fibre or rock, and can be lifted by a light air current which will not lift the rock particles. Russian mines have taken advan tage of this difference in density of open fibre and rock, and separate them by letting the material flow by gravity down an inclined chute. The heavier rock parti cles are thrown farther from the end of the chute than the lighter fibre, thus obtaining a rough classification. Various combinations of equipment have been in stalled over the years to obtain a combination of high quality fibre and economic operation. The accompanying chart (see page 4) shows the sequence of major opera tions common to practically all mills. It does not purport to show the full complexity of a complete mill flow line. Rock or ore from the mine is fed to primary crushers from a storage bin large enough to assure ample feed for --8 -- 01 040 1322 the mill. The primary crusher. Usually nC thy jaw Type, is capable of taking rock up to 48 inches in size, weighing up to a ton or move. The jaws are set to crush to ap proximately six inches in width at discharge. Crushed rock is carried to trommel screens--large revolving cylinders with various size openings, which MILL ORE PRIMARY CRUSHING (Rockup to 48") TROMMEL SCREENS OVERS THROUGHS SECONDARY CRUSHING separate the rock too large to be fed to the dryers. The larger rock, over four inch es. is fed to a secon dary stage of crush DRYERS MILL ROCK STORAGE THIRD STAGE CRUSHING SHAKING SCREENS-OVERHEAD SUCTION FIBRE OVERS THROUGHS CLEANING CRUSHING GRAOING SHAKINGSCREENS-OVERHEAD SUCTION ing. usually a gyra tory or cone type crusher, before join ing the screened rock and passing on con veyor belts to dryer bins. At this point in the mill flow the rock FIBRE OVERS THROUGHS CLEANING FIBERIZERS GRADING SHAKING SCREENS-OVERHEAD SUCTION FIBRE OVERS THROUGHS CLEANING FIBERIZERS TAILINGS GRADING SHAKING SCREENS-OVERHEAD SUCTION Tufticuf mitt flniv aheet Shoving vs** iifinf opera Hon*. must be dried, as. de pending on the sea son and weather, the mill ore contains varying amounts of moisture: snow and iee often enter the mill with the ore in w inter. Efficient milling operation reipiires eompletelv dry m-e. Drying is accomplished in cither stack or rotary dryers varying from -TO to (i() feet in length and "> to 7 feet in diameter. In either ease the rock is cascaded thru a current of hot air generated by oil or coal furnaces, the rock being in contact with the heated air from a few seconds to twelve minutes, depending on the amount of moisture, the type of dryer, the temperature of the dryer, and the rate of feed. Drying temperatures range from 200 deg. F. to KKK) deg. F. --4-- 01 040 1323 M. Uim-U t'rnin tin- i' conveyed to a large, dry, rock storage room. nr Wins where the latent heat in the ore completes the drying process. T!ie storage bins act as a reservoir of reek to assure a constant tiow of mill feed. The necessity of tremendous rook storage capacity is readily apparent, when we consider that mills consume as hi>:h as :jO(l tons of ore per hour or WHIG tons in a 20 hour day. A large dry storage of ore eliminates variations in mill feed due to changes in the ore from hour to hour. Many days' supply is piled in layers, which tends to average the mass when a supply is withdrawn. Ore from the storage bins running up to two to three inches in dze is put thru a third stage of crushing in ci ushers of the gyratory or cone type which further crush the rock and free the fibre. The product of the third crushing stage is fed to heavy shaking serpens equipped with powerful air sue* tiun hoods, where the fivst step of fibre removal occurs. The 'halving or humping action of the screens, obtained by tin eccentric drive mechanism separates the light, partially opened fibre from the heavier rock and sand particles. The ore and fibre mass passes down the screen aided by the shaking morion, and under the suction hood where the free fibre is lifted by air suction and the rock passes over the end of the screen. The undersize material passes thru the screen and to fiberi/.ers for further treat ment. The freed fibre is fed to duplex 'two level) shak ing screens, equipped with suction hoods, where it is separated into long, medium aud short fractions. The long tihre remaining on the top screen is picked up by suction and delivered to a fibre collector. The medium length fibre from the lower screen is fed to a single deck slinking.screen where it in turn is picked up by suction and delivered to a collector for its particular grade or length. The short fibre passing the lower screen is con veyed to bins for further grinding and cleaning for special short grades. The rock, passing over the ends of the heavy shaking screens,. is carried to a fourth and last 5 stage of crushing, where it is reduced to approximately one-quarter inch in size and again passed over shaking screens with suction for fibre removal. The fibre is dis charged to collectors for the various lengths of fibre. The rock, which remains after the fourth stage of crush ing, i. e., material passing over the ends of the screens, and the undersize from the first or rock screening opera tions, are fed to fiberizers, not crushers, for further separation. Here we should point out the difference between a crushing and fiberizing action. The crushers break the rock by pinching or compressing it. The fiberizer, which consists of high speed hammers in motion, breaks the rock by blow or impact. The falling rock is struck by re volving hammers with a top speed of 10,000 feet per min ute. In eitiier case, fibre is released. The impact break is more severe and is not usually used until the longer, more valuable fibres have been freed. The product of the fiberizers, like that from the crushing operations, is fed to shaking screens where again the fibre is collected by suction and carried to fibre collectors for different lengths of fibre. The steps of fiberizing, screening and suction are continuous thruout the complete milling process, and the three operations together represent the major elements of asbestos milling. At each suction-screening operation, part of the fibre is collected and part passes on for collection from subsequent screens. The number of screening and suc tion operations necessary can be visualized when we realize that a normal sized mill may contain hundreds of screens housed in large five or six story mill buildings. The complexity of the detailed flow of material thru the complete mill, including the many repetitive operations, is entirely too involved for an ordinary discussion. Many variations in a flow sheet are necessary due to the wide variations in the ore itself. We have referred several times to fibre being separated from the rock on shaking screens by means of suction hoods. The accompanying --6-- Shakutg Screen with auction hood -Vote jibre jfe<: ore after it imssra under hood <'i.uri,.>r The K<iIhtii<I Co. picture clearly .shows <1 suction hood over ;i shaking screen, it is best described a an oversize vacuum cleauer, which sucks up the light fibre and some dust and rejects the heavier pieces of unopened fibre and rock. The undersize material or waste from the screening operations, when it has been considered sufficiently free of fibre, is conveyed to tailing dumps. Since the tailings or rejected rock equals !>()',' of the original ore fed to <he mill, waste dumps loom largo in the landscape of the asbestos mining country. In recent years the recovery of short fibres included in the tailings and the potential recovery of the high metallic content, have focused at tention on the value of these mountains of fine gravel. Cf-KANTN'li AND (iUADlXC No discussion of milling asbestos should omit men tion of the disposition of the vast volume of fines, i. e.. extremely fine, short fibres and pulverized rock created in the treatment of Ihe ore. The many millions of cubic feel of air being handled hourly by the air collecting sys tem, are heavily laden with fines. This must be deposited without being ejected to the atmosphere, to the detri ment of the surrounding community. This objective is accomplished by discharging the fan exhausts into a vast room or chamber known as a float shed. Tn thi- space 01 040 1330 I the velocity of the air is dissipated and the due material settles out. The bin, or shed, is divided into a number of compartments at varying distances from the air inlet. Each compartment collects floats of different ranges of particle size. Asbestos floats, as sold, are a product of one or more of the float bins. The finest particles are prevented from passing out to the atmosphere by such methods as electric precipitation or passage thru canvas filtering bags. We have considered the removal of fibre from the ore and explained that the suction fans discharged the fibre to collectors for each fibre length grade; it is now necessary to clean, grade, and bag the fibre for shipment. The fibre collector, a large sheet metal conical cylin der, performs the first step in the cleaning operation. The current of air which carries the fibre and rock dust to the collector, deposits the heavier fibre and carries the dust laden air to the float shed described above. Further cleaning consists of screening the opened fibre over light screens. Here dust and rock falls thru toe screen meshes and the fibre is discharged off the end of the screen by suction. Well opened fibre does not screen readily; that is, it tends to cling together, permitting the use of coarse screens which drop out the rock without loss of fibre. Several repetitions of the screening operation may be performed to obtain proper cleaning. A final cleaning operation consists of dropping fibre thru a cyclone or air selector, similar in design to a fibre collector, the heavier rock and unopened fibre falling vertically thru and the lighter fibre being drawn off the side of the collector by suction and again deposited in collectors. The sequence of the various cleaning operations, screening and air selection, and their tie in with the collecting and grading operations, vary in different mills and even within a given mill depending on the type and grade of fibre being produced. We have merely described the steps of cleaning as tho they occurred progressively, as well they might, in a simple mill layout. Grading fibre means classifying it according to I \ ! 'I ! j | j i | f j j j j j I *1 r; ' ! ! j j j . 