Document eo5GkjZaY0v7677x4j8gKQje

FILE NAME: Johnson & Johnson (JAJ) DATE: 1958 May 9 DOC#: JAJ030 DOCUMENT DESCRIPTION: Report - Further Studies on the Measurement and Correlation of the Physical Properties of Talc Presented to J & J Sftii MMZWSJD0MQ0M5 Protacted Document-Subject to Protective Order fNJAZSSJXXWOOSM PROGRESS REPORT cm FURTHER STUDIES ON THE MEASUREMENT AND CORRELATION OF THE PHYSICAL PROPERTIES OF TALC to JOHNSON AND JOHNSON 4&Au J f May,9, 1958' by W. L. Smith BATTELLE MEMORIAL INSTITUTE 505 King Avenue Columbus 1, Ohio Baitolle i* noi engagod jn rateerei far aivtttidng, aalo* promotion, er pubiicity purposx. and tMa fqwrl moy noi ho topmduced In filli er in par* far enei parpasea. Protected Docum ent-Subject to Protective order JNJAZ85JM0M0S07 K-3262-2 O K 'd before typing by R. D. Macdonald fo r O. F . Tangel and A. C. R ichardson, cc: Smith (3) R. D. Macdonald Files U@^T. Tangel (3> a. C, Richardson D itte tte M e m o r ia l fo s M ffte S OS KINS AVENUE COl.UHBUS I, O H I O July 18, 1958 O r, W. H. Lycan D irector of Research Johnson and Johnson^ New Brunswick, New Jersey Dear Dr. Lycan: This lette r transm its six copies of our report "F urther Studies on the M easure ment and Correlation of the Physical Properties of Talc". This rep o rt, plus that of October 25, 1957, dem onstrates that lubricity m ay be Improved and abrasiveness lessened by the rem oval of the m ineral contaminants from talc. A minimum number of physical-property m easurem ents are recommended as important in the comparison of.hlgh-grade talcs and in the evaluation of improvement of physical p roperties through beneficiation. B ecause of urgency .on other phases of B a tte lle 's investigation of talc, fu rth e r studies on the physical properties are'postponed. We would be pleased to have your com m ents on our findings. Very truly yours, WLS/djo Ene. (6) Wm. L. Smith Principal Geologist . M inerals Beneficiation Division D E D I C A T E D TO THE A D V A N C E ME N T OF S C I E N C E OKdsr JNJAZn_MOOOOM8 TABLE OF CONTENTS Page ABSTRACT ................................................................................................................................... 1 INTRODUCTION AND SUMMARY........................................................................................... 1 DISCUSSION OF ABRASIVENESS ........................................................................................... 3 THE MEASUREMENT OF ABRASIVENESS.......................................................................... 5 D i s c u s s i o n .......................................................................................... The A brasion Machine ..................................................................................... . 6 The A brasiveness of T alc S a m p l e s ......................................................................... 12 THE RELATIONSHIP OF ABRASIVENESS TO PARTICLE-SIZE DISTRIBUTION AND CONTAMINATION........................................................................................................... 14 D i s c u s s i o n ...................................................................................................................... C orrelation of A brasiveness With P a rticls-S ias D istribution and C ontam ination................................................................................................................. MEASUREMENT AND CORRELATION OF OTHER PHYSICAL PROPERTIES . 14 14 18 M oisture C o n t e n t ........................................................................................................... 18 A bsorptive P o w e r ....................................................................................... A l k a l i n i t y .......................................................................................... Acid Solubility ................................................................................................................. 22 REFLECTANCE AND W H IT E N E S S ......................................................................... D i s c u s s i o n ........................................................................................................... The M easurem ent of Reflectance and W h ite n e s s ................................................... 27 THE DUST C O M P O N E N T ...................................................................................................... 28 APPRAISAL OF PHYSICAL-PROPERTY MEASUREMENTS IN THE EVALUATION O F ORES AND BENEFICIATION P R O D U C T S .................................. 30 FUTURE W O R K ....................................................................................................................... 33 R E F E R E N C E S ............................................................................................................................. 33 APPENDIX A DESCRIPTION OF ABRASION MACHINE AND TECHNIQUE OF OPERATION . . A -l APPENDIX B DETERMINATION OF EQUIVALENT DOLOMITE CONTENT IN ITALIAN TALC BY VOLUMETRIC ANALYSIS......................................................................... BATTELLI MEMORIAL INSTITUTE 5 20 21 23 23 B -l Protected Document-Subjectto Protective Oder JNJAZSfjraOOMSOB FURTHER STUDIES ON THE MEASUREMENT AND CORRELATION OF THE .PHYSICAL PROPERTIES OF TALC by W. L. Smith ABSTRACT To estahliih the Interrelationships of tko physical propm ils oftalc ani tobo oblo to dooolite the maone of tketr Improvement, It hoe been uecessary to devise maone of mecsurlng amali differences in properties. To determino the nature and affecte of p it, a chemical analysis far email concentrations of carbonate minerait and a machine for measuring A s rslotiot obrotlveoeee of tele samples were contrived, and the measurements were compared with these of other physical propertiee. The varient other measurements were made on ttandard laboratory Instrumente, using both deed fractions and whale powder. PhyiicaUproperty measurements of A t tale demonetrated that the eamples which produced A t least abrasion were Aeoe with the greater platy tale component and those with the least amount of contaminante. It Is concluded that As improvement of slip and the lettering of abrasiveness may be aecempiiehed by A t removal of Ao mineral contaminants, but not by A t removal of site frottions. Preliminary work en coler and reflectance properties is presented, and demonstrates o relationship te particle site and, hence, secondarily to other physical properties. The report includes on appraisal of the various physical-property meas urements employed in the evaluation of improvement of tales. A miriaua number of measurements are recommended oe ImportantIn the consideration of btneflclotion for Improvement and for comparison of naturel high-grade ores. INTRODUCTION AND SUMMARY This report Is a continuation of the studies of the physical properties of talc, th e ir m easurem ent, and c o m p a riso n '1)*, previously reported to Johnson and Johnson. The first P rogress Report dealt with petrography, lubricity, and such physical m eas urem ents as average diam eter, bulk density, porosity, and surface a re a . It was con cluded from the previous study that the acceptable Italian, talc fell within a sm all range of physical m easurem ents and that the samples with the m ore desirable slip have the g reater surface area, the sm aller average particle diam eter, the g reater ratio of voids to total volume, and the le sse r bulk density. Lubricity was found to be controlled by the shape of the relatively sm all content of larger particles in an otherw ise finer mix ture. Removal of the coarser contaminants, or preferably of all of the contaminants, was concluded to be a means of improving the slip of the talc. ' RefttMttt appeal at end of tepe. (ATTILLI MEMORIAL INSTITUTE Protected Doeumerrt-Sutyeet to Protective Order JNJAZ55 2 The conclusions o the previous progress report have been further substantiated by the following studies; however, since lubricity is but one of many of the properties of talc, the previous work represented but p art of the picture. W hereas the previous report dealt prim arily with the physical m easurem ent of areaB, diam eters, weight, and directly related characteristics, this report deals with reflectance, color, m oisture content, ab rasiv en ess, alkalinity, and acid solubility --p ro p erties related to lubricity only through th eir common correlation through surface area, size, and component co ntam