Document K6zXz62yzved9djwM22pvd5E6

FILE NAME: Johnson & Johnson (JAJ) DATE: 1957 Oct 15 DOC#: JAJ029 DOCUMENT DESCRIPTION: Report - Studies of the Physical Properties of Talc, Their Measurement and Comparison, Sent to J &J Protected Documnt-Sub]eet to Proteetlv Ordr JNJAZS5_B00001032 Protected Document-Subject io Protective Order JNJA2B*_0000010JJ PROGRESS REPORT on STUDIES OP THE PHYSICAL PROPERTIES OF TALC, THEIR MEASUREMENT, . AND COMPARISON to JOHNSON AND JOHNSON October IS, 1957 by. W. L . Smith BAT TELLE MEMORIAL INSTITUTE 505 King Avenue Columbu* 1, Ohio Protected Document-Subjectte Protective Order JNJAZSJ00010M K-3262-Z OK'd by O. F . Tangel and A. C, Richardson before typing. ^ oc: 181 F . Tansml ( ) i | A , C, R ichardson R. D. M acdonald W. L ,. Sm ith (3) B att * ! " M e m o r ia l I n s titu te . '\ . . ' SOB KIN AVENUE C O L # MB. US 1. O ' H I - O October 25, 1957 D r. W. H< Lycan D irector of Research Johnson and Johnson New Brunswick, New Je rse y Dear. Dr. Lycan: This letter transm its six copies of our report "Studies of the Physical P roperties of T alc , T h e ir M easurem ent, a id C om p ariso n ". At the p re se n t stage of this investigation it can be seed that the lubricity of the Italian talc .is closely related to its purity, crystalline habit, and p article-size diatribution-and is expressed in bulk density, surface area, porosity, and average diam eter m easurem ents. The acceptable Italian-talc was found.to fall within a sm all range of physical m easurem ents.. Lubricity wgs found to be controlled by the shape of the rela tively sm all content of com paratively larg er particles in the otherwise finer m ixture. It appears feasible that the slip of the Italian talc m ay be improved by the rem oval of the co arser m ineral contaminants. Tour comments on the findings of this investigation will be appreciated. . Very truly yours, W LS:rr E nc. (6) W. L . Sm ith Principal Geologist . M inerals Beheficiation Division ' RESEARC H Protected Document-Subjectto Protective Older FO X INDUSTRY JNJAZM.000001015 TABLE O r CCMTBNTB SUMMARY.............................................................................................................. i*m 1 INTRODUCTION . . . . t 1 discussion o r l u b r ic it y ........................................................................................................... 2 .THE ROLE OF MINERALOOICAL PURITY IN LUBRICITY . ............................... ........................................ 3 THE ROLE OF THE CRYSTALLOGRAPHICHABIT.OF TALC ]N LUBRICITY' ............................... 3 THE MEASUREMENT OF LUBRICITY ............................... ............................................................. ..... 4 M e e u e e l o s ................................... ......................................................................................................... . 4 TU U taM ty B o a r d .................................................................................................................... 4 Tt* U M ellgr of TUc S u ifU i ...................................................................................... .................................................. 1 THE RZLATIONSWPOF LUBRICITY TO PARTICLE-SIZE MSTRIBUTlDH............................... ............................... 9 D is c u s s io n .................................................. 9 S u ltd i^ lH O liM n S n i a M u I l k ............................................................ 9 Correction ef Lubricity Wltk Pcrtiele-Sise Distribution Data ........................................................................................... . MOISTURE CONTENT......................... 15 MEASUREMENT AND CORRELATION OF OTHER PHYSICALPROPERTIES RELATED TO LUBRICITY.....................13 Surface Area DctarmlaaUoa* by Nitrogen Adsorption ....................................................... . 'IS Average (Hamster af P sr tU ia s........................................ ................................... SpeeHte *erfoe# eslsolatad Frees A n r |i ..................................................... , ..............................................IS .........................................IT Peroetcy . . . - .................................................. IS Bulk Oaailty ...................................................................................................................................... 20 CONCLUSIONS.................................................. 21 BIBLIOGRAPHY . . . ............................................................. .........................'. . ............................................................. 23 APPENDIX A description Or lubricity board a nd technique o r o p e r a t io n ............................................................. . a- i APPENDIX B PROCEDURE FOR PARTICLE-SIZE ANALYSIS......................................................................................................................... B -l m rvm w ff Figuta 1. Tbe Lubricity Beard, Stowing Saaaaait f t h l P a c k ....................................................................................... S Figure 2. Underside af Lubricity Beard, Shewing Micreswitcbes and Electric Timer Connected lb Lack-la Relay ................................................................. 6 Figure B -l. Standard riow eheetlpr su in g e f Talc Scrapie . ' ............................................................. ..............................B -l Table 1. Typical Data From Lubricity-Beard Maaturamaat ef Balias Tale Sample (Cranford, 1 1 /2 2 /5 6 )..................... 7 Tabta 1. LubriettyJSeaxd U e u n m n b nod Pa* CantCeetnmiaatiem ef Tale Sampled at Cranford, New Jersey Showing Relation of Lubricity to Purity e f S e m p le ............................................................. I ' \ ' 1 . SA T T I'L iS MEMORIAL I'NST'I T U T E Protected Document-Subject to Protective Order JN JAZS5_00000103* ICaMitniad) Tabla ). Lubrlcity-Beard Data os Flatattoa P redutiol Italien Talc, Shaarina Dalacarloua ETfaet e t Contamination os Lubrleltr................................................................................................ ................................... S Tabla 4. Pravloualy Kaportad ParticU-Slaa S b b tta llm Bata an Itallaa T a is .................... .............................................10 Tabla 5. Partica-S* Diitributioa ot Tbrea Sample* s i Itallaa Talc V .......................................................................10 Tabla 6. Parllcla-Slae Diatribuoa a i Talc IaropUd*at Craaford Pla&t ............................... .... 12 Tabla T. Dviation in Partiol-3la Dietrlbutioo la Waight Par Case o l Talc ampiad at tba Craaford Plant . . . . 