01 040 1327 Typical Courtevv tj,uadiaa J-M Co. Ltd. of milled fibres in mayor group grading?. length. The value of a given type of fibre depends chief ly on its length. There are five major classifications ac cording to length, namely, and in descending order of length they are: Spinning or Group 3, Shingle or Group 4, Paper or Group 5, Stucco-plaster or Group 6, and Shorts or Group 7. In each Group are a number of grades or subdivisions, all meeting a standard screen test for length. An average mill produces at least twenty-four separate grades. Obtaining these grades in a mill is accomplished in specially designed graders. They are usually long rotary screens covered with screen wire of various size mesh. Fibre is fed into one end of the slowly turning screen, in which revolving paddles force the fibre thru the screen openings. Short fibres pass thru the fine mesh at the enter ing end, longer fibre passes thru larger mesh in the second half of the screen length, and the longest materials pass over the end of the screens. Grades are obtained by experienced operators by combining proper proportions of material from two or more of the various screen sizes. Several grades may be made at the same time on one grader by directing the flow of varying proportions of the different length pro ducts of the grader into appropriate collectors. Careful grading calls for close cooperation between --9-- 01 040 132$ __ the operating men and the testing men or inspectors, since, depending on the results of frequent tests, the flow of material from the graders can be adjusted to avoid off-grade fibre. Graded fibre is conveyed to bins above the bagging room from which it passes by gravity thru metal chutes to bagging machines. These machines may be semi-auto matic or manually operated. They load the fibre into burlap or jute bags of one hundred pounds net weight, compressing the fibre to reduce the bulk in shipping. Ail bags are sewn by hand or with portable stitchers before being loaded into freight cars or sent to stock. Many special grades are made by variations in the regular mill flow line. Large quantities of short fibres are produced by special grinding, screening, and cleaning of the fine undersize products of many of the screening operations. Highly cleaned grades of longer fibres are produced by repeated passages thru series of air select ors, which drop out all heavy particles and remove a major part of the fine dust. "When desired, partially opened or Crudy fibres are produced by eliminating the high speed impact fiberizing operations. Where the terms "crudy" and "open" are used in referring to fibre, it can be generally understood that crudy or partially opened fibre is a product of crushing, whereas open fibre is the result of a fiberizing operation. Asbestos fibre is unique in that it has no definite fibre diameter like hair or cotton. It can be subdivided indefinitely within the limits of the ordinary microscope. Fibres one-eightieth the thickness of a human hair have been measured. Thus, each fibre is in reality a bundle of finer fibres. An opening process is one which tends to subdivide the fibre bundles. Fibre is spoken of as "Crudy" when the fibre bundles are coarse, or relatively thick, and as "Open" when the fibres are finely divided. Highly opened fibres are obtained for special require ments by adding an extra step of fiberization in specially designed hammer mills. Blending, or mixing, permits the production of fibres f ! i i x not obtainable in regular mill operations. By this method definite proportions of coarse or fine fibre, short or med ium lengths, can be obtained and such features as filtra tion rate, wet volume, covering capacity, adhesion, ab sorption, etc., can be controlled. While crude fibres, that is No. 1 and 2 Crudes, are not products of the milling process as are the milled fibres in Groups 3 to 7, they are the form in which fibre is gen erally pictured. Crudes are chunks of fibre which have been separated from the rock or ore, and have consider able fibre length. No. 1 Crude runs from % inches up, and No. 2 includes fibres from % to % inches. Shorter Crudes are classified as No. 3 or Sundry. The Crude fibre is cobbed or chipped from the broken ore in the quarry, cleaned and graded in the cobbing shed and weighed and bagged for shipment. Asbestos is evaluated and sold by grades, as estab lished by the Quebec Government and classified in the Standard Quebec Asbestos Classification. The detailed screen specification of all grades and the methods of test have been widely published1, and will not be repeated here. An important step in Asbestos milling, however, is the sampling and testing of fibre according to the Standard Quebec Classification, prior to storing or shipping. Before fibre bags are closed, composite samples of each shipment are taken by inspectors and tested. The usual method of sampling is to take a "grab" sample from well down in each bag. The samples from each ten or twenty bags are combined to make a test lot. These tests represent a fair average of each car. The fibre is well mixed, and one pound is screened in the standard testing machine. Lots which meet the test requirements are tagged and sewed for transfer to stock or to cars. Lots which fail to pass, are sent back to the mill for regrading. In the case of special grades 1 See reprint "Canadian Chrysolite Asbestos Classification" obtain able from "asbestos", 17 FI., Inquirer Bldg., Phlla. 30, Pa^ for 25c. prepared by additional operations of mixing or extra fiberizing or cleaning, special tests are often made to check them against a particular requirement. EQUIPMENT For the sake of clarity, the major steps in Asbestos milling and their relation to one another have been describ ed with a minimum reference to equipment and buildings. The magnitude and complexity of the mills in which the operations occur are a matter of comment and observation by visitors. An asbestos mill is generally spoken of and guaged in terms of the number of tons of ore per hour which it is capable of processing. Mills vary in size from 50 tons to 300 tons of rock per hour, or from 1.000 to 6,000 tons per day. N. F. B. Photo .1 slustos milts m Hit I'nmu/inn Johns-Maii rille Corporation, s ho ic ing part of the mill buildings.--dust rrmoriil. ilotcn comers, tail ings. conn-gar. mul limn Ion loading bin. Mill buildings vary in size and construction. In general they are all of multi-storv, fireproof construction. The multi-storv design is followed to take advantage as far as possible, of gravity flow of rock and fibre, material passing from floor to floor by gravity and being returned to the upper floors by conveyor, or suction fans. The major items of equipment are: crushers, dryers, conveyors, fiberizers. shaking screens, suction hoods, blow ers, air collectors, graders, and bagging equipment, with -- 12 -- 01 040 necessary power accessories, ductwork, and storage facilities. The number of units of each type equipment in any mill depends on the tons per hour of ore to be handled, or capacity of the mill. As far as practical, all equipment is made of metal, wood being eliminated to prevent its getting into the bag ged fibre. Wooden housings for screw conveyors and wood chutes are the most troublesome and prevalent sources of contamination. Rock crushers are usually of gyratory or jaw. type and descend in size from 6" discharge to !4"- Fiberizers may vary in design. The general principle is the cracking or disintegration of rock by high speed impact. A horizontal or vertical shaft carrying a row of swinging hammers rotates in a cylindrical metal shell six to eight feet in length and 24 to 30 inches in diameter. The rock enters at one end and is discharged from the opposite end. The shell carries rows of stationary hammers spaced alternately to the swinging hammers. During the passage the rock is subjected to blows from the hammers rotating up to 2000 RPM. The many screens in a mill are usually of a shaking, rotary or gyrating type. To be effective, the screens must carry only thin layers of material to permit efficient separation of rock and fibre. Thus many thousands of square feet of screen area are necessary to accomodate the mill flow. Shaking screens are equipped with suction hoods where fibre is to be removed to collectors. Where a simple screening or cleaning operation occurs in a series of screens, many of them do not require the suction hoods. Screens may vary from three to six feet in width and eight to eighteen feet in length. Fibre collectors of large aggregate volume are required to hold the accumulations of fibre in the different stages of milling. The collectors are galvanized iron cylinders, from four to eight feet in diameter, the bottom half conical. Inlet and outlet ducts in the upper half of the collector bring in the fibre and discharge the dust laden air. The fibre which settles, because of its weight, is collected and drawn off from a gate in the cone shaped bottom. -- 13 -- I i I i t 1 j : 1 j j i j . ! ( j i ; j ' | r 01 040 1331 DIAGRAMATIC SECTION OF CRUSHING UNITS USED IN MILLING ASBESTOS ORE 1 i* l t The crushing process is accomplished thru reduction by pressure between a vibrating and a stationary jaw with a subsequent freeing movement, at which time the ms* terial settles by gravity until caught and subjected to further pressure and then released. - orunao DX3C8UBS GYRATORY CRUSHER The ore enters the top and falls on the gyrating head and is crushed between the head and the bowl by the ec* centric rotation of the head. The discharge may be set to the size crushing desired. -- 14 -- I l i el 040.1332 Grading and bagging equipment has previously been briefly described. USES Ml'' SPECIFIC GRADES "We have followed fibre production thru the crushing, fiberizing, collecting, cleaning, grading, inspection and bagging operations. In closing, a brief discussion of its major uses may be of interest. The uses of asbestos are as varied as the physical make-up of the fibre itself. Eliminating crudes, Canadian milled asbestos fibre varies from a fine powder selling at $15 to $20 per ton to a long, silky fibre at over $200 per ton. The uses of asbestos can most clearly be explained by showing the purposes which the fibres serve rather than listing the products in which they are used. As a reinforcing filler asbestos fibres are used in a wide variety of ma> terials, ranging from plastic molding to asbestos cement shingles and molded brake linings. The major uses indnde the following: Long fibres are used as a textile fibre; are felted to make long fibre paper; as a filtration medium; and as a reinforcing filler in asbestos-cement products where great strength is required. Medium length fibres which include the short spinning, the shingle and the paper grades, are used as a rein forcing filler in asbestos-cement products; as the major component of asbestos paper and millboard; aa a reinforcing and binding agent in magnesia and other molded insulation; are felted with cellulose fibre for filtration sheets and pads; as a reinforcing filler in molded friction blocks and brake linings; and as an insulating mass in sprayed insulations. Short Fibres and Floats are used as a self binding in sulating cement; as a filler and reinforcement in all types of asphalt paints, putties and compounds; as a filler and reinforcement in plaster and stucco; as a filler and rein forcement in asphalt tile flooring; and aa an insulating -- 15 -- ! i ! 1 ; ! ' j ' j j j : ! ] 01 040: 1333 space filler. Floats and Shorts also find use as a mineral reinforcing filler in plastics; as a filler in lubricating grease; and as a silicic flux in the welding industry. The unique combination of qualities which make asbestos alone the suitable material for these many uses, is its fibrous form (like cotton or wool) and its inorganic stone-like composition. It is fibrous, strong, will not burn. and forever resists weather. It has the workability of an animal or vegetable mineral with the fire and weather re sistance of a granite block. j j ; j Printed In tile United St*lee luuarr 194t 1 I i J it 01 040 1334 SECTION- 6 RECOVERV OF RAW ASBESTOS 01 040 1335 SECTION 6 -- RECOVERY OF RAW ASBESTOS Roland Starkey's write up of raw asbestos recovery is of processing the African chrysotile. Turner and NewaU, Ltd. are insulation manufacturers in Britain, the chief competitor of Cape Asbestos, whose insulation runs from 85 psrcent magnesia to calcium silicates in the high temperature field. At the time this article was written some hand pickers were used, because of cheap labor, as against the completely mechanized milling of the Canadian Mines. The African chrysotile tonnage is considerably below the Canadian annual production and their shipping cost to the United States offsets their lower labor and the Canadian mechanization reduces milling costs of their fiber so that the North American chrysotile dominates the large percentage of the Unites States market. 