ination. As in the previous report, both particle size and shape and the amount and nature of the contaminants are investigated to determ ine the contributing factors to physical m easurem ent variations. It is recommended as & resu lt of these studies that the following m easurem ents a re sufficient to determ ine satisfactory talc within the range in composition of Italian talc- These a re the determ ination of the m ineralogy and p article size distribution, volum etric analysis of the carbonate component, and the m easurem ents of ths bulk density, m oisture content, reflectance, and whiteness. This should also serve as a basis for the determ ination of acceptability in other talcs and beneficiated products, taking into consideration the differences in size distribution, crystallographic habit, and m ineral contamination. Because size distribution, as it is reported, is .dependent upon the analytical procedure, the m easurem ent of physical properties is made only on closely sized fractions in the co arser size ranges. Division into size fractions of the finer size p o r tion of a powder which is composed of platelets is inaccurate by standard laboratory procedures and requires detailed petrographic examination of the products. A method proposed by R. W. S ch atz^ ) which rep o rts size distribution on the basis of th eo retical spheres rath er than on the basis of actual petrographic m easurem ent serves as an ex cellent comparative m easurem ent for powders with sim ilar m ineralogical and cry stal lographic composition. Of necessity, these figures show little resem blance to the m easurem ents of the greater dimensions of the talc platelets. Consistent with the previous progress report, the particle-size-distribution data here presented are based on screened size fractions and the sizes given a re those m easured os a petrographic microscope. As in the study of lubricity, in order to determ ine the improvement of specific physical properties, objective tests had to be devised to m easure the sm all differences between acceptable talc and talc of lower quality. Until now, acid solubility was determ ined g ravim etrically on the various talc sam ples. The sm all differences in p e r cent composition and per cent incidence of the carbonate component of Italian talc, and .its close relationship to both abrasiveness and lubricity, required the development of an analysis for equivalent dolomite in low concentrations (Appendix B). A brasiveness has previously been m easured subjectively, sim ilar to lubricity. However, because subjective m easurem ents are not correlative, and because small, often significant differences cannot be so m easured, an abrasion machine was built. This device, does not give an absolute value to abrasion, however, it provides rep ro ducible figures which a re of relative value and which are correlative with m easurem ents of other physical properties. Except where otherwise not$d, the m easurem ents presented in this report .were made on the sam e sam ples of ''E S f1E xtra 00000" talc, obtained from the Cranford, New Jersey, plant, which w ere used in the work reported in the previous P ro g ress R eport on physical p ro p erties. BATTELLE MEMORIAL INSTITUTE Protected Document--Subject to Protective Order JNJAZ55JXI0000911 3 DISCUSSION OF ABRASIVENESS A highly undesirable property of a talcum powder is abrasiveness or grittiness. G rit is undesirable in that it may scratch or otherwise irritate the skin, and even very sm all amounts of g rit may quickly be noticed subjectively. G rit consists of that portion of ground talc which is angular, or oversize, p a r ticularly in thickness. G rit includes both oversize and nonplaty talc particles as well as m ineral contaminants. It occurs as aggregates of talc and contaminants, as acicular and fibrous particles of tale and amphibole, as shards and granules of amphibole or carbonate, and as prism atic grains of tit&nite, rutile, zircon, apatite, and other accessory m inerals. Where the grit is other than oversize talc, it has hardness and angularity suffi cient to scratch. Talc which is oversize in its greater dimensions is ra re in the. samples studied. It is the product of incomplete grinding and may easily be removed on a 150-mesh screen . Talc which is oversize in thickness is of the nonplaty variety, the resu lt of the incomplete alteration of pre-existing m inerals or the form ation of pseudomorphs after m ore equidimensional species. Such particles serv e less as ab rasiv es than as d e te rre n ts to p roper slip. The 8 to 10 p er cent of nonplaty talc in the Italian m aterial is presum ed to be derived from trem olite or enstatite. This mechanism is discussed in the reports on the B razilian ^ ) and Canadian^) talc deposits. Whereas friction, as expressed in the sense of the translation movements of talc platelets over one another, produces the desirable property of slip, such friction is not a disruption of the free lam ellar movement of the component particles of the powder nor a disruption of the free movement of the surfaces in contact, When, however, a lu b ri cant fails to m ask irregularities in the contacting surfaces or introduces asperities of its own, then point friction or plowing is initiated. Point friction and plowing are the sources of irrita tio n o r g rittin e ss. G rit perm its w ear between the contacting su rfaces by abrasion, either in the plowing or scratching m echanism of oversize and angular particles, or by the disruption of lam ellar movement of the platelets which leaves areas unlubricated or introduces a damming -up and rolling of particles. Although lubricity and abrasiveness may seem to be relative, or the presence of one may seem to preclude the p resen ce of the other, no d ire c t c o rre la tio n should be expected between the two p ro p erties inasmuch as both a re the functions of several variable fac to rs. A d e c re a se in g rit, however, is c ertain to im prove the lubricity of whole powders where particle size is not a controlling factor. Idealized talc particles a re rounded platelets which may be thought of as e ssen tially two dim ensional, the thickness being about 1/8 to l/1 5 of the g rea ter dimension, depending upon the crystalline nature of the m ineral and the degree of subdivision attained. In the b etter grades of talc the greater dimensions of a platelet a re nearly equal. The Italian No. 1 talc contains from less than 1 per cent to about 3 per cent of contaminants. The contamination is natural and consists mostly of carbonate with minor amphibole and ra re accessory m inerals. The carbonate component has been identified petrographically as p rim a rily dolom ite (CaO* MgO* 2CC>2) plus a m inor amount of probable m agnesite (MgO* C 02). No caicite (CaO* COt) was identified. The amphibole component has been established to be the v ariety tre m o lite (2CaO- 5M gO SSiOj' H2O). battelle memorial institute Protected Document-Subject to Protective Order JNJAZ56_000000912 4 Table 1 based on Table 2 of the previous P ro g re ss R eport!1) lis ts the incidence of con tam inants in the Cranford sam ples. Table 2 shows the distribution of the m ajor con tam inants in the different size fractions of Italian talc. TABLE 1, PREVIOUSLY REPORTED!1) PER CENT CONTAMINATION IN TALC SAMPLED AT CRANFORD, NEW JERSEY Incidence of Contaminants (s), per cent <1 1 1- 2 2 2- 3 .... Date Sampled 's 9-6-56, 9-12-56, 9-19-56 8-10-56, 9-27-56, 10-18-56, 11-6-56 10-4-56, 10.-29-56 8-20-56, 8-28-56, 11-15-56, 12-22-56 10-12-56, 11-30-56 (a) Determined petrographieslty. TABLE 2. THE DISTRIBUTION OF THE MINERAL CONTAMINANTS IN THE DIFFERENT PARTICLE-SIZE FRACTIONS OF ITALIAN TALC Tyler Mesh Size Unseparated +200 -200+250 -250+270 -270+325 -325+400 -400 Incidence of Contaminant Total Dolomite 2 <2 <1 <1 1 1 1-2 1-2 2 2 2 2 >2 >2 per cent Trem oli te Trace 0-trace 0-trace Trace Trace Trace 1 <1 (a) Incidence determined penographicaliy. G rit is p resen t in till size fractions, being somewhat m ore abundant in the fines. In the coarser fractions the m ineral contaminants and the talc p articles which a re o v er size in thickness a re m ost readily sensed subjectively. The presence of grit in the fines is largely m asked to the senses by the presence of la rg e r p latelets. In this regard no solution to,abrasiveness lies in the rem oval of entire coarse size fractions, inasmuch as the g rit in the then rem aining co arser fractions would be as readily noticeable sub jectively and more abundant percentagewise. To remove the abrasive particles, it is necessary to rem ove both nonplaty talc and the m ineral contam inants from the whole powder by such beneficiation methods as flotation!5) and classificatio n by eydoning(6), the initial studies on which have been rep o rted o r a re .in prep aratio n (Table 3). b a TT e L L e; MEM O I A V } Protected Document-Subject to Protective Order N E T I. T U T E <1NJAZ55_00Q0Q0913 5 TABLE 3, THE EFFECT ON LUBRICITY OF THE-REMOVAL OF MINERAL CONTAMINANTS AND NONPLATY TALC FROM ITALIAN TALC SAMPLES Talc Sample Italian No. 1 Feed Float Italian No. 2 Feed Float Incidence of Indicated P a rtic le Type(a ), p er cent Platy Nonplaty Talc Talc Dolomite Trem olite 88-90 8-9 95 4 90 5 98 <1 <2 Trace 3 Trace < 1 Trace 2 Trace L u b ricity -B o ard M easurement, sec 0.990 1.046 0. 