1} . Tabla 8. EeUtSeashlp e t Lnbrieitp ts Partida Usa ................................................................................................................13 Tabla 4. Tba Vbbricitjr ai Mixtura* o t Cuarta and riaa Slaat o Talc, Oamaatratts| Ou Control ta ba la tba Cauca Fraattana..................................................................................................... ..............................14 Tabla 10. Lubridty Maaaaramaata e t Itallaa Talc Oaniplaa From Wblch SpisUlo Particls-Siae Fractions Havo Basa E sm o v a d .........................................i , 14 f Tabla i l . furfaca Aria Mauaramants al Bailan Tale, Comparad WIth Lubrfcity-Boerd ktaaaoram aata.................... la Tablar 12. Camparle;of Thaorattsal Avaraga-fllamatar Maaearonwata aad Specific Surface te Lubricity~Board Ktoaiuramoata al Craafsvd Samplat . . . . . . . . . ..................... , . , . \b Tabla 11. Balatteusbip oit Lebricltgr-Board Maaauremanta ta TbaoraUeal Average joiaaaatara u Sisad Fraetiaaa e t Balita Tala ..................................................................................................... 17 Tabla 14. Corrlation ot Spcifi Sortaeo aad Im bridty-Board Maaauratnint* ot Uned Fraettone et Balisa Tal c. . . 10 Tabla 15. Porooltf, Bulle Doaalty, aad U M e ttf at Craatard S i m p l e t ............................................................. 14 Tabla l i . CarralatiOnOf Poroeltjr and Inbrlcity-Board Measuremants at Sisad m e tte n t et Itallaa Taie 20 Tabla IT. Ths RslatdaaMp et Bulle Deority te Intbrlelty^Bsard Maaturameuta e t Stsed Fractloai o( ItaHia Talc . . 20 Tabla 1*. Onmmary of PhpelealProparttea et Sbed Fracttoas of Bailad'T a lc ................................................... 22 .1- M TTtLLI MEMORIAL INSTITUTE Protected Documant-Subjectta Protecve Order JtUAZSSjDOOMf37 STUDIES OF THE PHYSICAL PROPERTIES OF TALC, THEIR MEASUREMENT, AND .COMPARISON by W. L. Sm ith SUMMARY In o rd e r to im prove the physical p ro p e rtie s of talc it is n e c essa ry to be able to m easure the differences in talc and to establish a b asis for the determ ination of im provem ent. To study the lubricous property of talc, an experim ental -lubricity m eas uring device was built, -and the behavior of different talc sam ples was com pared with their other physical properties. The com parative physical m easurem ents were made - upon siged fractions and whole sam ples of Italian talc with conventional laboratory devices. It was found that the .acceptable Italian talc fell within a sm all range of the physical m easurem ents and that the sam ples with the m ore desirable slip have the g reater surface area, the sm aller average p article diam eter, th e'g reater ratio of-voids to to tal volume, and the le s s e r bulk'density. L ubricity was fouhd to be controlled by the shape of the relatively sm all content of com paratively larger particles in an other w ise-finer m ix tu re. At the! p re se n t stage of the investigation, the im provem ent of the slip of the Italian talc appears feasible by the rem oval of the coarser m ineral contam inants. INTRODUCTION is ------------------------ The talc currently used by Johnson and Johnson, obtained from Pinerolo, Italy, is believed to be a blend of five o r m ore different grades of ore which gives a high quality, .lubricous powder. In a proposal for rese a rc h on the im provem ent of the pro p erties of talc, dated June 4 ,' 1956, it was proposed to study the basic p roperties of the acceptable Italian talc and to determ ine if and how the quality m ight be improved. The development of objective tests which m ight serve in the evaluation of talc was recommended, with the in itia l work-to be done upon' the product now u sed by Johnson and Johnson. In o rd er to determ ine improvement in die quality of talc, however, it is necessary to m easure the apparently sm all differences between, acceptable talc and talc of lower quality. P reviously, m easurem ents have been m.ade by subjective m ethods only, which w ere thought to be of insufficient precieion to m easu re sm all differences. The develop m ent and co rrelation of physical m easurem ents has been undertaken to p erm it the m easurem ent of improvement. The m easurem ents of the physical properties of accept able talc, and their range, have been made upon a se rie s of one kilogram sam ples of grade "EGT E xtra 00000" taken a t weekly intervals from the conveyor at the C ranford, New Jersey , plant ju st before the talc enters the ribbon blendove. An additional large sample of talc was obtained.for tests requiring larg er volumes of m aterial. ' " As a test for the comparative lubricity of talc samples, a lubricity board was con structed. This device, though not providing absolute values, gives reproducible- battelle m e m o r i a -l institute Protected Document-Subject to Protective Order JNJAZ65_000001038 I 2 relative figures, with which the other physical p roprties, which can be m ore easily m easu red , m ay be c o rre la te d . This study, 'When coupled with proposed work on a b ra siveness and other p ro p e rtie s, should indicate th course to follow in beneficiation, the p rim ary work on which Battelle reported in a letter dated June 12, 1957. The flotation work to date has been a laboratory expedient of producing talc of superior quality for physical tests. DISCUSSION OF LUBRICITY This report deals with lubricity and other physical proprties including p articlesize distribution and surface area, which are pertinent to lubricity. The desirable quality in talc, however, is only p artly a m atter of lubricity. That is, talc with the desired "feel" (as sensed subjectively) is not determ ined either by very high or very low lubricity (diminution of friction) but by a balance of physical p ro p ertie s which produces a p articu lar sensory effect. This quality is refe rre d to in this rep o rt as slip. The p rim ary determ ining factor is the platiness of fine grained p a rticle s sliding over one another under slight p ressu re --not being lubricous in die sense of bearings which cut down frictio n by transm itting- the moving force s'-to the rolling of an interm ediate body, producing point friction; not being lubricous in the sense of -a viscous fluid which buffers contact; but being lubricous in the sense of a series of leaves which im part the re la tiv e m ovem ent of two bodies along se v era l planes p a ra lle l to the contact, producing the sensation of softness of surface contact. The nature of the sliding of the platelets is a m atter of kinetics, the changes in types of m otion produced by applied fo rc e s. A c e rta in intensity of fo rce is req u ired to m aintain sliding between any two su rfa c es, and tiiiB v a rie s with die nature of the s u r- fa c e s. When $he applied fo rce is d istrib u ted along num erous p lan e s ra th e r than between two su rfaces, the resista n c e to relative motion between the two bodies is distributed among a se rie s of translation m ovem ents rath e r than in a Rotational m ovem ent or in the overcom ing of in e rtia in one plane. Inasm uch as the coefficient of sliding fric tio n is apparently much less between talc platelets than between talc and flesh, the total friction resulting from the sum of tran slatio n movements is.n ecessarily le s s than that of flesh in contact with flesh, and thus die lubricous.property is sensed.' The force producing the relative motion of two bodies is applied to''the several planes of free moving