01 040 1336 RECOVERY OF RAY/ ASBESTOS At The Havelock Mine I I By Boland Starkey M. Inst. M. M. Confuting Engineer, and Staff of African Associated Mines, Limited ' v. i! i j Reprinted from May 1947 "AsnEaTOS"i i Philadelphia, Pa. 01 040 1337 i RECOVERY OF RAW ASBESTOS Methods Used at Havelock Mine By Roland Starkey .11. Inst. M. M. Consulting Engineer, and Staff of African Associated Mines, Limited Production of chrysotile asbestos from the Havelock Mine began in June, 1939 and the milling methods adopted were the result of a considerable amount of experience and research by technicians of Turner & Newall, Ltd., both from their mines in Africa and from their factories in the United Kingdom. The Havelock Mine is situated in Swaziland a few miles over the Eastern border of the Transvaal. It is owned by New Amianthus Mines, Ltd., a subsidiary company of Turner & Newall, Ltd., of Rochdale, England. About one quarter of the ore delivered to the mill bins is derived from opencast quarrying operations and the re maining three quarters is broken in underground sub-level caving stopes. The first operation in the mill is of sizing and hand soi'ting. The rate of flow from the mill bins is 110 tons per hour and a rotating ring grizzley gives a 4-4 inch product; the "throughs" pass to trommels clad with steel punchedplate with circular holes of 2Vi inch diameter. Fibre near ing rock present in the +4 inch, and --1 inch 4-2% inch products, is picked off sorting conveyor belts by hand and the remaining barren waste rock is disposed of forthwith via waste, bin and dump haulage. This sorting operation yields a product known as Hand Cobbed Fibre constituting approximately 3% of the original feed; the coarse waste discard to dump amounts to 50%. The --2% inch product from trommelling contains moisture varying from 4% to a maximum of 33%, the average content being from 5% to 9%, and before further treatment can take place it is necessary to arrange to dry Page 1 i ; I i [ i j ; > 1 ; j j i 01 040 1338 this material. A type of tower dryer has been evolved, de signed to remove excess moisture without subjecting the asbestos to severe overheating or to undue mechanical at trition, both of winch would tend to destroy the delicate fibres. The tower dryer is essentially a vertical shell 40 feet high and 6 feet in diameter containing a system of baffles. Tlie moist ore showers down the dryer from top to bottom against the flow of hot furnace gases from a ther mostatically-controlled, automatic coal-fired stoker. The contained moisture in the discharge is approximately 2 to 3% and the temperature 180* F. A further trammelling process now separates the --Vo inch element of the dried material, the -r% inch --2V> inch element being presented in a uniform stream to vacuum air separating nozzles causing the loose fibre to be removed and deposited in a form of cyclone settler. The loose fibre recovered at this stage amounts to 2% of the original feed, while the --Vc inch material constitutes 22%. This leaves 23% of the original feed in the form of +Vs inch --2V} inch material, which is reduced to a 3 ft. short head Symons cone crusher. The loose fibre just referred to and the hand cobbed fibre previously noted receive separate treatment in order to preserve the long fibres present in the original ore. Drying of these two materials is completed in a steam dryer consisting of successive floors of pivot able steel plates along which steam pipes are conducted. The drying takes place on these floors, the material being passed from one floor to the next below at appropriate in tervals of time, a thoro turning over being effected at each transfer. From this point onwards the fibre recovery process consists essentially of a series of stage crushings followed by screening, and vacuum air separation of the released fibre. The initial reduction of the lumps of hand cobbed fibre is by means of a 16' x 10" jaw crusher and subse quent crushings are in pan rolls. This crushing machine Page 2 ! I comprises two edge runners revolving in ;m annular dished ; pan which rotates in a horizontal plane. The crushing takes j place between the edge runners, which together weigh 4000 . pounds, and the pan which rotates at 35 r. p. m.. the crushed material being discharged by means of a suitably arranged scraper. This type of crusher has been found to be very effective in separating fibre from containing rock without damaging the fibre down to limiting particle sizes of from .05 inch to .10 inch. The screening apparatus eon1 sists of inclined trommels of 3 feet diameter and 7'6" ] length, clad with wire screening cloth, the clear aperture j being reduced at each successive crushing stage. The free j fibre in the end discharge of these trommels passes over a j reciprocating light sheet metal table to a revolving screen, j At an appropriate distance, to effect separation of loose j fibre from rock and grit, is located the usual vacuum nozzle 1 thru which the fibre is lifted and subsequently deposited j in cyclone settlers of the centrifugal type. Pan rolls crush- iug, screening, and air separation process is applied also j to the --inch material and the crushed product from the j Symons cone crusher. ! As a result of these processes two types of material are I segregated, (a) fibrous products from cyclone settlers, i known as concentrates, and (b) sized gritty materials from 0.10 inch to 0.03 inch particles size, some of which are sent j to waste dump and the remainder have sufficient fibre conj tent to warrant further milling. i | Dealing first with the concentrates, which are only : roughly classified in respect of average fibre length and ; which contain a proportion of fine dust, it is necessary to j provide a screening (trommelling) plant in which there is i a much more searching classification into fibre length 1 groups and a practically complete elimination of fine dust The result is classified fibre in four grades. The next pro cess has a two-fold object, (a) to eliminate fractures in the individual strands of fibre, and (b) to eliminate the hard I bundles or faggots of fibre aggregates. The former purpose iI ' Page 3 i | \ !, : * j > ! ! * I ; [ 1 ! i ! \ j | j ! : ! ;| \ 01 040 1340 Vs t> JTV ensures that the marketable product shall have true fibre lengths between predetermined limits and the latter secures a product of uniform texture. Previous attempts to achieve these aims were generally incompletely successful because of the difficulty in providing a selective treatment whereby fibres already opened up and free from fractures were not subjected to further treatment tending to destroy the fibre altogether. The principle of the machine now in use involves two elements, first an absolutely uniform feed at a predetermined rate, and secondly, introduction of this uniform layer of fibre into a swiftly moving air stream which passes thru a series of streamlined chambers in each of which revolves a horizontal shaft at high speed. The shafts are provided with a large number of beater arms, VI* inch in diameter, radially thru the shaft and projecting about 4V-; inches on each side of the shaft. The direction of rotation of the shaft is opposed to the flow of the fibreair stream. Fibre particles impinge upon these rods and the force of the blow is naturally proportional to the mass of the fibre aggregate. The light elements of opened fibre pass on unmolested, whereas the more compact bundles re ceive sharp blows which open them and at the same time break down fractured elements into true unfractured strands of fibre. After passage thru these conditioning ma chines the asbestos is removed from the air stream in the usual cyclone settler and passes thru trommels clad with the appropriate screening to eliminate short length fibre resulting from the conditioning process just described. The discharge from the trommels (plus product) is bagged in 10 ounce hessian bags containing 125 lbs. net asbestos weight under registered marks HVL/2 (spinning grade), HVL/3, 4 and 5 (shingle grades). In the preliminary stages noted above, mention was made of gritty elements containing sufficient fibre to justify further treatment. Recovery from these materials is effected in a type of conditioning machine in which the rate of flow is regulated to achieve separation of fibre Page h I l I > i 1 f ! .| I 01 040 1341 --riMMrSj from adhering waste rock particles--a concentrate results which is incorporated in the flow in the same way as eoncentrates from other sources. Finer elements still--down to 0.03 inch particle size-- are subjected to a screening process in which a gyratory action is imparted to tlie horizontal screening surface giving selective treatment to the fibrous elements, opening them up and enabling the vacuum separating action to be come operative. The limit to which the ultimate fibre re covery can be pursued is, of course, an economic one in which factors of cost of crushing and treatment have to be offset against net revenue from the salable product after making allowances for transport charges to the customer. The rate of marketable asbestos production is approzi-. mately 26,000 tons per annum. | J j I j ! i i | ; [ This article is a companion (or supplement) to Mill- ing Asbestos by J. C. ICelleher, which was published in "asbestos" during 1945 and is also available in reprint form (at 25c per copy): i! I i I ! j ! Printed In U. S. A. s' Price ^lhc per copy i ! Page S I l *i rt i i ir . ! \ t i :i 01 040 1342 SECTION- 7 CANADIAN CHRYSOTILE. ASBESTOS CLASSIFICATION 01 040 1343 SECTION 7 -- CANADIAN CHRYSOTILE ASBESTOS CLASSIFICATION Explained in this section are the lists of standard grades of Canadian asbestos mines products as supervised by the Minister of Mines of Quebec province, with a guaranteed minimum shipping test of the grades. An explanation of the Quebec Asbestos Mining Association is included, as well as its screen sizes and operation. 01 040 1344 *-t. '?"*fir--v*r. j* January 1, 1949 CANADIAN CHRYSOTILE ASBESTOS CLASSIFICATION I (List of Standard Grades set up by the Committee on Uniform Classification and Grading of Asbestos Mines Products. This committee was formed in 1931 at the in stigation of the Minister of Mines of the Province of Quebec, and the list of grades has been revised from time to time. Latest revision December 1942) The asbestos mines products are divided into two classes: "Crude Asbestos" and "Milled Asbestos," respec tively, defined as follows: ii "Crude Asbestos" consists of the hand-selected crossvein material essentially in its native or unfiberized form. "Milled Asbestos" consists of ail grades produced by mechanical treatment of asbestos ore. i "Crude Asbestos" and "Milled Asbestos" are sub divided into groups designated and defined below. i Classification of the "Milled Asbestos" grades, in \ groups Nos. 3 to 7, inclusive, unless, otherwise specified is based on the Quebec Standard Testing Machine (see illus ! tration). "Shipping Test" is .the average for each carload or i i smaller shipment, of tests of representative samples taken at the time of shipping. "Guaranteed Minimum Shipping Test" is that below which the actual shipping test shall not fall. Group No. 1 Crude No. X Consists basically of crude % inch staple and longer ,Group No. 2 Crude No. 2 Consists basically ot crude % inch "Spi staple up to % inch . "Crude Rux-of-Mine Cbuoe8 Su.vdst Consists basically of unsorted crudes Consists of crudes other than above specified Group No. 3 Standard Deli(nation of Gradaa 3F Guaranteed Minimum Shlpplnf Teat 7 -- 7 -- 1.5-- 0.5 i 3K 3R i 3T ii* 3Z 4 --7 -- 4 -- 1 2 --8 -- 4 -- 2 1 --9 -- 4 -- 2 0 --8 -- 6 -- 2 I V. I 01 040 1345 ' ir*Mndli4, AtPWr tot iF-frh*Mwirisii Standard Designation of Grades Group No. 4 4H 4K 4M 4R 4T 4Z Guaranteed Minimum Shipping Test 0 --a -- 8 --3 0 --4 --9--3 0 0 -- __ 4 s -- --. 3 9 -- -- 4 4 0 -- 2 -- 10 -- 4 0 -- 1.5 -- 9.5 -- 5 Gitucp NO. 5 5D 5K 5M 5R 0 -- 0.5 -- 10.5 -- 5 0 -- 0 --. 12 -- 4 0 -- 0 -- 11 -- 5 0 -- 0 -- 10 -- 6 Group No. 6 6D 0--0-- 7--9 Group No. 7 The affix "F" designates "Floats" iin all subsec- Lions of Group No. 7 TD 0 -- 0 -- 5 -- 11 ;f 0 -- 0 --. 4 -- 12 :h 0 -- 0 -- 3 -- 13 :k 0 -- 0 -- 2 -- 14 7M 0 -- 0 -- 1 -- 15 7R 0 -- 0 -- 0 -- IS 7T 0 -- 0 -- 0 -- 16 Group No. 8 SS Under 75 pounds per cubic foot loose measure. Gnnrp No. 9 !)T Over 75 pounds per cubic foot loose measure. Quebec siantl-mi Asbestos Testing Machine. Model .Vo. i 01 040 1346 ^ ' 'r u-.-v*- . .- . 't;- 'r ; \ QUEBEC ASBESTOS MINING ASSOCIATION1 * (APPROVED METHOD OF TESTING i ASBESTOS FIBRES) | HI. Oulv the Quebec Standard*Testing Machine Model i No. 2 shall be used for the purpose of testing asbestos fibres. 112. The machine shall be manufactured, installed and operated according to the specifications issued by the National Research Council, and shall be kept in proper adjustment and in good working condition at all times. 