926 1.051 (a) Mineralogia)! incidence determined petrographiclly. It is im portant to em phasise the difference between the incidence or frequency of contaminants and their per cent of total composition. The per cent incidence is d eter m ined petrographicaily by grain count. It is a tw o-dim ensional m easurem ent approxi m ating area and does not consider the thickness of the particles observed. The inci dence of a m ineral or crystal type is of prim ary im portance inasm uch as a powder consists of a m ixture of discrete grains, each with its particular size, shape, and other physical pro p erties. In onsidering the behavior of a powder as a lubricant, we are dealing with the piechanic&l interactions of individual grains in lam ellar movement and thus are concerned with the frequency of types of grains, not with their per cent of total composition. That is, for example, in considering lubricity or abrasiveness we must deal with the incidence of individual p a rticle s of dolom ite ra th e r than with the total volume otj weight p er cent of the sam ple which is dolom ite, except when dealing with closely sized sam ples. Conversely, when considering acid solubility, m oisture content, and the analysis and evaluation of beneficiation products, we, of necessity, deal with to tal com ponents' not the incidence of p a rtic le s. While sm all differences in p er cent incidence of contam inants in a powder m ay influence the physical p ro p ertie s of m echani cal movement, in no case described here is the p er cent incidence different from the weight per cent or the chemically analyzed component by more than 1 per cent of the -whole sam ple. THE MEASUREMENT OF ABRASIVENESS D iscu ssio n A standard method of m easuring the abrasiveness of high-quality talc has not been devised previously. Abrasiveness or grit has been m easured subjectively by testing sam ples between the fingers o r teeth. As in the case of lubricity, the final analysis of accep tability in re ga rd to ab rasiven ess is subjective: consum er reaction. O bjective tests are not designed to replace the subjective tests; however, to be able to determine BATTELLE MEMORI AL INSTITUTE Protected Document-Subject to Protective Order JNJAZ5S_00000091* 6 im pr ovam ent in beneficlation procedures and to determ ine the c o rre la tiv e relationships of the physical properties of tale, it is necessary to be able to m easure sm all differ- . onces in the physical properties and to be able to compare them to other quantitative m easurem ents. Knowledge of these interrelationships serves as die b a sis for in te r pretation of improvement in quality and thus serves to m ake it possible to visualize methods of bnficitiom ' \ . Since tihe'subjective te sts are of little help in m easuring sm all differences in one , of the many physical properties encountered, and since such te sts have no b asis for correlation, a machine was built to m easure objectively, o r test for, abrasiveness, apart from other physical properties, The Abrasion Machine Because it was necessary to m easure sm all differences in the abrasiveness of talc, a machine was built to test 'the w ear effect of sm all concentrations of g rit on standard m aterial. The machine was built of a 1/20-hp 1725-rpm electric motor mounted v ertically and fitted with a 5 -Inch lap covered by a B uehler M icrocloth held in place by a rubber belt. The lap portion of the machine is set into a steel bowl end covered with e plastic lid. Mounted on a ringstand over the lap a 500-ml open se p ara tory funnel with, stopcock is connected by a rubber tube with an adjustable pinch clamp to a feed spout. The separatory funnel contains the sample of talc to be tested in a s lu rry of 3 gram s' of talc to 350 m l of w ater. Tbs- feed-' spout and a cylindrical pellet holder e re mounted .in a rem ovable crossbar over the lap. A ccessibility to these parts is afforded through a hole in the plastic cover. Standard 1/2-inch-diam eter pellets are held in the sam ple holder by a 16.1 -gram weight to prevent th eir skipping or floating on the lap. A 1000-m l beaker mounted under a drain in the steel bowl catches the tested .slurry. Figure l shows the over-ell apparatus. Figure 2 shows the detail of the feed and abrdsion m echanism. A detailed description of the abrasion machine and the technique of its operation a re found in Appendix A. In order to m easure the abrasiveness of ths talc in the slu rry a test had to bs designed where the object abraded would have a great enough loss to bs m easured physically. Since the abrasiveness to bs m easured was that of a powder containing generally from only 1 to 3 per cent of abrasive gangue particles, the m aterial to be abraded had to have a hardness greater than that of the tele, less than that of the grit, and also had to be coherent and homogeneous. After testing a large number of m aterials it was decided to perform the bulk of the teste on pellets nude of minus 400-mesh Italian ta lc p re s s e d under'50, 000-psl p re s s u re . The p ellets average 5.2 0 g ram s and have dimensions of 1/2 by 7/10 inch. The pellets have a hardness greater than that of the aw talc and le s s than th at of the contaminants,{Table 4). Carbonate pellets were m ade to te s t specifically fo r the r a r e r , harder.com ponents, In a sim ilar m anner, but using alcohol instead of w ater in the slurry. IATTILL I M. E M Q. R..I A ( - INSTITUTE Protected Doeum int-SutdM t to Protective Order JNJAZM0OOOOO915 7 and 8 FIGURE 1. N 45893 THE ABRASION MACHINE SHOWING RESERVOIR CONTAINING SAMPLE IN SLURRY TO BE TESTED FOR ITS ABRASIVENESS battelle memorial institute Protected Document-Subject to Protective Order JIUAZSfi_08M0M16 Protected Documnt-8uWet!o Protecttv* Onto ATTELLE 9 and 10 MEMORIAL INSTITUTE FIGURE 2. DETAIL VIEW OF ABRASION -MACHINE LAP SHOWING FEE D SPOUT, CYLINDER IN WHICH PEL L E T S ARE HELD ON THE LAP, AND STANDARD PELLETS O F PRESSED TALC JN JA ZW JJ00000917 11 TABLE 4. RELATIVE HARDNESS OF THE TEST PELLETS AND THE GRIT PRESENT IN ITALIAN TALC M ineral Moh Hardness Talc Pressed-talc test pellet M agnesite Dolomite Pressed-carbonate test pellet Apatite Titanite T rem o lite Rutile Zircon .1 2 (scratches talc) 3. 3 (scratch es talc pellet) 4 >4 (scratches dolomite) 5 (scratches carbonate pellet) 5 6 6 . 7.5 The abrasion-m achine operation is timed electrically. The pellets are m eas ured on a m icrom eter caliper before the te s t and afterw ard, after drying. The a b ra sion m easurem ent is reported in decim al fractions of an inch p er second. Although th ere are lim itations to the use of a m icrom eter, the sam ples which w ere compared dem onstrated differences in m easurem ent large enough to be significant. M easure m ents based on weight were found to be entirely unsatisfactory inasmuch as some weight loss was due to spalling and abrasion of th e pellet by the w alls of the sam ple tube on portions other than that exposed to the lap and abrasive. This indicated losses which w ere no indication of the degree of lo ss due to action on the tested surface alone. The abrasion machine subjects the standard pellet to abrasion by the sample of talc being studied, at a high rate of speed, It has been calculated that the pellet rec e iv e s w ear equivalent to being rubbed over m ore than 1800 ft/m in of surface of the talc being tested. As expected, the abrasion machine dem onstrates that the slurry samples with the g reater incidence of m ineral contaminants produce the greater amount of abrasion on the pressed pellets. It is also shown that those sam ples with prim arily platy habit are less abrasive than those containing effective amounts of nonplaty talc. More p recise abrasion m achines could be built; however, the device used is sa tis factory for the purpose of comparing samples within the range of those tested and is an adequate means of obtaining comparable m easurem ents of the effect of grit. Typical figures obtained by the abrasion experim ents a re shown in Table 5, battelle i Protected Document-Subject to Protective Order MEMORIAL INSTITUT E JNJAZ55_000000918 12 TABLE 5. TYPICAL FIGURES OBTAINED BY ABRASION TESTS ON FOUR SAMPLES OF ITALIAN TALC Incidence of Pellet Difference in Contaminant s (a), M easurem ents, in. Mens urem ent s , Test per cent Before Alter in. 1 2 2 2 3 2 4 2 0.6453 0. 