talc plate lets, which orient their g rea test surfaces norm al to the force applied; the contact of this series of p arallel talc planes with rflesh produces the silky o r smooth sensation desirable in high quality talcum powder. G rit (granular and acicular particles), where present,-introduces point friction as in bearings, or plowing and thus is the prim ary-objectionable-contam inant in talcum powder. -" The lubricousness or slip of talcum powder is determined by its m ineralgical purity, the crystallographic habit of the talc, the size distribution of the powder, its m oisture content, and-the nature.of the-contam inants. M ost of these facto rs m ust be determ ined petrographically, often on separated fractions of the powder. Other physical properties, such as surface-area, average diam eter, porosity, and bulk density, may be m easured m echanically. Such physical m easurem ents have been made, and the data have been co rrelated to determ ine' which p ro p erties are significant in ground talc which h as the d e s ire d slip. M easurem ents have been m ade to e sta b lish the BATTEL-LE M E - M O R I A- L I N S T I T U T E Protected Document-Subject to Protective Order JNJAZ_00000103B 3 optimum lim its of many of the properties relevant to lubricity. 'D ata relevant to color, reflectance, m oisture content, alkalinity, and abrasiveness will appear in a subsequent report. O' THE ROLE OF MINERALOGICA!. PURITY IN LUBRICITY The Italian talc contains from about 9? to m ore than 99 p e r cent pure m in eral talc. The predom inant contaminant is carbonate, which is presen t in all size fractions, being slightly m ore abundant in the fines, jfanog other contaminants, present in trace amounts, are amphiboles, rutil, zircon, apatite, and titanite. The Italian talc is essentially free of opaques. The contaminants are generally prism atic or angular p articles which act as g rit and introduce point friction. A few such equidimensional or acicular particles present in an otherwise platy talcum, particularly if the grit is p res ent in the c o arser sizes, may be easily noticed subjectively. They dim inish the lubricous feeling by the introduction of plowing, bearing-like p articles, and the disrup tion of the lam ellar movement of the talc p articles. Inasmuch as the contaminants generally have diam eters considerably g reater than the thickness of talc platelets, their rem oval would improve the slip of any platy talc, in which they occur in an effective amount. The sm all percentage of contamination in the Italian talc is an effective amount, as dem onstrated by lubricity tests on a sample upgraded by froth Dotation. F u rth er discussion of the nature, of the im purities ofJa le was reported in e a rlie r B attelle re p o rts to Johnson and Johnson dated May 11, 19591)* F eb ru ary 29, 1956'^', May 28, 1957(3), and July 25, 1957<4). ,, /T H E ROLE OF THE CRYSTALLOGRAPHIC HABIT OF TALC IN LUBRICITY Platy talc is the m ost desirable for the purposes of the Sponsor. W hereas acicular and granular talc p articles plow or ro ll, producing point friction, platy p a rti cles slide over one another producing the soft lubricous sensation desirable in talcum pow der. The Italian talc averages about 10 p e r cent fibrous o r ac ic u la r p a rtic le s and about 90 pa? cent p la te le ts. The amount of g ran u lar talc p a rtic le s is.negligible. Fibrous and granular particles of talc, though physically softer than the foreign m ineral contaminants of talc ore, are none the less undesirable - if to a lesse r degree. Such p articles are m ost undesirable when p resen t in the larg er grain sizes where these crystals or aggregates may act as bearings or irritants. W hereas different m inerals m ay be separated from one another by physical processes, such as the rem oval of carbonates from talc by flotation, m ore difficulty is involved in separating particles of m onom ineralic, impalpable powder on the basis of their crystallographic habit, except where the crystal types concentrate in specific size fractions. Until beneficiation procedures for concentrating talc with the desired crystallographic habit are developed, talc which has the crystallographic habit p re ferred m ust be obtained by selective mining. A detailed discussion of the various crystallographic habits of talc appears in a B attelle .rep o rt to Johnson and Johnson dated F e b ru a ry 29, 195<>(^ . * Reference, are given on page S3, B A T T E L L. E MEMORIAL INSTITUTE Protected Document-Subject to Protective Order JNJAZ55_000001040 4 j / . THE MEASURSMENT'OF LUBRICITY D iscu ssio n Although the d ssirsd property of tele, the slip or optimum balance of sire d is tr i bution and friction is only partly a n u tte r of lubricity, it is correlative within-certain lim its of lubricity. A standard method of objectively m easuring the lubricousness of talc has not been devised previously. .The lubricity has been determ ined comparatively by feeling a pinch of powder between the fingers. People experienced in so testing talc subjectively re able to -distinguish fine differences in quality. Since the desirable id undesirable qualities of talc are a subjective m atter, it is likely that subjective testing is. preferable. However, since the subjective tests are a m atter of sensation, involving hum,*11 rea c tio n to se v e ra l physical p ro p e rtie s, such te s ts a re of little help in devising m ethods of im proving the physical p ro p e rtie s of tale .or of m easuring sm a ll differences in p articu lar p ro p ertie s. B eciuse of this it was n ecessary to build a device to ohjec' tively te s t and m e a su re lu b ricity , a p a rt fro m the other p ro p e rtie s which contribute to the desirability of talc. It is not to be in ferred that an objective te e t can replace the subjective te st or that pleasantness of sensation is m echanically m easurable; however, the physical properties which contribute to the unctuousness of tale can b a m easured and their optimum lim ite can be determ ined; Thus the m eans of improvement of tales can be visualized. The figures obtained on tha lubricity-boar 'experim ents are com pared with die m ore easily made m easurem ents of other physical properties in order to determ ine if there ie a correlation and to establish the desirable lim its of p articular properties in acceptable Italian talc.' The Lubrieity Board In o rd er'to obtain quantitative m easurem ents of talc Samples, against which the m easurem ents of other physical properties could be compared, a simple machine was constructed with a minimum of interacting physical factors. This, device consists of a wooden plane inclined a t 25 d e g re e s, which ie covered with talc (F ig u re 1). The lu b ricity ie d eterm in ed by m easu rin g tha tim e it takes a 226-g ra m s te e l puck to slide over two m icroshdtches spaced 5 feet a p art (Figure 2). The mic.roswitches actuate an electric tim er. The lubricity board wae designed as a prelim inary device in m aking lubricity experim ents; however, a routine method-of m easurem ent has been established and the device has dem