1[3: The method of taking samples for testing shall be as follows: When testing Group 3 fibres, a composite sample shall be made up from each and every lot of 100 | bags included in the number to be tested. Each com{ posite sample shall be made up by taking a handful j (about 4 ounces) from every fifth bag of the 100; that ; is to say, 20 handfuls are taken from each lot of 100 bags. _ fl4. In the case of Group 4, 5, or 7 fibres, a composite J sample shall be made up from each and every lot of 200 j bags included in the number to be tested, and each- com; posite sample shall be made up by taking a handful j (about 4 ounces) from every tenth bag of the 200; that is | to say, 20 handfuls are taken from each lot of 200 bags. I f[5. In every case the handful of fibre shall be taken J from well inside the interior of the bag. 116. Each composite sample so made up shall first be al lowed to approximate average work-room temperature . and humidity, and then shall be thoroly mixed on a ! smooth topped table while paasing it thru the hands I with a gentle rubbing action in order to break up and I separate all clots and lumps. It then shall be divided ' into halves, quarters, etc., as necessary, and a representa tive one pound lot shall be weighed accurately and | placed in the testing machine. Formerly Quebec Asbestos Producers' Association j I ! i ' .--- /- ' ! V* S';;.'.. r- . - ,V-t: - ot* oitKtai? * i` - "*,} 'lUj- .. 'Ate-IS*.- Vi'/-*-. -,,~r.~'~\ .. ^ -T-CJ8? QUEBEC STANDARD TESTING MACHINE AND ITS OPERATION The Quebec Standard Asbestos Testing Machine (see illus tration) consists of a nest of 4 boxes, measuring 24%"xl4%", resting on a table -which is driven by ah eccentric with l&jj" throw and l%o" travel. The boxes, which are superimposed one above the other, are numbered from the top down--1. 2, 3 and 4. The bottoms of boxes Nos. 1, 2 and 3 are made of brass screen of the following specifications: Box No. Screen opening Diameter of Wire 1 0.500" 0.105" 2 0.187" 0.063" ( 4 mesh) 3 0.053" 0.047" (10 mesh) 4--Receptacle for the fines which fallthru the other three boxes. To make a teat. 16 ox. of asbestos is placed on the upper most tray (No. 1) which is then covered and tightly clamped. The machine is started and by means of an automatic device is kept going until exaotly 600 revolutions have been made. (The speed of rotation is 300 r.p.m. in the old model No. 1 machine, and 328 r.p.m. in the new model No. 2 machine.) At the end of this time the asbestos which remains on each tray (box) is weighed. This gives the grade of asbestos fibre; the longest fibre naturally stays on the screen with the largest opening, whereas shorter fibre, according to its length, remains on screens (or trays) 2 or 3, or drops into the pan (lowest tray). The more fibre retained on the first screen, and the less fibre falling into the pan, the higher the grade and therefore the greater its value. If, for Instance, a customer buys 3K fibre of the specifica tion 4-7-4-1, it means that in a 3ampie of 16 os., representing the average of the lot shipped, 4 os. will remain on the top screen, 7 on the second and 4 on the third, while 1 os. will go thru all the screens into the pan. It is evident that the figures of the test represent the proportion in ounces of the different lengths of fibre in a pound of asbestos. The product known as "Crude Asbestos" consists of veins of asbestos, of the cross-fibre type, the length of which is ft" and longer; No. 1 Crude being material %" or longer and No. 2 Crude 44" to %*. Crude asbestos is not graded on the Quebec Standard Asbestos Testing Machine. From "asbestos" Philadelphia, Pa. Price--25c .... (Printed In United Bute* of America) 01 THE. ASBESTOS FACT BOOK. 01 040 1349 PART III -AMOSITE AND CHRYSOTILE ASBESTOS SECTION 8 -- THE ASBESTOS FACTBOOK This section's article deals with the theory of the origin of asbestos, its mining locations, its uses in various products, typical analysis of Canadian chrysotile (Blue and Amosite) and various qualities of each. This is a general information section. 01 040 1350 I THE ASBESTOS FACTBOOK i' i r Wherein is given in compact form much information concerning asbestos -- that amazing, versatile non-metaliic mineral .1 4 l I i i * Origin ................................... 2 i Facts ................................... 4 Locations * .... 5 USES ................................... 9 t i Analyses - ................................... 15 Qualities Cover i- i i \ | i "asbestos," Philadelphia, Pa. Second Edition--Feb. 1st, 1944 i OTi ^40-1351 r * S'* ry.-V V V' 1 Ai'iW- Tsy,,-. . . .T-.` *** * - < - /< `"V^ *' . y :r y'a. FOREWORD In the compilation of this small book we have taken information from many sources, and have been helped by various executives in the Asbestos Industry. It is impos sible to list them all, but to all of them our sincere appre ciation is extended. The Asbestos Factbook is for those who need, for one reason or another the main facts on asbestos without hunt ing thru many volumes. Those preparing luncheon talks may find it useful; teachers will welcome it; it can be used to answer the many inquiries received by "asbestos'' and by members of the Asbestos Industry for general informa tion about the wonderful non-metallic mineral--Asbestos. THE ORIGIN OF ASBESTOS (Extracted from "The Origin of Asbestos"1 published in "asbestos," July, 1940) Chemical and mineralogical studies clearly show that asbestos fibre is not of vegetable or animal origin, but en tirely of mineral origin. Taking as an example the chrysotile asbestos mined in Canada, the observed facts lead to the following explanation of its formation. In the greenstone region of Canada, covering hundreds of square miles, the present surface rock was at one time thousands of feet below its present elevation, and under very great pressure due to the weight of the overlying rock and soiL This rock is a variety of olivine called peridotite and is composed of iron, magnesia and silica. In certain extensive areas this rock was acted on by hot ground waters, under high pressure, and carrying dissolved salts and car bon dioxide. The pressure is easily understood when it is realized that the rock was very far below the earth's surface, and the high temperature is explained by the fact that the temperature of the earth increases about 1F. for every fifty feet of depth. From depth alone, this would give a temperature increase of at least 20F. for every 'By M. F. Smith, Research Chemist, The Philip Carey Mfjg. Co. Pape 2 The Asbestos Factbook r f I i 1000 feet, not to mention the hot intrusive rocks also present. These ground waters gradually changed the original rock from the iron-containing peridotite to the magnesia-silica-water (3MgO . 2SiO, . 2H,0) mineral, serpentine. During the alteration the volume of the rock increased, causing innumerable cracks, small and large. These cracks were filled with the hot ground waters, chiefly derived from the slow infiltration of rain or surface waters. This underground water circulated thru the cracks in the rock, descending slowly thru the smaller openings in the rocks and ascending thru the larger openings and cracks. This water at high temperature and containing carbon diox ide under pressure is a very good rock solvent. The water rising in the larger cracks loses pressure and slowly cools, losing some of its solvent power and throwing out a small amount of the dissolved rock. This material deposits on the sides of the crack in the rock thru which the water is flowing, and if suitable mineralizers are present, such as dissolved salts and carbon dioxide, tends to form regular crystal shapes, depositing the molecules in a regular rather than a haphazard manner. Bock salt gives cubes; diamond forms in octahedrons; graphite in six sided plates, gold in octahedrons or cubes. Asbestos forms in easily sepa rable, closely packed filaments, which when teased apart give the workable form in which asbestos is marketed and used. The theory for the formation of asbestos fibre as given in the foregoing is held by many experts, but may be and is contested in some of its minor details by others, based on slightly different conditions present where they made their observations. In most cases the difference of opinion re lates to such details as to how the waters were heated, and what the mineralizers were rather than to the whole of the theory. What has been said above about Canadian asbestos fibre formation holds also for the Vermont chrysotile fibre, Arizona, Russian, Cyprus and South African chrysotile fibre, as well as for some of the other non-chrysotile types. Tht Albertos Factbook Pag* 3 S' cap3a ffumninv 040 TERSE ASBESTOS FACTS If "Asbestos" is not the name of a distinct mineral species, but is a commercial term applied to fibrous varieties of several minerals differing widely in composition, the fibres being diverse in strength, flexibility and consequent usefulness. If The properties of asbestos that give it commercial value are fibrous structure and fire resistance. If Grading of asbestos is on the basis of length rather than quality. Fibres of the same quality range in price according to length. ^ The three varieties of asbestos most used commercially are Chrysotile, Amosite and Crocidolite (blue) the bulb of world production and use, both long and short fibres, is Chrysotile. ^ The earliest use of asbestos known to the world was over 2000 years ago by the Bomans for the wrapping of their dead. Canadian Asbestos (chrysotile variety) was first "discovered" near St. Joseph, Que., in 1860; the deposits at Thetford and Coleraine were found in 1877; but, according to the story of Benjamin Franklin's purse1, asbestos was actually known in Canada, probably by the Indians, as early as 1724. If Blue asbestos was discovered near the Orange River, South Africa, in 1816; the name "crocidolite,"meaning "flakey" or "woolly" stone, was applied to it in 1831; exploitation of the material began in 1893. ^f Amosite (in Central Transvaal) was first known in 1907; the name was given to it in 1918, being taken from the initials of the company most interested in its production-- Asbestos Mines of South Africa. Commercialproduction started in 1916. Rhodesia first reported production of asbestos {chrysotile variety) in 1908--55 tons. >See March, 1939, "asbistos," page 2, for this story. Pagt 4 The Asbestos Factbook . ii ; f i j j j j ' J j i : { f j j j i t | * , { 01 040 1354 U Asbestos in itself does not have low heat conductivity. Its extensive use for heat insulation is because of its fire proof qualities; the porous structure or aircell content of asbestos insulation materials accounts for their insulation value. ^ Italy is called the cradle of the Asbestos Industry because the mining of asbestos and the manufacture of its products began on an industrial scale in that country. f Asbestos was found in the Ural District (Russia) between 1710 and 1720. H Asbestos was discovered in Vermont in 1824, but produc tion was first recorded in 1908. ^ A patent on engine packing using asbestos was granted as early as 1857 to Richard Lloyd, of England. Insulation containing asbestos was first used in 1866; it was made of asbestos fibre and silicate of soda and was in sectional form. Great Britain's asbestos manufacturing industry began in 1871 in a factory founded by the Patent Asbestos Manu facture Limited, of Glasgow, Scotland. % The first known attempt to make asbestos paper was in 1765; it was first made in the United States about 1878. ^ Cape Asbestos Company were the original spinners of crocidolite or blue asbestos--as early as 1895. Ludwig Hatschek, an Austrian, invented asbestos-cement shingles in 1900; they were introduced into the United States in 1905 by the Keasbey & Mattison Company. f Asbestos-cement pipe was first used for carrying corro sive salt water for street cleaning and fire-fighting in an Italian seacoast town. f Patents on asbestos-cement pipe were granted in Italy in 1913; the manufacture of such pipe began by Eternit Pietra Artificiale in Genoa, Italy, in 1915; it was introduced into the United States by Johns-Manville in 1929 and the first shipment made by J-M in 1930. fl Arizona asbestos is important for electrical insulation because of its low iron content. The Asbestos Foctbook Page S t i ! i I i 1l i. t i i 01 040 1355 