5566 0.6435 0. 5483 0. 6184 0. 5374 0.6442 0.5699 0. 0887 0. 0952 0.0810 0. 0743 Time, sec 38 41 36 32 A b rasion^)* 10- 3 in,/sec 2. 33 2.32 2.25 2. 32 (*) Determined petiogrtphleally. (b) Significa figure: 2.3 x 10"3 in./sec. Th Abrasiveness of Talc Samples Fifteen samples of talc collected at the Cranford plant of Johnson and Johnson, Use sam e sam ples used in the previously rep o rted lubricity e x p e rim e n ts^ ), w ere tested on the abrasion m achine. The resu lts of the m easurem ents a re shown in Table 6. The m easurem ents show a range of from 1.62 to 2. 69,x 10"^ in. /s e c w ear on the standard pellets. These figures are generally correlative with the incidence of contaminants, as determ ined petrographically, as reported in the P ro g ress Report dealing with lu b ricity(*). As it will be shown further in the report, this relationship only holds in whole unseparated powder where particle size is not a fundamental controlling factor. The correlation of lubricity-board'm easurem ents with contamination reported in Table 2 of the previous P ro g ress R eport^) shows a sim ilar general relationship between contami nation and lubricity. Where the lubricity experim ents concluded that the sample.* con taining the greater amount of contaminants dem onstrated the poorer lubricity, the ' abrasion-m achine experim ents show that the, sam ples with the g re a te r contamination produce the g re a te r amount of ab rasio n . Thus, when dealing wih whole, unscreened powders, the rem oval of grit should also serve to im prove lubricity. Although the rem oval of g rit improves the lubricity of whole powders, the re la tionship of lubricity to abrasiveness cannot be considered to be m athem atically inverse. The properties which control abrasiveness are th size and shape of the contaminants and their Incidence in die co arser fractions; w hereas, the properties which control lubricity are the over-all size distribution, those previously described properties directly related to surface area, plus the incidence of the coarser components, when m easuring screened fractions of powders both abrasiveness and lubricity are influenced by the specific p article size, and abrasiveness will be directly irelated'to the grit com ponent, w hereas in whole powders the finer abrasive particles will be in part m asked by the coarser platelets. To te st fu rth er the effect of contaminants upon ab rasiveness, the contaminants w ere rem oved from a sam ple of talc by froth flotation and the products were tested on the abrasion m achine. The same samples had previously been tested for lubricity U). The test resu lts, which a re noticeable subjectively, are reported In Table 7. B A TTIU I MEMORIAL INSTITUTE Protected Document--Subjectto Protective Order JNJAZE5_M0000919 13 TABLE 6. RELATION OF PURITY OF SAMPLE TO ABRASIVENESS AND LUBRICITY IN WHOLE POWDER Date Sampled 9-12-56 8-10-56 9-19-56 9*656 10-18-56 9-27-56 10-4-56 8-20-56 8-28-56 11-6-56 il-15-56 10-29-56 11-30-56 10-12-56 12-22-56 A brasive n e ss, 10"3 in. / sec 1.62 1.70 1.84 1.87 1.88 1.90 1.90 1.91 I. 97 2.15 2.30 2. 32 2. 32 2. 59 2.69 Incidane of Contaminant (a), par cant <1 1 <1 <1 l 1 1-Z 2 2 1 2 1-2 2-3 2-3 2 L u b ric ity -B o a rd M easurement, sec 1.030 1.021 1. 028 1.083 1.025 1. 017 . 0. 982 0. 971 l.*007 1. 053 0. 936 1. 006 0.952 0.968 0. 965 (a) Previously reported l>, determined petrogrtphlcaliy. TABLE 7. ABRASION AND LUBRICITY MEASUREMENTS ON FLOTATION PRODUCTS OF ITALIAN NO. 1 TALC Product A b rasiveness, 10~3 in, /a e c L u b ricity -B o ard M easurement, sec Starting sample Flos productW Nonfloat product0*) 2. 14 1. 50 (superior)(c) 3. 03 (Inferior) 0. 990 1.046 (superior) 0.873 (inferior) (a) EoentlaUy pure tele, repreaendng 90 per cent of starring am ple. <b) 85 per cent talc, 15 par cent contaminant, tnpraenttag 10 par cant of starting sample. (0 Last abrasive float products have bean made from Italian Mo. 9 tale. BATTELLC MEMORIAL INSTITUTE Protected Docum ent-Subject to Protective Order dNJAZSS_OOOWW20 U The float products clearly demonstrate superiority over the starting sample in regard to both abrasiveness and lubrioity. The deleterious effect of contaminants is shown by the inferior m easurem ents derived from testing the reject product of the flotation pro cess. THE RELATIONSHIP OF ABRASIVENESS TO PARTICLE-SIZE DISTRIBUTION AND CONTAMIMATION Discussion The abrasiveness of the talc studied is determ ined by its component grit. When dealing with the m echanics of a powder in lam ellar motion, we are dealing with the in terrelationship of individual particles, and thus a re concerned with the per cent incidence and particular sizes and shapes of individuals. The distribution of the con taminants and nonplaty talc in the different else fractions is thus a prim ary considera tion. The coarse contaminants are those which scratch and are quickly noticed sub jectively. The fin er contaminant* clog the lam ellar movement of the talc platelets and initiate rolling of the powder, introducing aggregate asperities. hi the previous rep o rts to Johnson and Johnson^* the problem of particle- size distribution h as been thoroughly discussed. It does not seem requisite here but to re-em phasize the importance of establishing the particle-size distribution of a powder when studying its physical properties or the means of their improvement. Since the size of the abrasive p articles, as well as their incidental abundance, contributes to abrasiveness, it was necessary to determine the size distribution of the contaminants. C o rrelatio n pi A brasiveness With P a rtic le -S iz e Distribution and Contamination Portions of the sam e sam ples which were used to te st for lubricity and other physical pro p erties w ere used in the following experim ents on abrasiveness. Size fractions w ere m ade of Italian talc and w ere m easured for their abrasiveness on the abrasion m achine. Results of the experim ents show that the finer p article-size fra c tions a re m ore abrasive than the cofcrse. This is in agreem ent with the incidence of grit determ ined petrographically. Chemical analyses for equivalent dolomite on these sam ples a re also in agreem ent. ThAse analyses appear in the section of this rep o rt dealing with acid solubility. - Table 8 shows the results of abrasion tests of size fractions on standard talc pellets. When comparing size'fractions a parallel relationship exists between lubricity and abrasiveness, as a function of particle size. Thus, w ere only the fines, the most lubricous fraction, used fo r baby powder, this fraction, would also be the m ost abrasive. In order to retain the m ore lubricous p articles yet rem ove the m ore abrasive, it is necessary to rem ove the contaminants only. Both lubricity and grittiness cannot be improved by the rem oval of partlcle-rsize fractions. A TTILLI M. E M q R I A ,L INSTITUTE Protected Docum ent-Subjectlo Protective order JNJAZ5SOOOOOOM1 15 TABLE 8. RELATIONSHIP OF ABRASIVENESS AND LUBRICITY TO PARTICLE SIZE AND CONTAMINATION IN SIZE FRACTIONS OF ITALIAN NO. 1 TALC Tyler Mesh Size Unseparated +200 -200+250 -250+270 -270+325 -325+400 -400 A b rasiveness, 10~3 in. / sec 2.14 1. 30 1. 59 1. 72 2. 00 2. 33 2. 48 Lubricity-Board M easurement, sec 0. 990 0.889 0. 951 0. 980 1. 