onstrated a reproducibility with an accuracy of m ore or less 1 per cent. . Although m ore p recise m achines might be built, the lubricity.board has proven to be an adequate means, of m easuring the com parative lubricity of talc sam ples and to'be adequately p recise for the com parison of data from other physical m easurem ents. The m easu rem en ts m ade on the lu b ric ity b oard a re1p rese n ted in te rm s of . xxx second, the fig u re s rep re sen tin g the average of fifty read in g s. `A typical set- of fig u re s is shown in Table 1. A d escrip tio n of the lu b ric ity b o ard and.the technique of its operation.com p rise s Appendix A. BATTKLLK M EM O RIAL INSTITUT Protected Document-Subject to ProtecSve Order fl JNJAZ85_000001041 5 N40207 FIGURE I . THE LUBRICITY BOARD, SHOWING DESCENT OF STEEL PUCK SATTELLE M EM O RIAL INSTITUTE Protected Document-Subject to Protective Order JNJAZ5SJM0001042 i FIGURE 2. UNDERSIDE OF LUBRICITY BOARD, SHOWING MICROSWITCHES AND ELECTRIC TIMER CONNECTED TO LOCK-IN RELAY BATTELLE MEMORIAL INSTITUTE Protected Document-Subject to Protective Order I JNJAZUL000001043 7 TABLE 1. TYPICAL DATA FROM LUBRICITY-BOARD MEASUREMENT OF ITALIAN TALC SAMPLE (CRANFORD, 12/22/56) Serie e 1 M easurement in Seconds Series 2 Series 5 . Series 4 Series 5 0 .9 6 ^ 0.98 0.95 0.95 0.97 0.97 0.96 0.95 0.97 0.94 0.97 0.96 0.96 0.95 0.96 0.95 0.96 0.97 0,96 0.97 Average 0.98 0.97 0.97 0.97 0.96 0.960.97 0.98 0.97 0.97 0.965 second 0.97 0.96 0.96 0.98 0.98 0.97 0.96 0.98 0.97 0.99 0.97 0,97 0.96 0.95 0.96 0.94 0..-97 0.98 0.95 0.97 () lubricity board newly covered for each mriaa of ten d id . C o n trary to preconceived ideas about tire behavior of solid lubricants, the puck was found to slide fa ste r on poorer grades of talc than on cleaner sam ples with b etter slip. The controlling factor is the presence of contaminants or equidimanaional p a rti cles which act as bearings while p u rer talc, within the lim its of the p articular size distribution, p resen ts a surface composed of fla t platelets, producing m ore friction and slowing the descent of the puck. It is not suggested at this time that Johnson and Johnson conduct sim ilar experi m ents on a lubricity board. Until the lubricity studies are completed, it is intended that the lubricity board serve only as a basis for comparison with other m easurem ents by whieh the physical prop erties which control lubricity can be evaluated. The Lubricity of Talc Samples L u b ricity -b o ard m easu rem en ts w ere m ade on 15 sam ples of talc obtained from the C ranford p la n t of Johnson and Johnson^ collected a t reg u la r in te rv als from August 10 to D ecem ber 22,1 1956. Table 2 lis ts the fig u res obtained fo r each sam ple. The readings ranged from 0.936 second for the sample which perm itted the faste st descent of the puck to 1.083 seconds for that sample which m ost slowed the descent. To te s t the hypothesis that the faste r descents were due to bearing-like con tam inants, the lubricity figures w ere compared to those of the percentage of contamina tion. Table 2 lis ts the amount of contamination as com pared to the lubricity of the sam ples. The contamination figures represent m icroscopically identifiable particles ** and do not include the im palpable fin es. Although c o rre la tio n w as not p e rfe c t, the relationship of contam ination to lubricity is clear in the extrem e instances. The talc containing the g reater amount of contaminants perm itted the faste r descents on the lubricity board. The alight differences in contamination were not discernible subjectively. BATTELLC MEMORIAL INSTITUTE Prelected Document-Subjectto Protective order JNJAZSCJW0001044 8 TABLE 2. LUBRICITY-BOARD MEASUREMENTS AND P E R CENT CONTAMINATION OF TALC SAMPLED AT CRANFORD, NEW JERSEY, SHOWING RELATION OF LUBRICITY TO PURITY OF SAMPLE Date Sampled 9-6-56 11-6-56 9-12-56 9-19-56 10-18-56 8-10-56 9-27-56 8-28-56 10-29-56 10-4-56. 8-20-56 10-12-56 12-22-56 11-30-56 11-15-56 C o n ta m in a tio n ^ *), per cent <1 1 <1 <1 ` 1 1 1 2 1-2 1-2 2 . 2-3 2 2-3 2 Lubricity-Board M easurements, seconds 1.083 (slowest) 1.053 1.030 1.028 1.025 1.021 1.017 1.007 1.006 . 0.982 0.971 0.968 . 0.965 0.952 0.936 (fastest) (a) Dtterpiined pctrogrtphlcally. Inasmuch aa the contamination figures w ere sm all, were d o se together, sad could be preju d iced , the contam inants w ere rem oved fro m a sam ple Of talc by fro th flotation and the products w ere tested on the lubricity board. The te st resu lts, which a re also noticeable subjectively, a re given in Table 3. TABLE 3. LUBRICITY-BOARD DATA ON'FLOTATION PRODUCTS OF ITAUAN TALC, SHOWING DELETERIOUS EFFE C T OF CONTAMINATION ON LUBRICITY Product Starting sample Float product'*) Nonfloat product^) Lubricity-Board M easurement, seconds 0.990 1.046 (superior) 0.873 (inferior) Ce) EiientUUy puis ta lc, rqxuendng 90 par cent o f itardng lam ple. (b) 8 per cent talc, 18 pet cent contaminent, npttaenting 10 p a cent of Halting (am ple. The essentially pure talc product produced a slow er descent of the steel puck than did the unseparated sample, and the flotation tailings perm itted a descent considerably faster than did the unseparated sam ple. It m ay be concluded, on the b asis of several experim ents on die lubricity board, that the p u rer talc with the better slip req u ires a longer tim e fo r die puck to slide, while die sam ples m ore contam inated with granular I "bearings" p erm it fa ste r descents. Although Ihe details of p ractical bensficiation of * this tale by froth flotation have yet to be worked out, the amenability of the talc to _ battelle memorial institute Protected Document-Subject to Protective Order H JNJAZ55_000001046 9 flotation and the obvious improvement in the purity and slip of the product indicate that beneficiation is a feasible consideration for the improvement of the Italian talc. C THE RELATIONSHIP OF LUBRICITY TO PARTICLE-SIZE DISTRIBUTION Discussion The d e sira b le slip in talcum powder does n<^t depend alone on the physical lu b ric ity of the m ineral but on num erous interdependent physical p ro p erties, one of the m ore im portant being particle-size distribution. The relative amount of grains in different sise fractions, the extrem e sixes, and the crystalline habit of grains of different sises play a m ajor role in lubricity. Comparatively larg er grains in an otherwise fine powder m ay ro ll like bearings, plow, or act as b a rrie rs to the free movement of sm a lle r platelets.