y- Tf Crocidolite and Amoaite asbestos are highly acid resistant, making them valuable for use in chemical plants. If Amosite asbestos was first spun in England in 1924 by the Cape Asbestos Company. The pioneer in the spinning of Amoaite was S. Weingarten, of South Africa, who spun Amosite yarns as early as 1909. H Asbestos was first used in brake lining in 1906. % A capital investment of $22,000,000 is represented in the asbestos mining and milling industry in Canada. ^ The United States is the largest consumer of asbestos in the world. ASBESTOS IS FOUND: The four largest asbestos producing countries are Can ada, Russia, Southern Rhodesia (Africa) and the Union of South Africa. Next in importance are the United States, Cyprus, Italy and Finland. In spite of the fact that asbestos is found in practically all countries, its occurrence in satisfactory quality and eco nomic quantity is not common. Altho deposits are contin ually being reported, there are very few which upon ex amination are found to warrant the expense necessary for development. The following tabulation forms an index to the varieties of asbestos produced in the various coun tries or localities, ifitci: Southern Rhodesia (chrysotile of excellent quality). Swaziland (chrysotile of excellent quality). Union of South Africa--Transvaal produces amosite, blue and chrysotile. Cape Province produces the wellknown Cape Blue exclusively and extensively. Other occurrences of asbestos (chrysotile) have been reported from Natal. austeia: Short fibered amphibole known as "micro-asbestos" used, in combination with concrete or asphalt, for road surfacing. Australia: Chrysotile of various qualities and lengths is found Pago t Tha Asbestos Factbook i Iit ii i f i \ i i iit } ii i ri t l 1 i 01 040 .. -t. in Western Australia, South Australia, Queensland and New South Wales. Blue asbestos is found in South Australia; the deposits o blue in Western Aus tralia are being developed at the present time. CANADA.: Chrysotile variety, found principally in the provinces of Quebec and Ontario. Asbestos Mines in Quebec are the best known in the world. Canadian quality and grading are considered as standard the world over. china: Deposits of chrysotile worked to some extent in a number of provinces, the most important being in Chihli (Hopeh) Province and Manchuria. ctpbus: Good quality of chrysotile; most of the production is of ``shingle stock" grade or lower. FINLAND: Produces fair quantities of short anthophyllite. INDIA: Produces both amphibole and chrysotile to some ex tent The chrysotile is of excellent quality and low iron content italt: Chrysotile of fair grade and tremolite of excellent quality are produced. Mining and manufacture of asbestos on an industrial scale first began in Italy. RUSSIA: Very extensive deposits of good grade chrysotile are found in the Ural Mountains and have been extensively developed by the U. S. S. R., altho quite large produc tion was recorded previously. SOUTH AMERICA: Deposits of chrysotile in Venezuela are the most im portant from a commercial standpoint Other de posits, some chrysotile and some amphibole, are re ported in Argentina, Brazil, Chile and Bolivia. Very long blue asbestos, not strong enough for spinning, The Alberto* Fnetbook Pag* 7 > i is found in Bolivia. So far no commercial use has j been found for it. i il UNITED STATES: . Arizona Mines produce an excellent long fibre chry- Botile, valuable for electrical work because of its free- j dom from iron. j California has deposits of short chrysotile, not being worked to any extent at present. Tremolite asbestos is also being produced in commercial quantities for Gooch Crucible use. ' I ! ! l Georgia has been the most consistent producer of j amphibole (anthophyllite) asbestos of any of the j states. Large deposits are found in Sail Mountain i (near Gainesville) and at Hollywood. ; i Maryland has a deposit of anthophyllite and tremo- j j lite, from which filter fibres are made. ; I Vermont produces good grades of chrysotile ranging I from shingle stocks to shorts. Wyoming, Montana and New Vork have deposits of good chrysotile asbestos also, but these have not been worked. Deposits of amphibole (principally anthophyllite) t< which are being worked to some small extent are found in North Carolina, Idaho, Wyoming, Montana, Oregon , ` and Alaska. ' Deposits have also been reported in Maine, New York, Pennsylvania, Virginia, Texas, Michigan, Connecticut, South Carolina, South Dakota, Wisconsin. OTHEB COUNTRIES: | < Occurrences of asbestos of various types, principally i chrysotile or anthophyllite, have been reported from ! time to time from Albania, Algeria, Bulgaria, Chosen (Korea), Czechoslovakia, Corsica, Cuba, Prance, Ger- 1 t many, Ireland, Japan, Mexico, Madagascar, New foundland, New Zealand, Philippine Islands, Portugal, Spain, Switzerland, Spitzbergen, Syria, Turkey and ii Turkish Armenia. j Pays 8 The Asbestos Factboolc ''SC.'aBWe.i* i i 4` 01 040 13 ,,> * 'if C1 -V3=i THE USES OF ASBESTOS AND ASBESTOS PRODUCTS In presenting this list of uses of asbestos and asbestos products, we have included only the basic and more important uses--those which consume the largest volume of asbestos (or the product made therefrom) or these which require small quantities of ma terial but perform a very valuable function. We have not tried to include in this list the end use of every item, that is the place where the asbestos or asbestos product is used, or the purpose for which it is used, except where that place or purpose is most important, or unique. For instance, asbestos ;/ blankets are used for fire fighting in hotels, department stores, laundries, dry cleaning establishments, at airplane hangars, by fire departments; the one designation "Asbestos blankets for fire fight ing'' covers a multitude of what might be regarded as the "Uses of Asbestos doth" if the list were carried out to the nth degree. There are also innumerable uses of asbestos and asbestos products which may be extremely interesting but are unimportant from the viewpoints mentioned. Most of these have been pub lished at some time or other in "asbestos" and a complete list, so far as is known, is kept on file. As an illustration, a certain actor's pockets were made of asbestos doth1, but we do not consider "asbestos pockets" suf ficiently important to include in this printed list (Several uses have been added in this 2nd Edition.) USES OF RAW ASBESTOS Yarn Thread Wick packing Rope packing Felt Paper (plain and corrugated) Rollboard Millboard Tnulating win 85% Magnesia pipe covering, blocks and locomotive lgg<"g High temperature Insulation (moulded) (various types) Compressed sheet packing Compound for encasing of motor windings Moulded composition for electrical and other purposes iSee page IS. January. 1930. "ASBESTOS." The Asbestos Factbook Paps 8 1 JJfSbjCeaSait-- isr- r-.wv*; 01 0 40 1:3 59 ^ ^ 'J te (Uses of Raw Asbestos -- Continued) Moulded brake lining and brake blocks Automobile bodies and railway sleepers (moulded composi tion) Filler in Plastics Flooring Pottery and sculpture Asbestos Cement Products, viz: Shingles, siding, tile Wall tile and fiat sheets Corrugated roofing and sheathing Decorative panels Insulated board Floor tile backing Pipes Miscellaneous articles, such as ventilators, flower pots, louvres, etc. Asbestos cement for insulation of boilers Roofing cement FUrnace cement Plaster and stucco Paints, vanishes and fillers Sprayed asbestos (acoustical) Filling for asbestos mattress insulation Insulation of batteries (loose fibre) Insulation of walls and floors (loose fibre) Insulation in underground conduits (loose fibre) In foundations to resist shock Packing for explosives or other materials Wadding in cartridges and timing devices Filter fibres and filter pads Platinized asbestos fibre for filtering Coating for welding rods In cheese making (on which to place spores) Pavement in sewer pipe USES OF ASBESTOS YARN Cloth Tape, electrical and other Brake lining Clutch facings Packing--valve stem, braided and other Gaskets and gasket cloth - Tubing Wick for oil burning apparatus Rope Twine or sewing thread Stocking for lead cable Electric fixture wire covering Page 10 The Asbestos Factbook i f i i \ t i i 1 i ll > > il f 01 040 1360 IJ (Vie* of Aibeitc* Yam -- Continued) Electric cable covering Tying gas mantles For spark plugs t Edges for hair felting USES OF ASBESTOS CLOTH Packing--sheet, high pressure, folded or wound Brake lining, folded and stitched Clutch facings Gaskets Asbestos insulation mattresses Substitute for canvas on insulation where temperatures are high Clothing, viz: Suits Helmets Gloves and mittens Aprons Leggings Berets Tapestry l Hangings for firestops i Blankets for fire fighting Blankets in electrolyzer cells Bags and diaphragms (in oxygen producing) Mailbags i Awnings Rugs 1 i. Theatre curtains Theatre scenery Floor lining in theatres ! Portable motion picture booths i Motion picture screen In acoustical treatment In acetylene welding Gun grips Asbestos faced wipers in commutators Facing for dryer felt Filtering (fruit juices, acids, etc.) Filter in dust collectors Oil filter sack (in automobiles) t Protectors for gas bags in balloons i Oven insulation ) Lining in motors i Lining of laboratories, cooling chambers and other rooms lining of automobile footboards iti The Asbestos Foctbook Page 11 i i i i i 1 i. I t 01 040 -.Jr*-.' n, d*+<'Hsr.: fcijfrfr*jJgS; (TJtea of Aibttto* Cloth -- Continued) Padding for laundry presses and mangles Padding prison cells Wrapping oil tanks and oil lines in engines Umbrellas and shields (protecting firemen) In various medical test apparatus Sand bags (for pressing hats) Conveyor belting In hay curing to preserve aroma and color In cheese making to control temperature Insulation against noise and vibration (especially in airplanes) Fittings for airplanes USES OF ASBESTOS FELT In acoustical work Protection of underground pipes On paper machines Noise insulation Padding in pianos USES OF ASBESTOS TAPE Wick for oil burning apparatus Belts for conveying hot glass or other articles Pull strings for ovens Insulating locomotive steam pipes at bends, etc. Insulating armatures Winding coils Winding buss bars Insulating underground cables Laboratory uses, such as insulation for flasks, test tubes, re torts; tie straps in diffusing materials In glass manufacture for wrapping tines of forks to take bot tles from ovens; reinforcing paddles for. stirring mol ten glass USES OF WICK PACKING As packing For wiping of wire, amor plate or galvanized materials USES OF ASBESTOS PAPER Air cell and other pipe coverings Boiler jackets Asbestos felt roofing Asbestos built-up roofing Asbestos protected metal roofing Gaskets, plain and metallic Wick in oil burning apparatus Tubes in electrical industry Wrapping of electrical wire Wrapping of hot air pipes linings of Stoves Heaters Page U The Asbestos Foetbook *i" i n I ~ ' fii. Hi iWifPMlm . 