030 1.043 1.099 Incidence of Contaminants (a), per cent Total Dolomite Tremolite 2 <2 Trace <1 <i 1 1 1-2 1-2 2 2 2 2 >2 >2 0-trace 0-trace Trace Trace T race-1 < 1 (a) Determined petrographically. In o rd er to show which effects a re prim ary, and which a re secondarily related because sized m aterials are analyzed, tests were made on the plus 200-mesh fraction of the talc as received from Italy, on the minus 400 -m esh fraction, and on the plus 200-mesh m aterial after it was crushed to pass a 400-mesh screen. The natural plus 200-mesh m aterial had but a trace of contaminants compared with the m ore than 2 per cent present in the natural minus 400-m esh fraction. Abrasiveness and lubricity tests (Table 9) show clearly that the ab rasiv en ess is controlled p rim a rily by the contam ina tion and only secondarily by the size fraction analyzed. It also shows that the lubricity is controlled p rim arily by the particle -size fraction tested, and only secondarily by the contamination present in the specific size range. This experiment serves as the basis of interpretation for relating the physical properties of sized m aterial, and also estab lishes the controlling factors behind lubricity and abrasiveness in whole powders. TABLE 9. COMPARISON OF LUBRICITY AND ABRASIVENESS TO DRAIN SIZE AND CONTAMINATION Sample Natural +200-mesh fraction Natural -400-m esh fraction +200-mesh fraction ground to -400 m esh A b rasiv en ess, 10" 3 in. / sec 1.30 2.48 l. L u b ricity -B o ard M easurement, sec Incidence of Contaminant s(a), per cent 0.889 1.099 1. 108(c) Trace >2 Trace (a) Determined petrographically. 0>) The abrssWeaei* of this sample U only slightly lest than that produced by the same sample prior to grinding, much leu than the natural minus 400-mesh friction which contains mote grit. (c) The lubricity of this sample Is gieatly improved by regrinding, but it is essentially like die natural minus 400-medi sample despite the difference in the grit present. BATTELLE MEMORIAL INSTITUTE Protected Document-Subject to Protective Order JNJAZ65_000000922 Protected Document-Subject to Protective Order TABLE 10. ABRASIVENESS AND LUBRICITY MEASUREMENTS OF ITALIAN TALC SAMPLES FROM WHICH SPECIFIC PARTICLE-SIZE FRACTIONS HAVE BEEN REMOVED o > X R epresents Fractions Removed F ro m Whole Powder -I U Represents Fractions Tested H PI Incidence of Lub ricity -Boar ) r Contaminant sW , M easurem ent of Abrasivenes s r Tyler Mesh Size per cent t Size F ractions, sec 10-3 in. /s e c T e st 1 T est 2 Whole Powder Test 3 T est 4 n +200 d z -200+250 : 1 m -250+270 1-2 z -270+325 ' 2 o -325+400 2 a -400 >2 0.889 0.951 0,980 1.030 1.0431.099 1.30 - U U U X X 1.59 U U U X X 1,72 u u- U u X 2.00 X u U u u 2. 33 2. 48"r X u X X U U u u 1--* u u. O' > r Lubricity-Boa rd Measurement, sec 0.945 0.963 0.990 1. 038 1.068 -Increase in slip and abrasiveness ------- ^ z Abrasiveness, 10 - in. / sec 1. 88 1.88 2.14 2. 27 2.34 Approximate Weight - "* P e r Cent of -c Fractions Removed I* T-'------------------- ;--------------------------------- (a) Determined petrographicallyi (b) Based on Table 10 of previous r e p o r t ^ . 97. 0 82.0 0.0 -2.0 3.0 JNJAZS5 17 In the previous study of lu b ricity (l), m easurem ents w ere made on powders from which different size fractions had been removed, and on m ixtures of specific size fractions. The experim ent demonstrated that the over-all lubricity was influenced prim arily by the co arser particles. Similar experim ents on abrasiveness have been made and show that it is not possible to increase the lubricity by removing total size fractions without increasing the abrasiveness (Table 10). Because talc contains trem olite and ra re accessory m inerals as well as carbonate as abrasive components, a test was devised to m easure the abrasiveness of the harder contam inants. Carbonate pellets w ere made by fusing a th ree-to -o n e m ixture of sodium carbonate and sodium borate into a m elt. The fusion product was crushed and pressed into pellets under 15, 000 p si. The resulting pellets w ere h a rd e r than the talc or the carbonate contaminants but softer than the trem olite and accessory m inerals. The pel lets were slowly soluble in water; therefore, alcohol was used as the fluid in the test s lu r r ie s . The te s t re su lts a re not n ecessarily c o rrelativ e with m easurem ents m ade on talc pellets, but dem onstrate the distribution of the h a rd e r contam inants (Table 11). All other abrasive data contained in this report have been determ ined on pressed talc pellets. TABLE 11. THE DISTRIBUTION OF THE CONTAMINANTS HARDER THAN CARBONATE IN ITALIAN TALC AS SHOWN BY ABRASION TESTS MADE ON CARBONATE PELLETS Tyler Mesh Size Unseparated +200 -200+250 -250+270 -270+325 -325+400 -400 A b rasiveness (on Talc P ellets), 10-3 in, /ggc 2.1 4 1.30 1.59 1. 72 2.00 2. 33 2.48 A b rasiv en ess (on Carbonate Pellets), 10"3 in. / sec 0.9 0.5 0. 7 0. 6 0.6 0.8 0.9 Incidence of Contaminants(&J, per cent Total Dolomite Trem olite + 2 <2 Trace <1 <1 1 1 1-2 1-2 2 2 2 2 >2 >2 0-trace 0-trace Trace Trace T race-1 <1 (a) Deteimlned petioguphleaUy. To dem onstrate the effect of the r a r e r contam inants on the ab rasion of p resse d talc pellets, a series of sized fractions of Italian talc were leached free of the carbonate components and m easu red on p re sse d talc p ellets. Table 12 shows the degree of a b ra r siveness produced by the leached sam ples. a A T T c LL C m e m o r i a l Institute Protected Document-Subject to Protective Order JNJAZS5_000000924 18 TABLE 12. ABRASION TESTS USING LEACHED AND UNLEACHED SIZED FRACTIONS, DEMONSTRATING THE EFFEC T OF DOLOMITE ON ABRASIVENESS Tyler Mesh Size Unseparated +200 '-200+250 -250+270 -270+325 -325+400 -400 Abrasiveness, 10-3 in ./se c Unleached Powder Leached Powder 2.14 1.50 1. 30 1.59 1,72 2. 00 2.33 2.48 1. 34 1.60 1.72 1.71 1.90 1.75 An additional te a t, not relativ e to the beneficiation of Italian ta lc , but designed as an experim ent to serve ae a basis for study of lower grade talc , was made on a series of m ixtures of Italian talc and m inus 400-m esh calcium carbonate (Table 13). Although the data a re not to be considered co rrelativ e with.those of Italian ta lc , they dem onstrate c le a rly the. in creasin g effect of contam ination on abrasion. TABLE 13. ABRASIVENESS OF MIXTURES OF ITALIAN TALC AND CALCIUM CARBONATE P er Cent Italian Talc(a) 100 90 50 10 ` 0 P e r Cent CaO COg (-400 Mesh) 0 10 50 90 100 (a) Contains about 2 pet cent native carbon*. A b rasiv en ess, 10" 3 in. / sec 2.14 2. 89 5.09 8.17 13. 65 Difference in A b rasiveness, 10" 3 In. / sec 0. 75 2.20 3. 08 5.48 , MEASUREMENT AND CORRELATION OF OTHER PHYSICAL PROPERTIES Molsthre Content The previous P ro g re ss R e p o rt^ introduced the problem of m oisture content in talc , suggesting that the fine*grain-size fractions should adsorb m ore m oisture on its g re a te r surface a re a p e r unit of w eight Table 14 shows the m o istu re content of size fractions of Italian talc, demonstrating an increase in m oisture content with decreasing particle size. Becauee of the relationship of particle size to other physical properties, IA T T E U I ME MO. RI AL INSTITUTE Protected Docum ent-Subjectto Protective order JNJAZ55_OOOOOOI25 19 the m oisture content of the sized fractions was found to be apparently correlative with a number of other m easurem ents, indicating coincidental relationships which would not hold true in unsized samples. TABLE 14. RELATIONSHIP 0 7 MOISTURE CONTENT TO PARTICLE SIZE IN ITALIAN TALC Tyler Mesh Size Unseparated +200 -200+250 -250+270 -270+325 -325+400 -400 Per Cent M oisturs(a) 0.05 0. 01 0. 03 0. 03 0. 04 0.05 0. 06 (*) Woltiure content deieunfcied by method autUnid in iohncan end Minion's Raw Materials Specification! sheet. The lubricity of talc is related to its m oisture content insofar as the m oisture con tent of the finer fractions is higher. In lower grade talc the m oisture content was found to be much higher. Six dom estic ta lc s , fabricated to a p a rtic le -s iz e distribution sim ilar to that of the Italian ta lc , showed from 0.08 to 0. 20 p e r cent m oisture on an aly sis. The higher m oisture content of some Inferior talcs requires that m oisture be determ ined on sam ples p rio r to testing for lubricity. M oisture tends to make talc p asty , producing a false indication of superior lubricity on the lubricity board. To dem onstrate that the 0, 05 p er cent m o istu re content of Italian talc did not affect the lu b ric ity , te s ts w ere run on talc from which the m oisture had been driven off. A nonreprodudble difference of only 0. 006 second was reco rd ed , and is not considered to be a significant figure. To fu rth e r t e s t the co rrelatio n of m oisture content and p article s iz e , the talc sam ples collected at Cranford were analyzed and the data com pared with the percentage of fines in the sam ple. Table 15 com pares the m o istu re content and the percentage of the powder finer than 400 m esh, as compiled from Table 6 of the previous P ro g re ss Report! 