* Too la rg e an am ount of v e ry fine g rain s m ay behave as "flour11 dsspite their p article shape and m ay disrupt or m ay clog the movements of larger platelets. Size distribution is reflected in bulk density, porosity, surface area, and average diam eter m easurem ents. The sam ples of Italian talc w ere found to have physical p ro p erties which fall within a sm all range of many of these m easurem ents and which can be related to lubricity-in some instances. Too many variable properties exist in talc to a ssess specific requirem ents for many physical m easurem ents; however, in testing for acceptable talcs, those ores with properties sim ilar to the Italian talc should also be expected to have m easurem ents within or close to th range of those obtained oh the Italian talc. The m easurem ents should be a useful guide in the blending of talcs and for the rejection of inferior grades. Battello wishes to emphasize that imm ediate conclusions should not be drawn from the following physical m easurem ents alone, inasm uch as they represent but half of the story. A forthcoming rep o rt which will deal further with lubricity and other ph y sical p ro p e rtie s such aar w hiteness, ab ra siv en e ss, and m o istu re content, w ill expand the lis t of the p ro p erties required for an acceptable talc. Although many talcs m ay be rejected because they fail to m eet certain physical requirem ents presented here, acceptability involves additional factors. P artic le -S iz e D istribution in Xtalisn Talc I ... ....... In a previous re p o rt to Johnson and- J o h n s o n ^ , B attelle re p o rte d a d ry s c re e n analysis and a p article-size distribution of Italian talc based on both dry screening and sedim entation in w ater. These findings are repeated in Table 4. F urther, extensive p article-size distribution studies w ere made showing that three replicate analyses of a large sample of Italian talc were closely reproducible and in close agreem ent with the e a rlie r analyses, although obtained.from a separate sample (Table 5). Appendix B contains a description of the procedure for p article-size analysis* BATTELLE MEMORIAL INSTITUTE Protect! Document-Subjectto Protective Order JNJAZ5SJM0M1046 10 TABLE 4. PREVIOUSLY REPORTED PARTICLE-SIZE DISTRIBUTION DATAU) ON ITALIAN TALC a. Dry Screen Analysis Tyler Mesh Size +150 -150+200 -200+270 -270+325 -325 * Weight P e r Cent 0.1 1.8 2.1 13.5 82.5 T O b. Approximate Particle-S ize Distribution Based on Dry Screening and Sedimentation in Water Approximate Weight Size P er Cent -1004-200 M esh 2 -2004-325 M esh 16 -325 M esh + 15 M icrons 62 -15 M icrons 4- 10 M icrons 9 -10 M icrons 11 100 TABLE 5. PARTICLE-SIZE DISTRIBUTION OF THREE SAMPLES OF ITALIAN TALC Size +200 m e s h ^ -200 m esh + 325 m esh -325 m esh + 400 m esh <38 m icrons} -38 m ic ro n s + 30 m icro n s -30 m ic ro n s + 15 m icrons -15 m icrons Average Weight P er Cent .1 10 7 57 12 . 13 1 P er Cent Deviation From Mean 0.12 0.97 1.3 5.18 0.8 3.1 (*) Tyler. ATTELLE M EM O RIAL INSTITUTE Protected Document-Subject to Protective order JNJAZ55JW0001047 11 To cheek the variation in p article-size distribution of the talc sampleB from C ranford, a a e rie s of m easurem ents by- d ry screening .and sedim entation w ere m ade on 12 sam ples. Table 6 lis ts the weight p e r cent of each siee fraction. One of the sam ples, Cranford 10/4/56, might be eliminated statistically from the sample popula tion; however, the variation is real and its data are included in the weight per cent deviation from the m ean (Table 7). The effect of the variant sample shows clearly in the m easurem ents of average particle sise, specific surface, bulk density, and porosity (T ables 12, 15)v The cause of the v ariation is not obvious p etrographically, the sam ple being sim ila r.to the o th e rs except in size distribution. ThiB v arian t sam ple dem onstrates that the Pinerolo product is not uniform. Also, since the larg er coarse fra c tio n does not cause the expected effect on the lub ricity m easu rem en t a s do v a ria tions, within the norm al sise distribution population, it shows that the m atter of lubricity is m ore complex than is indicated by variations within a sm all range in particle-sine distribution. The Cranford samples have m inor variations in p article-size distribution. In all of the sam ples, how ever, die -400 m esh (38 m icron) 4 30 m icron fractio n constitutes about one-half of the sam ple, with m inor amounts in the sm aller and larg er fractions. This distribution should be kept in m ind should platy talcs of other distributions be con sidered. Inasmuch as the sine distribution m ay be as much a m atter of the grinding and blending of o res ae of the physical nature of the ore, fabrication of acceptable talcum powder from lower grade ore might be accomplished by a proper blend of sized fractions of platy talc. C o rrelatio n of L ubricity With P artic le -S iz e D istribution Data In order to correlate the particle-size distribution and lubricity data, a large sample of Italian talc was sized and the size fractions w ere tested on the lubricity board. Experim ents clearly showed that the co arser fractions perm itted a faster descent of the puck while the finer fractions produced a slower descent. This is ap parently due to the m ore equidimensional hearing-like particles in the co arser fra c tions. Table 8 dem onstrates the relationship of p article size to lubricity, showing the larg e r, m ore desirable, lubricity figures for the fines, the lower fo r the coareer, gritty fraction. Inasmuch as the lubricity of talc involves the physical pro p erties of m aterial of various grain sizes, lubricity m easurem ents w ere made on various proportional m ix tu re s of specific p a rticle -size fractions and on powders from which specific p a rticlesize fractions were, rem oved. In order to determ ine if the o v er-all lubricity was con trolled by the coarse or by the fine sizes, a saries of lubricity m easurem ents was made on pro p o rtio n al m ix tu re s of the fine (-400 m esh) and c o a rse (+250 m esh) sizes. Table 9 clearly shows that the control is in the relative.am ount of co a rse r to finer grains. That is, a sm all amount of coarsa p articles added to an otherw ise fine powder has a pronounced adverse effect on lubricity, w hereas a sim ilar percentage addition of fine p a rtic le s to an otherw ise co arse-g rain ed pow der h a s com paratively little effect on lubricity. It m ay be concluded .from this study that the rem oval of the co arser p a rti cles, which tend to be m ore equidimensional, w ill im prove the slip. On the other hand, the addition of fines to gritty o r granular powders m akes com paratively little im provem ent. BATTELUa Protected Docum ent-subjeetto Protective order M EM O RIAL / INSTITUTE JNJAZ66JD0000104S TABIX 6. PA RTICLE-SIZE DISTRIBUTION O F TALC SAM PLED AT CRANFORD PLA NT (a) See 12 peo- * Ntn hN* H S f*M4 pN-< mO cn I-* cn CM in i to M pH M cn n 3 3 o 5 h U u o N 9M*s cCMn 9 Nm mp* HCD fM-* M* iH so O M M 9O0 I S O-S *-49 sO cn to vfl h h i--i h <n s HH CM n0 m--* 1 4- a A a S p s 2 CM ' 0 sO t 'O r- r* CM O' N <0 o uv . cn e in >0 N co c- in 'D in vO sO n ni 1^ 1 s s i so m IA in in in in m $y a<9 9 * 44 cono itn- in 00 nmO r<M- tt-- O00' NnO 0O0' con ccnn OM' 22 in o vD' t- t- t- sO sO O'- t- fM o O' --I r*< * ?? II $ 2 iO u> s ? s s o cp * cOn' IQ IA tA f5 m in N 4 4 O cn m> ' 55 in (M O' O' in S IM cm \mD 00 60 MN s * O H M0 M9 sP MP tn 'P >D % MS siin? in \i0n >ion* mi T in CM A 1 r in . in in l I 1 cm o m cm n h 4I t HI HI 7 5 hi d, 3 | N1 Hl HI O' ^ O' O' 2 oo DH H H sattelle M EM O RIAL N S T IT U t E Protected Document-Subject to Protective Order JNJAZS6JN 0001048 13 TABLE 7. DEVIATION IN PARTICLE-SIZE DISTRIBUTION IN WEIGHT P E R CENT OF TALC SAMPLED AT THE CRANFORD PLANT Deviation, weight per cent (Excluding Sample 10/4/56) Deviation, weight p e r cent (Including Sample 10/4/56) +200 m esh(a) -200 m esh + 325 m esh -325 n t t h + 400 m esh (38 m icrons) -38 m ic ro n s + 30 m ic ro n s -30 m ic ro n s + 15.m ic ro n s -15 m icrons (a) Tyler, 0. 