01 040 -vr (Uses of Asbestos Paper -- Continued) linings of Filing cabinets Cartridges - Soldiers' helmets Carpets Auto mufflers Radiator covers Drum controllers Cookers Electric appliances Armored car roofs Auto floorboards In naTwling ovens to catch drip Insulation of ovens and dry kilns Diaphragm in electrolytic cell Tank covers Reinforcing aluminum foil for insulation I Filtering In window glass machinery to guide hot sheets; to shield hot glass from flying fragments In welding and other processes for protection from heat In annealing (crumbled paper) In chemistry and physics in many various ways Reinforced with cotton thread for automobile tops Covering of rockwool blankets which must be sewed Wrapping of wires and cables Insulating exhausts on automobiles Baking sheets Table pads and mats Construction of air ducts or lining of paper ducts USES OF ASBESTOS MILLBOARD T,inmgt q| Stoves and heaters Safes Garages Motion picture booths Electric switch boxes Dry cleaning machines Garbage incinerators Hoods of automobiles Bottoms of brooder stoves Ovens and dry kilns As fireproof wallboard Ceiling over boilers, smoke stacks, etc, for fire protection Gaskets, plain and metallic The Asbestos Foctboole Page 13 (I I it I r. T*` 1 040 1363: 2?' -. I t i \\ i! i; < -Trfrsrcrna? (Uses of Asbestos MUlboard -- Continued) Paddles in glass mills .; Washers in electrical apparatus T Tent fields and stove pipe rings In metal clad doors (between outside metal and wood core) Table pads and mats Stove mats USES OF ASBESTOS-CEMENT FLAT SHEETS AND WALLBOAHD Interior sheathing (of factories, refrigerator rooms, etc.) Partitions, movable and fixed Exterior sheathing (half-timber effect) Bride-type siding Portable buildings Roofs and sides of small buildings Semi-portable motion picture booths ;; Fireproof layer on insulated board Fire protection around ig<n-- T ining of tireless cookers Backing for dies (in moulding glass) Brake shoes for elevators Hoods over machines or vats (from which vapor rises) Mounting of test instruments and gauges Laboratory table tops Switch boards Cabinets and panel box work Insulators between phases and on arc deflectors Electric motor casings Spark arresters Miscellaneous uses in electrical apparatus Lining for bleaching and other tanks and vats Backgrounds and cut-outs for window displays Blackout or bombproof board USES OF ASBESTOS CEMENT PIPES For carrying of water, sewage, gas and special liquids As gas vent pipes Conduits for electric light wires, etc. Purlins, rafters, trusses, etc, for wartime buildings USES OF ASBESTOS COMPOSITION MATERIAL Insulation compounds Heater cord insulation Electric wire insulation Lamp sockets, rheostat backings, switch parts, arc deflec tors, resistance mountings and other electrical uses *Of many types. Poyt 14 Th Atbcftoc Factbook fc t r Ac ,r jl ** * T''hi.' .. '. *; ' > X L^._ " .,-. :X*-.*i`X.'_/2-w^k;v.a^i..'." V (Uset o1 Asbestos Composition Material -- Continued) Underground Insulation Flooring Phonograph records, buttons and other small objects made of plastic Sealing of percussion caps in large cells 1 USES OF VARIOUS ASBESTOS PRODUCTS IN MOVIES j To localize fires in location ( To protect nearby buildings when fires are set ) For wall sections in sets to prevent reverberations Firebox in fireplaces 1 Insulation of camera booths against sound (Blinders or ears for lights or sun arcs Dressing winter scenes as snow , Dust on cobwebs, old wine kegs, etc. j Noise insulation Insulation for maintaining even temperature "i . TYPICAL ANALYSES Chrysotile1 Blue Amosite 7 Silica (SiO,)..................... 39.05 51.1 50.24 Alumina (A1,0,) ............. 3.67 > '! Ferric oxide (Fe,0,).... ' | 2.41 . 7.80 j? Ferrous oxide (FeO) ... 35.8 32.00 Magnesia (MgO) ............. 40.07 2.3 3.96 Lime (CaO) ...................... Sodium oxide (Na,0) .. set e ee e 6.9 2.12 Combined water (H,0) 14.48 3.9 3.00 i tCanadian (Thetford) 99.68,; 100.0 99.12 The Albertos FactbooJe Page 15 i.ve ! ' \` *><;./' '-iv ->4 - *;.*. , ' ' s V -A , -iV.*f.'V ' w-V-* .. '*/ J'i V>T: , V toiJrn'r*:njSV:* >-v o.i .o;4o^3.6;iMg . '-; -.y.-s:vv .. , -* r^,' < , L,V. * ; VT* \-V AT <.v ^.,y >- v. -V-* :> - ..'T W,.:.T-; A-:-;-.. t..- "IV >.H 'Mr-*...* ; . { :, > - - . > ' ;> ; -u*-f*t.,*rr' tVv/w ...-.7^}/ '-..J. .` .-'.r.:.'! .... * ,;v- . j *4, * }r ``V * . ' =:/' . t' - :;r j- :i ':% ^>V.. * i. ; ,-v. ... _.' r fl J ' A* '*' ' -4 ` -.V j - , .- v'.. ; ; '.. '**'" . ;' A *vi> v.5>. /.* ! f :r * * . v/*%: : rv- *m<7j' -V *. * ! &?>&.' t.i-sV. . ... ... . . ...yr>c;- k<i"`;y' Xti.*.. ** . :V<fc i; ^.v., V->v -J: - r; -' QUALITIES OF ASBESTOS Durability -- Resists...................... Weather Corrosion Fire Heat Acid Vermin Fungi-gTOwth -- Insulates against............. Vibration Electricity Sound Binds................................ Fillers Magnesia Cement Rubber 1;. Filters............................ -{ Acids Alkalies .......................................... ..............{ Attracts. Sludge Dust / }* ( *: r'-' J i. \<- . ** ' * i> ' *' -. -ti. - ;v . .*.if " 'iV'* ;;<' ** r/ /- # . v i . .'V w.* . V^V,-? #'^y:V- : .... >t'A> *v ; . *' 's >f':- 4?. Printed in the United State* Price -- 10c per copy r '' -> .> .* .'.I1." -.' r* . ' ................ ."'.ys'! 't; - ::: "*,:'.. >y...^.vi' A. -.a /< **W' V. v - w"* 'T!.. ? * v . r-> v irfV.H-r- . V.v.ri J.*.. IP*.* .. * .."' .ft., . ^ PART-nr AMQS.LTEL , CHK.YSOTILL AS&EST6S 01 40 1367 AS&E.STOS, A MINERAL OF UNPARALLEO PROPERTIES 01 040 1368 SECTION 9 -- ASBESTOS, A MINERAL OF UNPARALLELED PROPERTIES Section 9 contains concise information on: A. Properties of asbestos fibers. B. Solubility of Asbestos. 1. Chrysotile is readily attacked by acids. 2. Amphibole is fairly acid resistant. C. Effect of heat on asbestos. 1. Chrysotile shows small ignition losses below 700 F and a rapid increase in loss at 1000 F and above. 2. Amphiboles show small ignition losses since they contain only small percentages of water of crystallization. D. Effect of heat on tensile strength. 1. High temperatures and lengths of exposure decrease the strength of chrysotile fibers. At temperatures above 1000 F, the strength decreases rapidly. E. Comparison of surface area of fibers. F-. Comparison of fiber diameters. G. Photomicrographs of chrysotile. 1. Harsh chrysotile fibers. 2. Semi-harsh chrysotile fibers. (a) The harsh fiber has a straight or needle like structure. 3. Soft chrysotile fiber. (a) The soft, silky, chrysotile fiber is wavy. H. Electron micrographs of asbestos. li Chrysotile from Arizona. 2. Amosite from South Africa. 3. Anthophyllite from Georgia. 4. Crocidolite Blue from South Africa. 5. Crocidolite Blue from Bolivia. 6. Tremolite from California. 7. Actinolite from Canada. 01 040 1369 / ,s ~ ' -^s ^ A ,<*"V v i7_:nerrc: ci On^araiieied. > -*-. *->. o ^ A- ,o ^ </ W J*. to* * -Uy M. S. BADOLLET {Annual General Mcciiiaj, Quebec City, Que., April, 11151) (Transactions, Volume LIV, 1951, pp. 151-1G0) Introduction '"P HE DEMAND for general A knowledge on asbestos fibres 1ms increased considerably in recent years. A few publications have printed data showing some of the physical and chemical properties of asbestos, but in many cases this in formation is difficult to find and is seldom available when needed. During the past ten years, JohnsManviile have received many inquir ies on the physical and chemical pro perties of asbestos fibres. Fortun ately, we had some of the informa tion in our files, and we willingly supplied the data. To help relieve this need, we have tried to present briefly in this paper some of the interesting and out standing properties of asbestos. 'Research Center, Johns-Jfanville Corporation, Manville, X.J. (1) For references,-see end of paper. This information was obtained over a period of years by search of the literature and by experimental in vestigations. Properties of Asbestos Fibres Table I (1, 2) presents, in con venient form for easy comparison, data on the principal properties of the several varieties of commercial asbestos' -- actinolite, amositc, anthophyllite, chrysotfle, crocidolitc, and tremolite. Under each variety of fibre is a brief statement describ ing the properties in terms of struc ture, mineral association, origin, etc. Some of the more important data in Table I are expanded and pres ented in Table II (3). Solubility of Asbestos A report ( V, 5) discussing the effects of acids and caustic on as bestos fibres was published in Ger many in 1927. P.c-published several times, it appears :o lie the only in formation available on the suliject. When, several years ago, it be came necessary to obtain technical data, not available in the literature, on the solubility of commercial grades of asbestos, tests were ar ranged following the |>ian 'adopted bv the author of the original article c:o- Samples were obtained i*f nctinolite from Canada, amositc from Af rica, anthophyliitc from Georgia, chrvsotilc from Canada, erecidnlite from Africa, and trehmlitc from California. These samples reprussented fibres obtainable in commer cial quantities. Tney contained some mineral impurities and thus their degree of solubility was not identi cal with that of hand-picked, highgrade crudes from these localities. The acids used in these tests were hydrochloric! acetic, phosphoric, and sulphuric. Ail were diluted to a 25 per cent acid solution, by weight. Table II.-- Physical Properties of Asbestos Chrysotile i Amosite Anthophyllitei Crccidolite ! Tremolite ACTiNOUTE Specific heat B.t.u./lb./'F___ Tensile strength, lb./sq. in.. . Tvni-i. a: max. ignition '..us. eF........ .......................... i-iitrr.tion properties................. k.cct.".c emerge........................... Fusion point. "F........................ npinnebiiitv................................ Aeststar.ee to acids & aikaiies Macr.cttte content.................... Mineral impurities present. .. Resistance to neat................... .or.ianble salts, micro-mr.os. . Relative elec, conductance) Colour........................................... 0.266 80.000 1CO.OOO i 0.193 1 io.CCO : oc.cuo ' 0.210 4.COO & less i 0.201 100.000 3C0.CC0 0 212 ! 1.CC0 I S.C00 1.SG0 1 i.OCO to i.SOO * 1.300 Slow : Fast Medium Pos. ; X^r. Nec. 2.770 2.550 2.675 \ cry good i Fair : Poor Poor 1 Good : Very good 0-5.2 '0 0 iron, chrome, ' Iron iron nickel, lime high Good Poor Coon. Brittle Gooc. Brittle Ve-v good n; hiijh temp. . at high temp. 1.82 1 A* . w*?** : 0.58 i 1.200 i Fast ; Ncg. 2.ISO Fair Good 3.0-5.9 ' Iron Good *1 Poor, fuses 0.84 . l.sro Medium i N'cc. ! 2.400 : Peer : Good ,0 Lime Poor . Fair to ccod 1 ------- Green, crey - Yel'.cwish- co white - crown Yellowish- Blue brown. Some times almost : white White -04--nan- 0 217 1.C00 A less ___ .Medium X*:r. 2.340 Poor Fair Lime, iron Poor -- Greenish T A & L E 1 .~ PROPERTIES OF ASBESTOS FIBRES' Recant studies claim the c ry s ta l stru ctu re is m onoclinic ! I !'...cli fibre sample. ui 10 whs aeeiiraidy wci.uncii .'will }>i;u-cd ill h flask i-onuiinin^ iiOO c.c. nl tin: -3 per ceiil acili nr caiis- tie solution. Two sets of tests were conducted, one at room temperature (2oC.) for indefinite periods, the other at boiling temperature in a reflux con denser for two hours. At the er.d of each test, the fibres were removed from the solutions, washed free from acids or caustic, dried, and weigh ed. Table III shows the solubilities of these particular asbestos fibres in the Tour acids used and in caus tic soda. The action of boiling acids on asbestos fibres is severe, with chry sotiie the most soluble. Acetic acid was not so effective as the mineral acids in dissolving chrysotiie, and caustic' had even less action on this mineral. After chrysotiie fibres had lost 55 per cent of their weight, exam ination showed the fibre structure to be almost all silica, brittle, and very fragile. The high solubility values for ac tinoiite are, it is believed, due to the presence of soJuble minerals as im purities in the commercial product used bv industry. Antfiophyllite seemed to resist acid action better than any other vari ety, with crocidolite second best, tre moiite third, and amosite fourth. All these solubilities would vary depending upon the source of the fibre and whether the samples rep resented pieces of- 'crudes', or milled fibres as purchased on the market. The action of acids and caustic at room temperature is slower than hc: ui.u/jii i.a 0. Il.iO, bOH AciUiOiuc........................... AlUi.j.iu;............................. Anuioiihyllitc................... Chrysotiie...................... Crocidolite........................ Tremoiite........................ 20.:;; 12 hi 2. a; 55.69 4.38 4.77 ; 1 : i2.2:J. 2. (71 0.00 23.42 0.9: 1.99 2\0\ .. i'l r,7 2.1G 55. i8 4.37 4.99 1 i i 20.23 11.35 2.73 525..6795 4.58 . . | i! ! 9.25 6] .9O7O 0.S9 1.25 1.80 Per Cent Loss in Weight. Room Temperature 2o*C. .'or 528 Hours 25% Acid or Caustic I1 HC1 ICFjCOOH ___________________ II________ Actinoiite.......................... | Amosite............................ Ar.thophy Hite...................! Chrysotiie......................... j Crocidolite........................ I Tremoiite.......................... | 22.55 12. CO 2.13 56.00 3.14 4.22 12.14 3.OS 1.04 24.04 1.02 1.41 H,FO 20.10 11.83 3.29 56.45 3.91 4.89 HjSO* 20.60 11.71 2.SO 56.00 3.48 4.74 NaOH 9.43 '6.32 1.77 1.03 1.20 1.65 at boiling temperatures, but if the fibres are kept immersed in the sol vent for a sufficient length of time, the solubilities finally reach the values obtained at boiling tempera tures. The tests at room temperature were conducted for periods of 24 hours, 192 hours, 360 hours, and 828 hours. After each time period, the fibres were removed, washed, and weighed, and the solubility cal culated. The fibres were then re placed in fresh solutions of acid or caustic ta begin ' the next cycle. For convenience, only the solubil ity data for 52S hours are given in Table III since at this point most of the fibres apparently reached their maximum solubility, and this was ap proximately equal to the solubility after a two-hour treatment in boiling acids or caustic. Such information is invaluable to a manufacturer desiring to produce an asbestos product which will be exposed to conditions similar to those in the tests. The most resist ant fibre, if available in commercial quantities, naturally will be selected for the product. Effect of Heat on Asbestos Since asbestos fibres frequently are exposed to elevated tempera tures, it is necessary to determine which fibre most satisfactorily meets the demands. With this in mind, the same fibres as used in the solubility tests were subjected to two hours' exposure-at temperatures varying from 400F. to 1,S00F., and the weight loss measured. The samples, after drying to eliminate surface moisture, were Table IV.-- Effect of Temperature on Loss in Weicht of Asbestos Fibres Temp. *F. . ) 400 eon ; 00 r.oo i/n) : ,u;0 . .Js/J ,-| W<J . .r,vO ci-0 ,Cv0 1 ; ; ; j : 1 Time 2 hr. *' 1 Amosite % \ 0.23 j 0.57 0.80 0.98 ; .07 1.16 i. j>5 '..39 1.43 -- ' 1.52 -- ] 1.53 ron changing in weight due to oxioation. : Anthophyllite 1- % i- 0.05 i 0.24 ! 0.20 : 0.33. o.-:: 0.44 0.52 0.54 0.54 1 0.O4 | 1 10 1.72 i 2.39 1 Loss in Weight Ckrysotile % Crociooute 1 %! Tremolite % 0.30 0.S5 1.73 2.17 2.83 3.S3 1yo0.373^ 13.43 12.62 13.77 0.03 0.25 0.49 0 73 0.83 0.85 1.00 1.04 1.03 -- ' 0.93* --- i 1 1 1 | ! ! ! i. j j 0.04 0.08 0.12 0 22 0.26 0.29 0.27 0.37 0.47 0.56 0.67 1.40 2.18 : i Ifs- < d * < onmr -- rn W ft----- --3-- weighed. p.:u-i\i in ;i inutile where temperature was maintained automatioallv, removed utter a two-hour exposure, eooied to room tempera ture in a desiccator, and rc-weighed. The percentages of loss in weight are presented in Table IV. Generally speaking,' the nmpaiooic fibres such as anthophyliite and tremolite resisted the heat fair ly well at temperatures below 700 JF. The ciirysotile fibre, on the other hand, began to show a sudden ly increased weight loss at 700F.. and a rapid increase above 1,000"T. At higher temperatures, all fibres began to change in physical charac teristics, but the atnphiboles did not disintegrate so' rapidly as the chrysotile fibres. The crocidolite fibre at :.600SF. and higher showed a de finite oxidation of iron and became brittle. Chemical analysis of chrysotile fic-res showed that the ignition loss values varied with the mineral im purity present. Therefore, it was decided to determine the nature of these impurities and their effect on ignition loss values. A series of chrysotile asbestos fi bres from Arizona, Australia, Rho desia, Russia, and Canada were sel ected. These fibres were individual ly tested by placing a sample in an ultimate analysis tTain, with heat ing units electrically controlled. The air taken into the combustion chamber was dried by passing it through sulphuric acid and absorb ing the water and carbon dioxide with magnesium perchlorate, Mg(CIO.)2l and ascarite. The temperature of the combus tion unit was accurately determined by a chromeialumel thermocouple connected oil one end to a potentio meter, ami on the other to the side of tuc asbestos sample in the com bustion tube. Any gases, such as water and car bon dioxide, driven of: tiie asbestos sample wore weighed after being re covered in a second absorbing train containing Mg(C10,): and ascarite in iwo different V tubes. Prior to tiie test, the combustion train was purged for half an hour at `220F. witli dry air. Then the temperature was raised by 1,000F. ami the absorbed gases weighed. La ter, the test was repeated by raising the temperatures to 1,800F. and weighing the absorbed gases. Tiie data shown in Table V give the percentages of water and carbon dioxide driven off each fibre at the two temperatures. The Arizona fibre had a high ig nition loss at 1,800F. This loss con sisted of 12.89 per cent water and 1.91 per cent carbon dioxide. At 1,000F., 0.54 per cent carbon di oxide was expelled from the sample. Calculated as MgCOi, this indicates the presence of 1.03 per cent MgCOj. As the temperature was raised to 1,S00F., additional quantities of carbon dioxide were driven off, which, assumed as having been com bined with CaO, would represent 3.11 per cent CaCO,, indicating that the Arizona fibre tested con tained a high percentage of calcium carbonate. These calculations of CO. as rep resenting MgCOj and CaCO,, res pectively, are based upon the.disso ciation temperatures of these com pounds. Magnesium carbonate dis sociates at temperatures below 1,000F., and calcium carbonate at a temperature of approximately 1,C30F.; a icmpcr.'iture of 1.5Q0VF. for one hour, therefore, should be sufficient to drive off ail the CO;. The Australian fibre contained 12.48 per cent II-O and 0.0G per cent CO;; io in weight on igni tion was 13.3.3 per cent. Recalcula tion of the carbon dioxide as car bonates indicated that this fibre con tained 1.20 per cent MgCO, and 0.G8 per cent CaCO.. as . impurities. The Canadian fibre identified as "A" shows a water content of 14.28 per cent, which is higher than the theoretical amount of water in the asbestos molecule. X-ray diffraction patterns o.i this fibre show the pres ence of brucite, Mg(OH)2, which would break down and produce wa ter during the heating . period, ac counting for the high water content of the fibre. The magnesium car* bonate is calculated at 1.62 per cent and calcium carbonate at 0.27 per cent The Rhodesian fibre contained & much higher percentage of magne sium carbonate than any of the other fibres tested -- 4.85 per cent. The calculated amount of calcium car bonate is 0.79 per cent. The Canadian fibre identified as "B" resembles the "A" sample in having a water content higher than that of pure serpentine, and here again the X-ray diffraction pattern showed the presence of admixed brucite. The magnesium carbonate content was calculated to be 0.S6 per cent, and calcium carbonate, 0.07 per cent. The Russian fibre is a harsh chrysotile having a low water content (11.74 per cent at 1,800F.). The presence of 1.47 per cent mag- Table V.-- Combustion Analysis of Chrysotile Asbestos Source of Fibre Temperature Per Cent F. H,0 Australian.................. Canadian (A)............ Rhodesian.................. " Canadian (3)............ ** Sussisr....................... Canadian (C)............ 1,000 1,800 1.000 1.SG0 1.000 1.SC0 1,000 1,500 1.000 1,300 1.CC0 1,300 1.000 1.SC0 3.37 12.89 1.50 i 12.48 5.47 14.23 1.32 12. CO 3.75 13.31 1.98 ti.ll 2 25 11.53 Per Cent CO, L91 0.66 0.96 0.85 0.97 2.54' 2.39 0.45 0.48 0.77 l.Co - - . w* Total Per Cent H,0-i-CO, 3.91 14.80 2.16 13.44 6.32 15.25 4.36 14.39 4.20 13.79 * -srj 12.30 2.72 12.44 Per Cent Ignition Loss of Fibre ; ! Carbon Dioxide Calculated in Terms of Percentage of Mgco, ; CaCO, 3.87 14.80 2.06 13.33 i 1.03 1.03 1.26 1.26 j 1 i t j 3.11 0.68 6.23 15.17 4.2$ **.C* I 1.62 1.62 4.85 1 . wO i | ! 0.27 0.79 1AW*4? . . TA* %'iJ j '.I.'.'. 0.35 0.86 47 ., .7 i i 0.07 0.66 2.66 12.40 0.90 ! 0. bO i 0.09 01 040 1373 acs'aaa carbonate ;i:ui O.oo per cent calcium carbonate was indicated. Table VI.-- Effect of Heat on Tensile Strength of Canadian Chrysotile Crude Canadian fibre identified as "C" is a semi-harsh fibre with a low wa ter content (11.93 per cent). The total amount of CO; driven off is sm.-.ii and is calculated as represent ing 0.00 per cent MgCOj and 0.09 per cent CaCOj. From these data it can be seen Original cruce--No bent............. Heated 3 min. a: 6005F............... .....................S00F.................. .....................'..COOT............... | ........................ 1.200'F.............. ; Tensile Strength iib./sq. m., 121 I CO 120.CC0 56.GC0 73.000 42,000 Per Cent cf Original Tensile Strength _ 51.6 73.3 59.5 32.0 how readily ordinary ignition-loss figures can be misunderstood if the presence of mineral impurity is not taken into account. For example, most ignition-loss tests on chrysotile asbestos are made to. determine mole cular water content. If the fibre con tains impurities such as brucite, magnesium carbonate, or calcium carbonate, an error is introduced in to the calculations and the fibre is shown to have an ignition loss great er than the theoretical quantity of molecular water. This could be a serious error in determining the as bestos content of an asbestos tex tos fibres are strong. As an inter esting comparison, data have been selected showing the approximate tensile strengths of such materials as iron, steel, cotton, rock wool, glass, and several varieties of asbestos. table VII.--Comparison of Tensile Strengths of Various Materials Type of Material Tensile Strength (Lb./Sq. In.) This would indicate that absestos should have a great surface area when fully opened. Table VIII.--Comparison of the Surface Area of Various Fibres Type of Fibre Surface-Area BY Nj Adsorption (Sq. Cm./Gram) tile, from which the organic fibre is burned purposely and a correction factor is applied for the molecular water content of the asbestos. Effect of Heat on Tensile Strength Ingot iron................... Wrought iron............. Carbon steel.............. Ni-Cr steel................. 45.COO 48,000 155,000 . 243,000 A piece of Canadian crude was set aside - and a number of small fibre . bundles, approximating 20 to 30 microns in cross-section, were sel Piano steel wire........ Cotton fibre............... Rock wool.................. 300,000 73.000 to 89.000 60.000 Nylon.......................... 3.100 Acetate rayon............ 3.800 Cotton........................ 7.200 Silk.............................. 7,600 Wool............................ 9,600 Viscose rayon............ 9.800 Asbestos (Chrysotile) 130,000 to 220.C00 ected and heat-treated at different temperatures in an automatic con trolled muffle. The original fibre bundles had a tensile strength of 131,000 lb./sq. in. Four sets of fibre bundles were heated for 3-minute periods at tem peratures of 600F., 300F., ],000F., and 1,200F. The eiiects on the tensile strengths of the'fibres are shown in Table VI. At temperatures higher than 1,200F., the fibre bundles were too brittle to handle and were con sidered rather weak. The same fibre, when heated for one hour at the temperature stated, had a tensile strength as follows: +00F., 129,000 Ib./so. in.; 600F., 100,000 lb./sq. in.; i,200F., less than 2,000 lb./sq. in. These data show that temperatures and times of exposure affect the tciui'. ` -rjr.gth of chrysotile fibres, cspcc.a../ at !,C00F. and higher, where the strength begins to de crease rapidly. Tensile Strengths of Various .lATiLulA Ls Glass fibre.................. 100.000 to 200,000 Chrysotile asbestos.. 80.000 to 100,000 Crocidolite asbestos.. 100,000 to 300,000 Amosite asbestos.... 16,000 to 90,000 Tremolite asbestos... 