1), The sam ples with the g re a te r component of fines w ere found to contain the g re a te r m o istu re content. No absolute in terp retatio n should be given this relationship. The figures a re a ll very close and their sim ilarity is of g reater im portance than the correlation, However, there is a theoretical basis for the variance, and the data are presented for whatever they may be worth in the light of future studies. The correlation seem s m ore than coincidental. M oisture content shows no other correlation in whole powders. Inasmuch as the lubricity-board s tu d ie s ^ showed that the lubricity variations depended upon the coaraer fractio n s, the sm all difference in the fine component as r e lated to m oisture content should have no expression in lubricity. BATTELLE MEMORIAL INSTITUTE Protected Document-Subjectto Protective order JNJAZBSJMM000B2S 20 TABLE 15. THE RELATIONSHIP OF MOISTURE CONTENT TO PER CENT OF MINUS 400-MESH PARTICLES IN WHOLE SAMPLES OF TALC COLLECTED AT CRANFORD P er Cent F i n e s t (-400 Mesh, Tyler) 88.28 88.16 87.26 86.61 86.09 85.29 83.91 83.40 83.04 82.93 82.57 82.28 P er Cent M oisture 0.06 0.07 0.06 0.06 0.05 (h 05 0.05 0.05 0.05 0.03 0.03 0.04 Date Sampled 8-28-56 9-27-56 9-6-56 11-6-56 9-19-56 8-20-56 10-18-56 12-22-56 10-4-56 9-12-56 11-30-56 11-15-56 (a) Repeated front previout report^). Johnson and Johnson's Raw M a tsria ls Specifications ih e s t states 0. 15 p e r cent m o istu re content to be the tolerable upper lim it. The Crarfford sam ples, a s w ell a s (be size fractions, contain considerably less m oisture. This indicates that any beneflciation which would change the size distribution, hence the m oisture content, would not produce a product of unsatisfactory m oisture content. Inasmuch as a pasty consistency in talcum powder would be undesirable, samples which by exposure o r otherw ise have taken on excess m oisture m ust be resto re d by p ro p e r drying. One problem arisin g from flotation experim ents was the .tendency for the products to agglom erate after drying. It is possible that this m oisture can be removed by spray drying. The problem of proper drying is to be considered further in the beneficiation phase of die program. Absorptive Power A physical property closely related to m oisture content and particle size is the absorptive power of talc. The hygroscopic property is highly im portant, inasmuch as it is a factor in deodorising, coloring, in the carrying of perfum e o r other agents, and in the retention of m o istu re. Because th is subject is only p artly understood a t this tim e, it w ill not be rep o rted on h e re . The p roperty is not im m ediately p ertinent to the other m echanical and physical relationships in this rep o rt except through m oisture content, BATTELLE MEMORIAL IN. S T I T U T E Protested Docum ent-Subject to Protective Order JNJAZS6JW0000927 21 Alkalinity The 15 sam ples of Italian tale collected a t C ranford w ere m easured for pH on a Beckman pH m eter standardised at neutrality and checked with Beckman buffer solutions of pH 7 and pH 10. The figures a re accurate to about 0. 1. The sam ples w ere p rep ared by mixing 5 g ram s of talc with 10 cc of d istilled w ater (pH 6. 9). The solutions w ere agitated and perm itted to stand for 2 hours p rio r to th e ir m easurem ent. The pH of the C ranford sam ples ranges from 9. 0 to-9. 3 (Table 16). TABLE 16, pH OF CRANFORD SAMPLES Date of Sample dH 8-10-56 9. 1 8.20.56 9.0 8-28-56 9.3 9-6-56 9.1 9-12-56 9.1 9-19-56 9.2 9-27-56 9.2 10-4-56 9.2 10-12-56 9.2 10-18-56 9.0 10-29-56 9.1 11-6-56 9.3 11-15-56 9.0 11-30-56 9.1 12-22-56 9.2 To see if th ere was any relationship of pH to other physical p ro p e rtie s, a Cranford sam ple with a pH of 9. 2 was sized and the fractions w ere m easured (Table 17). The sine fractions each m easured 9. 2, which showed that within the precision of the in stru m ent th ere was no difference due to p a rtic le size o r variation in the concentration of. carbonates. Studies in progress will determ ine the practicality of removing the dolo m ite to the degree that the pH w ill'be lowered. Effective lowering of the pH would lessen Johnson and Johnson's expense of the acid additive. BATYELLE MEMORIAL INSTITUTE Protected Docum ent-Subjectto Protective Order JNJA255JW000092B 22 TABLE 17. pH 0 7 SIZE FRACTIONS 0 7 ITALIAN TALC Tyler Mesh Size PH Unseparated 9.2 +200 9.2 -200+250 9.2 -250+270 9.2 -270+325 9.2 -325+400 9.2 -400 9.2 Acid Solubility A cid-solubility m easurem ents w ere made as a p a rt of the study of the carbonate component of Italian talc. It has been demonstrated that carbonate com prises the m ajor amount of the contamination and that its rem oval decreases abrasiveness and im proves lubricity. The p e r cent solubility was firs t determ ined gravim etric ally by the method out lined in Johnson and Johnson's Raw M aterials Specifications sheet. The figures ob tained w ere considerably lower than the 6 per cent solubility lim it perm itted by the specifications; however, they w ere greater than the figures anticipated from the small amount of carbonate m inerals observed petrographically. Solubility analyses d e te r mined gravim etrically ranged from 2.10 to 2.81 per cent, showed no relation to any of the physical p roperty m easu rem en ts. It was assum ed that th e re Was e ith e r a g re a te r amount of soluble m atter in the impalpable fine fraction, or that th ere was a constant large sample loss during handling. To resolve the problem the carbonate component was determ ined petrographically to be p rim a rily dolom ite, wad a volum etric method of analysis was devised to analyze closely for sm all concentrations of dolomite in talc (Appendix B).- The figures derived from these methods and computations are presented in this report as "equivalent dolo m ite". It is the m easure of the total p er cent of dolomite in the sam ple, not its inci dence , which is a function of grain size. The equivalent dolomite analysis is recom mended as a substitute for the previously used gravim etric analysis. The method is adjustable for larg er concentrations, and other computations may be substituted when carbonates other than dolomite a re present. Equivalent dolomite is correlative with petrographically observed contamination and with re la te d p hysical p ro p e rtie s both in size fractio n s .and in whole powder. A grab sample of Italian talc from the large bulk sample obtained from C ranford, containing slightly higher than average contamination, was analyzed for equivalent dolomite. The analysis showed 1. 87 p e r cent. To check die analysed percentage against the incidence, a s e rie s of g rain counts was m ade on separate im m e rsio n s, running 1, 8 , 1 .8 , 2. 0, 1. 8, 1. 9 , and 1. 9 p e r cent. The average 1, 8+ 1 essen tially the sam e as five 1. 87 p e r cent b a t t e l l. z memorial institute Protected Document-Subjectto Protective Order JNJAZS8 00000092# 23 determ ined volume trically. In other eases a concentration of dolomite in the coarse sizes cuts down incidence, as a concentration of dolomite in Ac fines in creases in ci dence. In the consideration of contaminants in regard to flotation, o r of the m easure m ent of lubricity o r abrasiveness, the actual incidence of the contaminants is the im portant consideration. Within the range of Italian No. 1 ta lc , how ever, the difference is usually small. Table 18 shows a com parison of the g rav im etric and equivalent dolom ite an aly ses, the incidence of contam inants, and lubricity, as listed against increasing abrasiveness. Table 19 shows contamination and equivalent dolomite com pared with decreasing lu b ri city. These show the prim ary relationship between abrasion and contam ination, and the secondary relationship of abrasiveness to lubricity in whole powders. This was also dem onstrated by Table 9 of th is rep o rt. Table 20 com pares the equivalent dolom ite, contamination, abrasiveness, and lubricity of sized fractions of Italian talc, dem onstra ting teat the fines contain the m ore abrasive participe. Inasmuch as the carbonate & tee Italian talc constitutes a ra re component in all size fractio n s, its rem oval by sizing is not p ractical. Any p ractical baneficiation proc e ss would be concerned with effectively removing the-carbonate