26 2.44 1.78 8.50 5.42 3.72 0.39 2.44 1.78 12.85 10.75 3.72 TABLE 8. RELATIONSHIP OF LUBRICITY TO PARTICLE SIZE Tyler Mesh Size Lubricity-Board M easurement, seconds U nseparated +200 -200+250 -250+270 -270+325 -323+400 -400 0.990 0. 889 0.951 0.980 1.030 1.043 1.099 M TTELLI MEMORIAL INSTITUTE Protected Docum ent-Sutyeetto Protective Order JNJAZSSJMOO01MO 14 TABLE 9. THE LUBRICITY OF MIXTURES 0 7 COARSE AND FINE SIZES OF TALC, DEMONSTRATING THE CONTROL TO BE IN THE COARSE FRACTIONS P er Cent Fines (-400 Mesh) P er Cent Coarse (4250 Mesh) L u b ricity -B o ard M easurement, seconds Difference in L u b ric ity 0 100 0.951 .000 10 90 0.951 .009 25 75 0.960 .010 50 50 0.970 .016 73 25 0.986 .052 90 10 1.028 .061 100 0 1.099 F urther m easurem ent of the effect of p article-eize distribution on lubricity were made by testing whole powder from which different size fractions had been rem oved. The m ea su rem e n ts, Table 10, dem onstrate that rem oval of the fines d e c re a se s the quality of the pow der, w hereas rem oval of the coarse fractions im proves it. It would have to be determ ined by further tests of beneficiation products whether it is m ost advisable to rem ove entire sire fractions or m erely the sm all percentage of coarse contam inants. T A B U 1 0 . LOBKCITY MEASUREMENTS OF ITA LIA N TALC SAMPLES FROM W HICH SPECIFIC PARTICLE-SIZE FRACTIONS HAVE BEEN REMOVED X Repretentt Ptacdoot Removed Ptom Whole Powder 17 Repm onti Frictions Toned Lubricity-Bottd Tyler Measurement oK*7 X eit M tA tit* Size Friction 1 +800 0 .8 8 0 U -800+830 0 .9 5 1 0 -8SO+8TO 0 .9 8 0 U -210+825 1 .0 8 0 X -386+400 1 .0 4 8 X -400 1.09S X Lubricity-Board Meaiurement 0 .8 4 5 Approximate Weight Per Cent o f 07. Friction Removed (a) Reposted (torn Table 8 for comparative purpoiej. Ten 3 0 0 U U 0 X 0.988 83, Whole Powder U U u u 0 u 0.980 0, Ten 8 X X U u 0 0 1 .0 3 8 2. Ten 4 X X X u u u 1.088 3. BATTELLE MEMORIAL INSTITUTE Protected Document-Subjectto Protective Order II JNJAZ5_M00010*1 15 MOISTURE CONTENT 0 considerable importance to the lubricity of talc ie its m oisture content. This topic is m ore thoroughly tre a te d in a forthcom ing re p o rt. It is im portant, how ever, to note here that an increase in m oisture content slows the descent of the puck on the lubricity board and falsely indicates superior lubricity. All of the Italian talc was found to contain a m oisture content in the hundredths of one p er cent. Analyses of various .sise fractions show that the m oisture content is higher in die fine sizes, possibly due to adsorption on the g reater surface area. MEASUREMENT AND CORRELATION OF OTHER P H Y S I C A i ' ^ ^ ^ f S ^ 'ia X A tii! ^ ' f g LUBRICITY Surface A rea Determinations by Nitrogen Adsorption The relationship of lubricity,to p a rticle -size distribution has been shown to be a m atter of friction and surface area, the finer platelets having the g reater surface area p e r unit of weight. Four samples of Italian talc from Cranford were m easured for their surface area using the B ruaauer, Em mett, Toller technique of nitrogen adsorption at liquid nitrogen tem p e ra tu re s (Table 11). TABLE 11. SURFACE AREA MEASUREMENTS OF ITALIAN TALC, COM PARED WITH LUBRICITY-BOARD MEASUREMENTS Cranford Sample Date L u b ricity -B o ard M easurement, seconds BET Surface Area M easurement, m 2/g 9-6-56 9-12-56 9-19-56 10-4-56 . 1.083 1.030 1.028 0.982 3.57 3.18 2.93 2.26 The tests show a relationship between surface area and lubricity, the sam ples with the greater surface area also having the larg er lubricity m easurem ents. The values are believed to be accurate to within 5 p er cent. Average Diameter of P articles An easily operated instrum ent for rapid p a rticle -size determ inations is the F isher Subsieve Sizer. The instrum ent m easures average particle size by determining the resistan ce to the flow of a ir by a weighed sample of powder under standard packing con ditions. On the b a sis of the principle that a fluid m eets less resista n c e to How while BATTCUr MEMORIAL INSTITUTE Protected Document-Subjectto Protective Order 16 TABLE 12. COMPARISON OF THEORETICAL AVERAGE-DIAMETER MEASUREMENTS AND SPECIFIC SURFACE TO LUBRICITY BOARD MEASUREMENTS OF CRANFORD SAMPLES Cranford Collection Date 9-6-56 11-6-56. 9-12-56 9-19-56 10-18-56 8-10-56 9-27-56 8-28-56 10-29-56 10-4-56<a) 8-20-56 10-12-56 12-22-56 11-30-56 11-15-56 Lubricity-Board M easurement, seconds 1.083 1.053 1.030 1.028 1.025 1.021 1.017 1.007 1.006 0.932 .971 0.968 0.965 0.952 0.936 Theoretical A verage^) P article Diameter 2.60 2.65 2.60 2.45 2.60 2.80 2.80 2.75 2.80 3.30 2.90 2.90 3.10 .3.30 3.20 Specific Surface, cm^/g 8392 8233 8392 8905 8392 7792 7792 7934 7792 6612 7524 7524 7038 6612 6818 (a) See comment under "Particle Size Distribution in Italian Talc", dO Detetrataad oc Fish Subsieve Sizes. battelle m em orial in st it u t e Protected Document-Subjectto Protective Order JNJA2S5_0000010S3 17 penetrating a bed of coarse p a rticle s than dille penetrating a bed of fine p a rticle s, a figure is derived which disregards the shape of the individual grains, porosity, size distribution and other v a ria b le s. Inasm uch &s the average d iam eter figure re p re se n ts a theoretical sphere, the data are of relative rath er than actual value. Average diam eter m easurem ents m ade on the F ish er Subsieve Sizer ar shown in com parison with lu b ricity m easurem ents (Table 12), dem onstrating die co rrelatio n of sm all average diam eters to talc with the larg er lubricity m easurem ent and larg er average diam eters to talc with the'low er, less desirable, lubricity m easurem ents. A cle a r-c u t c o rre la tion of the theoretical average-particle-diam eter m easurem ents with the lubricityb o ard m easu rem en ts is shown in Table 13. TABLE 13. RELATIONSHIP OF LUBRICITY-BOARD MEASUREMENTS TO THEORETICAL AVERAGE DIAMETERS ON SIZED FRACTIONS OF ITALIAN TALC Tyler Mesh Sizs L u b ricity -B o ard M easurements, seconds Unseparated +200 -200+250 -250+270 -270+325 -325+400 -400 0.990 0.889 0.951 0.980 1.030 1.043 1.099 (a) Determined oc Fiiher subsieve Sleet. Theoretical Average P article Diameter, m icrons^ 2.60 7.40 3.60 2.50 2.35 2.25 2.10 Specific Surface Calculated From Average Diameter The average particle diam eter as determ ined on the F isher Subsieve Sizer may, by use of a sim ple equation, * be expressed in term s of specific surface in square centim eters p er gram of dry powder. This is a sim pler, less expensive method than nitrogen adsorption.