1.000 to 8.000 The values given in Table VII are approximate and are cited solely for the purpose of illustrating the comparative strengths of some ma terials used in industry. It will be noted that chrysotile and crocidolite asbestos fibres are exceptionally strong and are comparable in that respect to glass and to some grades of steel. Tbe tensile strength values for the asbestos fibres are based upon breaking loads applied to fibre bun dles measuring approximately 20 microns in cross-section. Comparison of Surface Area of a* iwHSS f. . recognised fact that as bestos fures appear as bundles con The data in Table VIII show the surface areas of nylon, rayon, cotton, silk, wool, and chrysotile asbestos. The values for asbestos are so large in comparison with tbe other fibres tested that it seems hardly possible that they could have such great sur face area. The large surface area value of asbestos is a very important factor. It gives wide coverage and at the same time furnishes strength to as bestos products. Comparison of Finns Diameters The approximate diameter of fi bres of various types has been mea sured and recalculated in terms of the number of fibres or fibrils re quired to equal one linear inch. The results are interesting and they show that a very large number of asbes tos fibrils is required :o make a lin ear inch. Table HI gives apnroxi- rvi*a.o ** i<? ,,1/ivj cz ^ raquic wooi, carton, rayon, nylon, glass, rock wool, and asbestos. The ex tremely small cross-section of asbes licicrence has been made on sev sisting of many thousands of in tos fibres as compared with others wmb"flft 040 1374eral occasions to the fact that asbes dividual fibrils not visible to tbe eye. --B-- Table IX.-- Comparison of Approximate Fibre Diameters Type of Fibre Fibre Diameter in Inches Fibrils in One Linear Inch Human hair................................. 0.00158 630 Ramie............................................... 0.000985 1,015 Wool.............. *............................... 0.0008 to 0.0011 910 to 1.250 Cotton................... .......... 0.0004 2.500 Rayons............................................. 0.0003 3.300 Nylon............................................... 0.0003 3.300 Glass................................................. 0.00026 3.840 Rock wool........................................ 0.000142 to 0.000284 3.520 to 7,040 Asbestos (Chrysotile)..................... 0.000000706 to 850.000 to 0.00000118 1.400.000 method of investigation is of con* siderable interest. On a number of occasions we have had the opportunity of examining asbestos fibre under the electron microscope through the courtesy and co-operation of Dr. James Hillier*. The several varieties of fibres stud ied and discussed in this paper were submitted to the RCA Laboratory to be photographed at two different magnifications to show the structure of the fibrils. Chrytotile The soft Arizona chrysotile at a 4,000 magnification shows fibre bun dles which appear wavy with frayed ends (see Figure 2)t. The same fibre at a magnification of 35,000 shows bundles in which the Harsh type Semi-harsh type Soft type Figure 1.--Photomicrographs of chrysotile asbestos, x 100. Photomicroorafhs of CHRYSOTIX.K Three samples of chrysotile were selected, representing three - differ ent degrees of texture. Each of these three- fibres, mounted on a cover glass, was placed under a microscope and photographed at 100 magnifica tions. They are shown in Figure I. The hank chrysotile fibre at this magnification resembles kite struc ture of splinters and has a needle like structure. The fibres are springy, bulky, fast-filtering, and usually not so high in tensile strength as soft, silky fibres. This type of fibre will break quickly under flexing action. The temi-harth fibre appears part ally as a harsh, and partially as a soft, fibre. The fibres have lost most of the needle-like structure and appear as thick, wavy bundles. It is difficult to show in a picture that they are different from soft fibres. Chemically, they are the same as the latter, but the measurements show quite different physical properties. Such physical tests as filtration, willow-ing, surface area, bulk, and strength will bring out the true pro perties of this fibre and showMiow it differs from the soft, silky chry sotile. ' The soft fibres appear as thin threads which are very soft, not bul ky, slow-filtering, and extremely strong. As noted above, they have the same chemical composition as the semi-harsh fibres, but quite differ ent physical characters. The soft, silky chrysotile fibres make up the bulk of asbestos used in industry. They are available in large quantity and usually are cheaper than the semi-harsh or harsh fibres. . Electron Microoraphs of Asdestos The electron m'croscnpe is a valu able tool for examining materials which are difficult to see by ordin ary microscopic means. Since asbes tos exists in thin cross-seetions, * this --8-- JSCS r Vi fibres appear as hallow tubes (Fig ure 3). This feature was first re ported by Dr. Hillier in April, 1949 (6), using a magnification of 94,000, and it has since been re ported by Bates, Sand, and Mink (7), of Pennsylvania State College. Our measurement of the thin fibrils indicated a cross-section- in the range of 214 to 284 Af units, while Dr. Hillier reported fibril diameters of 180 A units. This would account for the fact that soft chrysotile fi bres have large surface areas and show a preference to open length wise if properly fiberised. Amotiie The amoslte from South Africa, at a magnification of 4,000, shows *RCA Laboratories, Princeton, NJ. tin this and all succeeding Figures showing electron micr'graphs, the magnification has been reduced from that stated in the tex$. The eaption below each Figure gives the mag nification as thus reduced. 'Awirr 040 1375 Figure 2.---Electro micrograph, chryrotilc asbestos, x 1,733. Figure 3.--Electron micrograph, chrysocilc asbestos. x 15,200. straight bundles criss-crossing the field (Figure 4). The same fibre at 3-5.000 magni fication shows rather thick bundles that still remain straight and indi cate a plane of cleavage that is clean-cut and abrupt (Figure 5). Whenever a small fibril is split from a small bundle, its cross-section appears to be approximately 300 A units. However, only a few small bundles appear in this picture, while chrysotile fibre, on the other hand, apparently breaks down lengthwise easily and shows numerous small fib rils within the range of 300 A units and less. The fact that amosite fibre tends to remain as large, thick bundles may well account for its freeness in fil tration, small surface area, and bulky appearance. .Inihophyllitr At a 4,000 magnification, anthophyllite fibres appear as a mixture of thick and thm bundles which show clean, even breaks at the ends (Figure 6). At a 33.000 magnification, some fibrils appear thin and flexible while others are stubby, thick bundles (Figure 7). The cross-section of the thin flexible fibrils is equal to, and possibly smaller than, that of chry sotile fibrils, placing them at ap proximately 200 A units. It is to be noted that no hollow-tube structure appears within these thin fibrils. This particular sample of anthophyllite is soft, not strong, and breaks easily during processing. The mineral impurities in the fibre are visible as plates in the electron micrographs. This fibre is found in Georgia as a mass fibre, and considerable nonfibrous material is associated with the recovered fibre. Crocidolite The crocidolite used .in this in vestigation was the typical blue fi bre from South Africa. Figura 6.--Electron micrograph, anthophyllite asbcatoa. x 1,733. Figura 7 Rlictrnn micrograph, aathophyllita aiheirni a 13,200. At a 4,000 magnification, the fibre of crocidolite fibre which differs appear* as straight, stiff, brittle somewhat from normal African cro bandies, and in most eases the ends cidolite in chemical composition. It show clean breaks (Figure 8). is a soft, silky fibre, not very strong At a 88,000 magnification, the and easily pulverised. bandies appear fairly thick, but At a 4,000 magnification the fibre there is evidence that slender fibrils bundles are dean, tightly bound, and of approximately 800 A units exist show evidence of brittleness (Fig* (Figure 9), though they are few ure 10). and far apart. The brittle nature of ' At a 35,000 magnification, the the fibre probably prevents individ bundles still appear dean and tight* ual fibrils from splitting off length ly held together (Figure 11). An wise, and consequently all that is examination of the few bundles in seen is the large bundles. the field indicates that, if the bun* Bolivian Blue- dies are properly opened, they will show fibrils of approximately 300 A Bolivian blue asbestos is a type - units. Tremolite The tremolite under investigation is from California and Is considered of good quality. At a 4,000 magnification, the cross-section of the bundles varies from thick to thin (Figure 12). The bundles do not appear to be hdd tightly together and they show a tendency to fray. out. Examination of the bundles at 35,000 magnification shows evidence of individual fibrils existing at ap proximately 300 A units (Figure 18). "3K: -I ) I Figure 8. Electron micrograph, crocidolit* aihastoa. x 1,733 Is?#* S' Figura 9.--Electron micrograph, crocidolita aebotoa. x 13,200. -- 8 -- 01 040 1377. Figure 10.--Electron micrograph, Bolivian biu* asbsates, x 1,733. Figure 11.--Elearon micrograph, Bolivian blue asbestos, x 13400. Actinolitt The sample of actinoliie was ob tained from Canada. Previous tests showed high solubility, indicating the presence of impurities. The electron micrograph at 4.000 magnification verifies this fact as it shows only a few fibre bundles, with a high percentage of plate-like min erals present (Figure 14). Sampling this grade of actinolite for electron microscope studies is a considerable problem and many ex aminations would be requiredTit'ovobtain a satisfactory field. ^However, it was recognized that tills, sample was a milled commercial product and the pictures do show the true nature of the material. At a 35.000 magnification, only one large, thick bundle appears in the picture. There is a suggestion of breaks along the end, but there is no indication as to the size of the individual fibril (Figure 16). Conclusion The various properties of the six varieties of asbestos invesligaited are gitcu in convenient table'form to serve as a quick reference^y^-., ,\ Solubility data of the six varieties of asbestos show that chrysotile as bestos is readily attacked by acids and that the amphibole fibres are (airly acid-resistant. The effect of heat on the differ ent varieties of asbestos varies. Chrysotile shows small ignition loss es at temperatures below 700 F. and a rapid increase in loss at 1,000 9 F. and above. The ampinholes show small ignition losses since they con tain only small percentages of wa ter of crystallization. Ignition losses also indicate the presence of water and carbon di oxide. Some chrysotile fibres show the presence of brucite, magnesium Figure 12.--Electron .micrograph, tremolite asbestos. jc 1JH. Figure ,13.---Electron micrograph, ,txsmalite esfreffiy- x 45400. __ ' 01 040 137h V carbonate, and calcium carbonate; approximate cross-sections, and may therefore, great care should be ta help to explain some of the physical ken in interpreting ignition-loss data. properties of asbestos fibres used High temperatures and lengths of in commercial products. exposure decrease the tensile strength of chrysotile fibres. At temperatures Acknowledgments above 1,000F., the strength de creases rapidly. Charts are presented to show, that asbestos fibres have great tensile strength and large surface areas. Photomicrographs at 100 magnifi cation show that the soft, silky, The author wishes to thank Dr. James Hillier and the RCA Labora tory for their help in producing the electron micrographs of the six va rieties of asbestos described in this paper. chrysotile fibre is wavy, whereas the References , harsh fibre has a straight. or .needle'^^^j|ft|y:^B^^bliahed par i.^^^,te??lec^^^niicrb^i^hi^df^thi|J :`'jsix varieties oi-asbestos at 4,000 and'72^ROTE^;;^.'.''-'Pi,,3*nd'vkEWii'_ PV F., 135^000'magnifications show the fibre '' Optieol^Mineralogy, 1942, pp. 277, bundles, individual fibrils, and their 282, 289, and 363. 3. Casey. R. S., Material* of Conetrvction; Indust and Eng. Chent, Vol. 40, Oct, 1948, p. 1793, also pp. 1837-1850. 4. No Author, Acid Reeietane of Aebeetoe; Gnmmi Zeitung, Hay, 1927, p. 1861. 5. No Author, Acid Resistance of Spinnable Type* of Asbestos; As bestos, 1931,- pp. 22-24. 6. Turkevich, J., and Hillier, J., Electron Mieroeeopy of Colloidal Systems; Anal. Chent, Vol. 21, Ap- . ,ril, 1949; pp. 480-481., ;7:"^BA`n,^iT;^FV' Sane^Ia: B., and * Mink, J. F.. Tubular Crystals of CArysettle Asbestos; Science, May 12, 1960, p. 512 I r i ( \ i i {Reprinted from The Canadian Mining and Metallurgical Bulletin, April( 1961) 01 040 1379 a4*" -: -- 10 --