from the whole powder, thus im proving the slip while elim inating tea m ajor abrasive. The effects of flotation on lu bricity, abrasiveness, and contamination a re presented in a report(8) on the benefielation of Italian No. 2 talc. REFLECTANCE AND WHITENESS Discussion The terminology of properties involving the behavior of light is very complex and for tea purposes of this rep o rt tee discussion w ill be lim ited to reflectance, w hiteness, and gloss. Reflectance is tes m easurem ent of the retu rn of light off of a surface in ratio to tee intensity of tee incident light. This may be m easured in term s of brightness, ap art from color. Whiteness may be m easured in either term s of reflectance over the whole spectrum as "lightness", o r in tee sense of tee absence of specific colors. Gloss is tee m easure of shininese of surface or epecular reflection, as distinct from total reflection. G loss, closely related to reflectance and w hiteness, w ill be discussed in a future rep o rt when ample sam ples a re prepared to enable assessm en t of the factors which con tro l the property. Gloss is a separate m easurem ent from those here reported. Although one may visualize the differences between w hiteness, lightness, brig h t n e ss, and gloss, one cannot subjectively differentiate one from another with any p reci sion or determ ine tee contribution of a specific property to o v er-all effect. The im portant consideration is tee total subjective effect, which is quickly noticeable. How e v e r, in figuring m eans of improving the over-all effect we m ust relate the contribution of p a rtic le s iz e , shape, and specific contam ination to bote the o v e r-a ll effect and to specific properties. F or example, fibroue talc is w hite, but less reflective than piety talc. Rutila is highly reflective-, but not white. . The beneficiation studies designed to ' battelle . memorial institute Protect! Docum ent-Subjtette Protective Order JNJAZMJM0M0830 Protected Doeument-Subject to ProtMthrc Order TABLE 18. COMPARISON O F THE GRAVIMETRIC AND VOLUMETRIC ANALYSES FO R DOLOMITE AND THE RELATIONSHIP OF EQUIVALENT DOLOMITE TO THE INCIDENCE OF CONTAMINANTS AND LUBRICITY, AS LISTED AGAINST INCREASING ABRASIVENESS Date of Cranford Sample 9-12-56 8-10-56 9-19-56(c) 9-6-56 10-18-56 9-27-56 10-4-56 8-20-56 8-28-56 11^56 11-15-56 10-29-56 11-30-56 10-12-56 10-22-56 A brasiveness, 10" 3 So. / sec 1. 62 1. 70 1.84 1. 87 1. 88 1.90 1.90 1. 91 1. 97 2. 15 2.30 2.32 2.32 2. 59 2.69 Incidence of Contaminants (*), per cent < L 1 <1 < 1 1 l 1-2 2 2 1 2 1-2 2-3 2-3 2 Equivalent Dolomite (V olum etric), per cent 1.5 1.5 1.7 1.6 1.6 1.6 1.6 l. 7 1.6 L6 1.6 1. 6 1. 7 1.7 1.7 Acid Solubility (Gravim etric), per cent 2. 14 2.47 2. 61 2.64 2.44 2.39 2. 10 2. 71 2.51 2.57 2 .2 7 2. 78 2.81 2. 58 2.30 L u b ric ity -B o a rd M easurem ent(b), sec 1. 030 1. 021 1. 028 1.083 1.025 1.017 0.982 0. 971 1..007 1. 053 0. 936 1.006 0. 952 0.968 0.965 H (i) Dwnmlwl pcnegrapfalcaUy. m (b) N relatfonsfclp d n xan tied , (c) ftemgcaphfcaUy found w'conHtte-rar* bes co n e dotonite. JNJAZMJMOOOM31 Protected Document-Subject to Protective Order TABLE 19. EQUIVALENT DOLOMITE, ABRASIVENESS, AND P E R CENT CONTAMINATION LISTED AGAINST DECREASING LUBRICITY h Date o f * C ra n fo r d " Sample r h 9"6*56 11-6-56 z 9-12-56 tv 9-19-56) S 10--18--56 O 8-10-56 9-27-56 ~ 8-28-56 * 10-29-66 10-4-56 A 8--20--56 z 10-12-56 12-22-56 -* 11-30-56 ~ 11-15-56 L ubricity-B oard M easurem ent, sec 1.083 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 Incidence of Contam inants(a), per cent <1 1 <1 <1 1 1 1 2 1-2 1-2 2 2-3 2 2-3 2 E quivalent D olom ite (Vd ia m e tr ic ), per cent 1.6 1.6 1.5 1.7 1.6 1.5 1.6 1.6 1.6 1.6 1 .7 1.7 1.7 1. 7 1.6 A brasive nessfc), 10- 3 in . ys e c 1.8*? 2. IS 1.62 1.84 1.88 1.70 M U> 1.90 1.97 2.32 1.90 1.91 2.59 2.69 2.32 2.30 H (e) Determined petxogltpiiicxUy. n (b) New, or four correlative reUtlondilp. (c) PeBogapMcagy fanai o cootun rue bat coarse dolomite. JNJAZ55_000000932 Document-Subject to Protective Order IO S<L' m > H -i TA B LE 20; COMPARISON O F CONTAMINATION, EQ U IV A LE N T DOLOM ITE, ABRA SIV ENESS, m AND LUBRICITY IN SIZE FRACTIONS O F ITALIAN TALC r Tm" I n c id e n c e o f C o n t a m in a n ts ^ ) , E q u iv a le n t D o lo m ite per cent (V olum etric), A b rasiven ess, i>ub r i c it y - B o a r d Tyler' M esh S ize s m U n se p a r a te d O 30 +200 -200+250 > -250+270 r -270+125 T o ta l 2 <1 1 1-2 2 D olom ite <2 <1 1 1-2 2 T r ex n o lite Trace 0-trace 0-trace Trace Trace per cent . . 1.9 0. 6 1. 1 2. 0 2. 0 10"^ in. / se c 2. 14 1. 30 1. 59 1. 72 2. 00 M easurem ent, sec 0. 990 0. 889 MO' 0. 951 0. 980 1. 030 -325+400 2 2 T race-l 2. 1 2. 33 1. 043 z -400 (A >2 >2 < 1 2. L 2 .4 8 1.099 H (a) Determ ined pettograpbically. H c rn JN JAZ55 ooo 27 rem ove specific partiel sise s, shapes, or contam inants, in o rd sr to improve the appearance of the talc , w ill be beet controlled when the reflectance and color properties can be assigned to particular components of the powder. As in the lubricity and abra siveness studies, when the causes of variations are determ ined, it becomes possible to visualize the means of improving the subjective property. The reflectance properties of talc begin a new category of m easurem ents. The reflectance properties are distinct from other physical m easurem ents insofar as direct relationships are concerned, except when particle size, surface area, and purity are concerned, as the following experim ents dem onstrate. It is apparent at this stage of the.investigation that some degree of over-all appearance can be controlled by die selective rem oval of particular particles. The M easurement of Reflectance and Whiteness The Italian talc is nearly pure white and highly reflective. The work under way on reflectance and whiteness is designed to devise a m eans of improving these properties, particularly in lower grade talc, as the result of interpreting their variations in r e sponse to die variations of other physical properties. The program includes determining the effect on whiteness and reflectance of the rem oval of specific sizes, shapes, and contaminants by beneficiation. To date the. m easurem ents include only those m ade on a Photovolt P h o to electric Reflection Meter* and on a Gardner Color Meter**. The Photovolt instrum ent m eas ures diffuse reflectance in term s of "whiteness" or luminous apparent reflectance (LAR). Whiteness in this sense is a m atter of lightness without regard to color, A green tristim ulus filter is used in the m easurem ent, a standard procedure which perm its interlaborstory comparisons. The instrum ent is calibrated against standard enamel and porcelain plates. The LAR of the Cranford sam ples is presented in Table 21, showing a range in m easurem ent of 95.0 to 97. 5, with no discernible relationship to other prop e rtie s of tiie whole powder. To determ ine the relationship between LAR and particle size, m easurem ents w ere made on size fractions, which dem onstrated g reater reflectance in the fines (Table 22}. This indicates that p a rtic le size and su rfa c e a re a a re im portant fac to rs. To test if particle shape is also a factor, m easurem ents w srs m ads on ths products of cyclone classification. These m easurem ents showed that the. underflow (platy talc) has a g reater reflectance than the overflow (fine aeicular talc). A third teat made on flota tion products dsm onstrated that purity of sample is also a facto r, ths float product producing a higher reading than ths starting sample. The data related to shape and purity will be included in a report on the beneficiation of talc. The Gardner Color M eter, among other applications, m easures properties des ignated as Rd and +b. Ths Rd m easurem ent is one of reflectivity in the sense of bright n ess, apart from color. Ths higher the Rd value obtained, ths g reater the brightness. The +b m easurem ent is one of color based on yellow ness, but corresponding to whiteness in n e a r white m a te ria ls. Ths low er ths +b value the g re e te r is ths w hiteness. `Model 610. Aouvolc Corporation, New York, MowYork. " Gardner inouffism Company. Betheada. Maryland. ThU (i Umllar to die uwntmsnt und by Jobaion and Jotuaon's Research Laboratory. 8ATTILL MEMORIAL INSTITUTE Protected Docum ent-Subject to PrortaeBveOrder JNJAZE6JD00Q0MM 28 M easurem ents made on the C ranford sample's showed a range qf 91. 30 to 93. 25 for Rd and 1, 55 to 1. 