* *Specific su rfa c es, -ap calculated from the a v e ra g e -p a rtic le d iam e te r m ea su rem e n ts, a re p rese n ted in. Table 12 in com parison w ith lu b ricity . The calculated specific- surface figures, because of their derivation from average-particlediam eter m easurem ents, are inversely correlative with particle size. The samples with the g reater specific surfaces are thoee which impede the slide of the puck on the lubricity board, and which have better slip, while the samples with the sm aller specific surfaces, those containing the larg er particles, are the sam ples perm itting faster descents of Ihe puck on the lubricity board. As in the case of the average particle-diam eter m easurem ent, the specificsurface calculations re p re s e n t th e o re tic a l sp h eres which*, since the powder is composed of platelets, a re of relative rath er than exact value. W hereas the surface a rea aa de term ined by gas adsorption is relatively exact, the value of the aurface-area figures derived from the theoretical average-partid e-d iam eter m easurem ents is purely com parative.__________ _ Specific su rfa c e (c m S /g ) = --------- --------- 8 1 0 4 average diameter $ ) * specific gravity of talc BATTELLE MEMORIAL INSTITUTE Protected Document-Subject to Protective order JNJAaSJWOtKKOM 18 The relationship of specific surface to the lubricity of vised fractions of Italian talc is p rese n ted in Table 14, which shows that the fractions with the b e tte r lubricity also have the greater surface areas. i. TABLE 14. CORRELATION OF SPECIFIC SURFACE AND LUBRICITY-BOARD MEASUREMENTS OF SIZED FRACTIONS OF ITALIAN TALC Tyler Mesh Sise U nseparated 4200 -200+250 -250+270 -270+325 -325+400 -400 L u b ricity -B o ard M easurements, seconds 0.990 0.889 0.951 0.980 1.030 1.043 1.099 N Specific Surface, cm */g 8392 2948 6061 8727 9284 9697 10390 Porosity A m easu rem en t of p o ro sity , independent .of the other m ea su rem e n ts, m ay be made on the F isher Subsieve S iser. The porosity figure represen ts the ratio of voids to the total volume of the packed sam ple, in a range of 0.40 to 0. 80. Inasmuch as p a rt of the te s t involves a m anual operation, the re su lts a re subject to a human e rro r. The porosity figures, however, are reproducible through the second decim al place. The range in porosity, 0.448 toO . 490, determ ined on the Cranford sam ples, is a relatively sm all range and should, by its close lim its alone, be of assistance in evaluating Italian talc (Table IS). The m ore porous powders, those with the g rea test amount of asym m etrical, platy grains, are also those with the larg er lubricity-board m easurem ents, hence the b etter slip. Correspondingly, th sam ples with tie lower porosity, those containing the greater, amount of equidimensional grains, are the powders which have the low er lub ricity -b o ard .me asurem ent s . Table 16 shows the. po ro sity of aised fractions of Italian.talc as com pared with its lubricity-board m easurem ents. The porosity is d e a rly shown to be less in the coarser fractions with the poorer alip and g reater in the finer fractions. M T .T C L'Lt MEMORIAL INSTITUTE Protoctod Document-Subjact to Protocflva Older JIMAZSSJKW001056 19 TABLE 15. POROSITY, BULK DENSITY, AND LUBRICITY OF CRANFORD SAMPLES Cranford. Collection Date 9~6-56 11-6-56 9-12-56 PorosityRatio 0.490 0.480 . 0.475 Bulk Density, lb/cu it 22.942 22.958 23. 259 L u b ricity -B o ard M easurements, seconds 1.033 1.053 1.030 9-19-56 10-18-56 8-10-56 9-27-56 8-28-56 10-29-56 10r 4-56(*> 8-20-56 10-12-56 12-22-56 11-30-56 11-15-56 0.456 0.452 0.460 0.464 0.470 0.461 0.475 0.460 0.455 0.452 0.448 0. 450 23.437 22.860 23.528 23.096 22.642 22.491 24.061 23.756 23. 429 22. 616 22.725 22.583- 1.028 1.025 1.021 1.017 1.007 -1.006 0.982 0.971 0.968 0.965 0.952 0.936 (*) See com m ent a n d "P inic]~Slze Distribution in K alian T ale", BATTELLE M tM O K IU INSTITUTE Protected Document-Subjectto Protective Order JNJAZSSJM0M1M 20 TABLE 16. CORRELATION OF POROSITY AND LUBRICITYBOARD MEASUREMENTS OF SIZED FRACTIONS . OF ITALIAN TALC Tyler Mesh Sine Unseparated +200 -200+250 -250+270 -270+325 -325+400 -400 Lubricity-Board M easurements, seconds 0.990 0.889 0.951 0.980 1.030 1.043 1.099 P orosity Ratio 0.448 0.401 0.426 0.439 0.446 0.442 0.455 Balk Density The. bulk density of ground te le m ay be m easu red on a Scott V olum eter. The C ranford talc sam ples w ere found to have bulk densities ranging betw een 22 and 25 pounds p e r cubic foot. Table 15 lis ts the bulk densities of the C ran fo rd talc sam ples. The bulk-density m easurem ent is not precise enough to accurately compare sm all differences but is valuable in establishing a range of acceptability. When sined fra c tions are tested, the bulk density is seen to have inverse relationships with porosity and specific surface and to have a d ire c t relationship with average particle sine. Thus, as shown in Table 1?, bulk density is inversely correlative with lubricity as a function of particle sine. The co arser fractions, with poorer slip have the higher bulk density; the finer fractions having the lower bulk density. The relationship of bulk density, m oisture content, and lubricity is presented in a forthcoming report. TABLE 17. THE RELATIONSHIP OF BULK DENSITY TO LUBRICITY-BOARD MEASUREMENTS OF SIZED FRACTIONS OF ITALIAN TALC Tyler Me eh Size L u b ricity -B o ard M easurements, seconds Bulk Density, lb/cu ft U n separated +200 -200+250 -250+270 -270+325 -325+400 -400 0.990 0. 889 0..951 0.980 ` 1.030 1.043 1.099 23.030 34. 261 26.645 20.721 19.335 19.139 16.894 BATTELLE MEMORIAL INSTITUTE Protected Document-Subject to Protective Older JNJA2S6_000001067 21 CONCLUSIONS Because this study represents but p a rt of the picture of evaluating acceptable talc by m eans of its physical properties, it is not possible to state final conclusions without qualifications. Several relationships between physical properties, however, have been established for acceptable Italian talc and the range of their variations have been m easured. A forthcoming rep o rt including studies of other physical properties will add to the picture and will indicate the course to follow for benefieiation of the Italian talc in o rd er to improve its physical properties. The physical p ro p erties of the Italian talc sam ples have been m easured and the following ranges in values were obtained: (1) Contamination: fro m le ss than 1 to m o re than 3 p e r cent. (2) C rystallographic habit: m o re o r le s s constantly 90 p e r c e n tp laty , 10 p e r cent fib ro u s. (3) L ubricity -b o ard m easurem ent: from 0.936 to 1.083 seconds. (4) The ra tio of voids to total volume: fro m 0..45 to 0. 49. (5) T h eo retical average p a rticle diam eter: fro m 2. 45 to 3.30 m icrons. (6) Bulk density: fro m 22.49 to 24.06 Ib s/cu . ft. (7) Specific surface: fro m 6612 to 8905 em ^/g. (8) M oisture content: hundredths of one p e r cent. (9) P a r tic le -s iz e distribution: 4200 m esh -200+325 m esh -325+400 m esh (38 m icrons) -38 m ic ro n s + 30 m icrons -30 m ic ro n s + 15 m icrons -15 m icrons 0.47 to 1.22 p sr cent 3.42 to 8.30 6.77 to 10.33 40.02 to 65.72 10.23 to 22.08 10.78 to 18.23. P hysical m easurem ents on sized fractions of Italian talc showed the coarser particle fractions to have low er, le ss desirable, m easurem ents on the lubricity board and the finer fractions to have the larg er, m ore desirable, m easurem ents. The sized fractions with the preferable lubricity w ere found to have the higher porosity and specific surface and the s m a lle r p a rtic le size and-bulk density (Table 18). Lubricity-board studies on Italian talc fabricated to particular size distributions show that the lubricity is controlled by the relatively sm all amount of comparatively larg er grains in an otherw ise finer m ixture. Lubricity-board studies also show that the lubricity of the Italian talc m ay be improved by the rem oval of the co arser size fra c tions. This is not a simple m atter, however, as it involves the -variation in size of the abrasive particles. BATTEL.LE MEMORIAL INSTITUTE Protected Document-Subject to Protective order JNJAZSSJWOOOIOU o o sO .rt :3 -(Hv) t~ Umft O' m 4O1' wi h So N *n %No S S o u 3 .3 S 3 3 3 oei fc M 3 3 fN8> 3 Ss sO' So O fa tt >* s 9S s $ IQ e p4 M MM N M e-4 3O' 3 un * O' 3 O' 3 3S o . o. o o o O pH o4 04 V (.a0 0 J9 a rS U Ntf) s iS*t I 3 1* a le 1P S4- f 8 1 i SATTELLE MEMORIAL INSTITUTE Protected Document-Subject to Protective Order JNMZW_00000106a 23 sad 24 M easurem ents on flotation products show 'that the rem oval of the sm all p er cent of contaminants im proves the lubricity of the talc < The physical properties of the Italian talc can be improved, with the'least possible loss of sam ple, by rem oving the m ineral contaminant from either the coarse fractions o r from the sample as a whole. This appears to be one clear cut course to follow in improving the Italian talc. (The original notes on the laboratory work described in this rep o rt are in Battelle L aboratory R ecord Books No; 12667, pages.1 thtough 71, and No. 13034, pages 1 through 77. The work was done in the period from November 7, 1956, to Septem ber 30, 1957.) BIBLIOGRAPHY (1) S c ia r, C. B . , e t a l . , "A Review and A ppraisal of the L ite ra tu re on Talc D eposits of the United S tates", B attelle Report to Johnson and Johnson (May 11, 1955). (2) S ciar, C. B . , e t- a l., "An Investigation of Selected Talc D eposits of the United S la te s", B attelle R ep o rt to Johnson and Johnson (F e b ru a ry 29, 1956). (3) Sm ith, W. L ., and Snider, R. H ., "Investigation of the Salgada and C ase Nova Talc D eposits of Brazil'.', B attelle R eport to'Johnson and Johnson (May 28, 1957). (4) Sm ith, W. L . , L e tte r R ep o rt to Johnson and Johnson on the T alc D eposits of Madoc, Canada (July 25, 1957). W LStrr battelle MEMORIAL I N T 1 .T U T E Document-Subjectto Protective Order JlWAZ_00M01MO APPENDIX A DESCRIPTION OF LUBRICITY BOARD AND TECBBnQgB OP OPERATION BATTELCE MEMORIAL INSTITUTE oteeted Documcnt-Subiect to ProtacHv Order JNJASiJDOOOOIOei A -l and A-2 APPENDIX A DESCRIPTION OF LUBRICITY BOARD AND TECHNIQUE OF OPERATION The experim ental device described as the lubricity board in this report consists o a wooden plane inclined a t 25 'degrees, which i s lightly, but com pletely, covered with talc. The lub ricity is determ ined by m easuring the tim e it takes a steel puck to slide over two m icro switches which actuate an electric tim er. The inclined plane is made of 6-ply birch plywood, 3/4 inch thick, 6 inches wide, and 6 feet long. The even-grained wood was sanded smooth to prevent the grain from influencing the descent of the puck. Twenty-five degrees was selected as the inclination from horizontal after much experimentation which showed it to be the minimum angle at which a sustained slide could be made on all of the Italian talc sam ples. The m icrosw itches are located 6 inches from each end of the slide, in the middle of the board, making the m easured path a length of 5 feet. The m icrosw itches a re con nected to a double-pole, 115-volt, S truthers-B erm lock-in relay which actuates a Standard E le c tric T im e Company e le c tric tim e r. The steel puck weighs 226 g r a m s , is 3/4 inch by 2 -1/2 inches, has rounded edges, and presents a circular sliding surface of 1 -3/4 inches diam eter. Such are obtainable from am usem ent equipment distributors as a piece used in the game of Am erican Shuffleboard. One flat surface of the puck was ground smooth and polished for the lubricity experim ents. The talc is applied to the lubricity board from a 9-ounce Johnsons1Baby Powder can until a thin even layer is present over the m easured path. The puck is m anually released from a dead sta rt from the top of the slide, 6 inches above th e'first m ic ro switch. F or purposes of eliminating erro rs of freak descents, lubricity is m easured as the av erage of'50 runs. The b e a rd 'is newly covered with ta le a fte r each 10 r u n s , although no difference in lubricity m easurem ents could be accounted for between those early and late in a series. The puck was washed in warm water and thoroughly dried between runs. 1 Protected Document-Subject to Protective Order NSTITUTE APPENDIX B PROCEDURE FO R PARTICLE-SIZE ANALYSIS I a Protected Docum ent-Subject to Protective Order JNJAZWJXKMOIOM B -l APPENDIX B PROCEDURE FOR PARTICLE-SIZE ANALYSIS la a previous report to Johasoa and Johnsonfrom B a tte lle ^ a procedure for sizing Italian talc was outlined. F o r purpose's of the present investigation, the follow ing procedure was developed by D. A. Jacobs of the B attelle staff. One hundred g ram s of talc is w et screen ed at 325 m esh w ith w ater. The +325 m esh product is d rie d and d ry screen ed on a Ro-Tap fo r 30 m inutes producing +200, 200 x 325, and -325 m esh fra c tio n s. The -325 m esh fractio n of the dry screening is combined with the -325 m esh product of the wet screening. A suspension of -325 m esh m ate rial-is allowed to settle through a 10-centim eter column in a 4 -liter beaher to which sodium silicate has been added in the amount of 1 pound per ton, and agitated for a p e rio d of 10 m inutes. The sodium silic a te is added to the f i r s t 30-m inute settling of each sample only. At the end of the firs t 30-minute cycle, the supernatant column of liquid is siphoned off. This liquid contains the -15 m icron fraction. F our cycles are required to rem ove the -15 m icron fraction entirely, Another series of 4 cycles with settling tim es of 5 m inutes produces the 15 x 30-m icron fra c tio n , Which is siphoned off, plus sands of 30 m icrons x 325 m esh. The sands a re d ried and d ry screen ed at 400 m esh on a R o-T ap f o r 30 m in u tes, producing 325 x 100. m esh and 400 m esh x 30 m icron, fractions. The sizing flowsheet is presented as Figure B -l. I Protect! Document-SuW ectlo Protective Order MEMORIAL INSTITUTE JNMZSSJM0M1M4 * B-2. column depth 10 centimeter Settle for 30 minute, 4 cycle 1 Supernatant, >15 micron i Send Settle for 5 minute,. 4 eyelea I Superna*Jint, 15 x 30 micron Sand,. 30 micron x 325 meah Dry Dry screen at 400 mesh (o-Tap for 30 minute) 325 x 400 mesh 400 mesh x 30 microns (3S microns) FIGURE B - l . STANDARD FLOWSHEET FOR SIZING OF TALC SAMPLES attelle MEMORIAL INSTITUTE Protected Document-Subject to Protective Order NJAZW_0000#1M5