95 for +b, with no c o rrelatio n as yet established with other physical p ro p ertie s (Table 21), To test if p article size h as any effect on Rd and + b , m easurem ents w ere made on a s e rie s of Bize fra c tio n s, showing that brightness in creased in the fin er fractions and that w hiteness in cre ase d with fineness except for the m inus 400-m esh fraction (Table 22). In order to in te rp re t the aberrant figure the minus 400-mesh fraction will have to be subdivided and fu rth e r +b values obtained. It is expected that the concentration of ex trem ely fine acicular particles in the minus 400-mesh fraction accounts for the decrease in the +b m easurem ent. It a p p e ars, since 1. 60 is the value obtained on the whole pow d e r , that w hiteness is lower in the ex trem e.p article s iz e s , both co arse and*fine. To te s t the effect of purity of sam ple on Rd and +b, m easurem ents w ere made on benefieiated products, showing that the rem oval of contamination m easurably im proves Rd and 4b. M easurem ents to be made on cyclone products w ill dem onstrate the effect of particle shape on these properties. These studies will be presented in a forthcoming rep o rt on the beneficiation.of .talc. F urther work is recommended in the m atter of improving the sheen of talc. F u r th e r investigation is required in the tracing of the specific p ro p ertie s of reflectance to specific p articles p rio r to visualizing beneficiation for the im provem ent of sheen. It is hoped to be able to adapt a G lossm eter for use on powdered talc in. o rd e r to be able to correlate properties and plan beneficiation for the improvement of specular reflectance. When sheen can conclusively be traced to specific physical p ro p e rtie s of the pow der, * then beneficiation for its improvement can be visualized. THE DUST COMPONENT For the purpose of this rep o rt dust may be defined as that fraction of the talcum which rem ains a ir borne when the powder is shaken from its container. The dust may be collected for examination by passing a m oistened glass slide through the dust cloud which rem ains suspended in the air when talc is shaken from a container, or by sim i larly sampling the suspended m aterial after an open container is struck on the bottom onto a table o r sim ilar surface. $ueh aetion produces two classes of m a tte r, a cloud com prising the bulk of the talc which quickly se ttle s , and a fine portion which does not. M aterial so collected has been analyzed p etrographically and has been found to be com posed prim arily of platy talc, essentially free of contaminants or acicular particles. This talc rep resen ts the finer sizes of platelets - the maximum diam eter being about 15 (i in the la r g e r p a rtic le s . This roughly corresponds to the th eo re tic al <5-jLt sphere fraction^2) not including any amount of nonplaty g rain s o r c o a rs e r p late le ts; The nature of the dust component has been established and it appears likely that it is amenable to beneficiation. Work is at presen t under way devising a means of com paratively m easuring the dust component of talc sa m p le s, and to devise a m eans fo r its rem oval should it be practically separable from the whole powder. BATTELLE MEMORIAL INSTITUTE Protected Document-Subject to Protective order JNJAZ55_000000935 29 TABLE 21. Rd, +b, AND LAR MEASUREMENTS ON THE. CRANFORD SAMPLES Sample Date Rd +b LAR 12-22-56 9-12-66 8-10-56 10-18-56 11-15-56 9-6-56 8-28-56 9-19-56 9-27-56 8-20-56 11-30-56 11-6-56 10-29-56 10-12-56 10-4-56 93.25 . 1.75 93.15 1.80 93. 00 1.90 92.55 1.75 92.45 1.75 92.35 , 1.75 92.20 1.65 92.15 1.55 92.10 1.60 92.05 1.90 91.80 1.75 91.75 1,75 91.55 1.55 91.35 1.60 91.30 1.95 97.5 . 97.0 97.0 97.5 97.0 95.0 96.0 96.0 97.0 95.5 96.0 96.0 97.5 96.0 96.0 TABLE 22. Rd, +b, AND LAR AS RELATED TO THE PARTICLE SIZE OF ITALIAN TALC Tyler Mesh Size Unseparated +200 -200+250 -250+270 -270+325 -325+400 -400 Rd +b 91.40 1.60 85.60 . 1.90 89.15 1,45 90. 36 1.35 90.50 1.30 91.50 1.20 92.55 1.50 LAR 96.0 91.0 92.0 92.5 93.0 96.0 96.0 BAT TELLE MEMORIAL INSTITUTE Protected Docum ent-Subject to Protective Order JNJAZSCjDOOOODSSS 30 APPRAISAL OF PHYSICALtPROPERTY MEASUREMENTS IN THE e v a l u a t io n o f o r e 's a n d b e n e f i c i a t i o n p r o d u c t s The foregoing studies, and those previously reportedU ), have established the relationships between many of the physical properties of talc and subjective evaluation. Many of the devices employed were helpful in establishing the interrelationships of phys ical p ro p erties, have served their purpose, and their use is not requisite to evaluate the acceptability of talc, inasmuch as the' interrelationship of p ro p erties perm its such an evaluation to be made on the b asis of a minimum of m easurem ents. The su b jective te sts do not m ea su re sp e c ific p ro p ertie s and thus a r e only o f co m p arative value in deciding what is the sp ecific problem in a nonacceptable ta lc, or how it m ay be m ade acceptable by b en eficiation . Such t e s t s , h ow ever, m ust rem ain the final a n a ly sis o f a ccep ta b ility of b en eficia tio n p rod ucts or in the se le c tio n o f natural' highgrade talcs. The subjective tests are both.a m atter of touch and visual comparison. Tested by touch, individual consideration may be given to slip and abrasiveness. Quickly noted in nonacceptable talcs or improper grinds of otherwise acceptable talcs are dry floury feelin g s, p a stin e ss, the rolling of the powder', poor sp read which leaves portions unlu b ric a te d , and coarse o r sharp grit. Visually it may be quickly noted if the powder is colored or off-white, without sheen, spreads unevenly, contains coarse brilliant p arti c le s, or contains a high component of extrem ely fine dust. . t i To m easure im provem ent in ta lc , to m aintain quality control, o r to visualize p ro p e r beneficiation for the im provem ent of a t a l c ,'i t is n e c essa ry to-ntea-gurc specific physical p ro p erties of the powder as a whole, to know the size and shape of the talc p a rtic le s, and the nature of the contaminants. Following the subjective ap p raisal, of forem ost importance is petrographic exam ination. Such a study establishes the platy or nonplaty nature of a talc, identifies the contam inants, and should establish the general size distribution, incidence, degree of subdivision, habit of aggregation, and crystallographic v arieties, of the talc, carbon a te s, amphiboles, and accessory m ineral components. In o rd e r to beneiiciate for the. im provem ent of slip o r the elim ination of g r it, it is n e c e ssa ry to know the sire distribution,not'ouly of the crystallographic types of talc p rese n t, but also of the different im purities. Size-distribution procedures yield prod ucts which m ay be studied petrographically. These include screening', in the coarser fractio n s, and sedimentation in the fines. The m easurem ents assigned sedimentation products in usual procedures should be checked petrographically inasm uch as talc platelets behave in the m anner of theoretical spheres of much sm aller dimensions. A p ra c tic a l method of com paring pow ders, ao lpng as the th eo re tic al m easurem ents do not becom e m istaken for actual d iam etersj is the Andreason sedim entation technique, p re viously reported^2). W hen'this m ethod is employed, with .supporting petrography it should be a satisfactory device for evaluating'beneficiation products. Without proper size and m ineral knowledge of a sample of talc , beneficiation p ro c e d u re s cannot be developed.' C ontrol'over the physical p ro p e rtie s of a. talc of known and fairly constant composition could be kept by the use of refinem ents of the experi m en tal lu b ricity and abrasio n -m easu rin g devices. However, a knowledge of the m in e ra l ogy and size distrib u tio n is recom m ended for. any talc. BATTELLE MEMORIAL INSTITUTE Protected Document-Subject to Protective Order JNJAZ56_000000937 31 The m easurem ent of su rface a re a , specific su rfa c e , p o ro sity , and averag e diamm e ter will be considered further in regard to compactibility and ullage, and the absorptive power of talc; how ever, these a re not n ecessary to consider as p rereq u isite to beneficiation studies for the improvement of the physical pro p erties of talc. The lubricity board and abrasion machine w ere built to m easure sm all differences in heretofore purely sub jective p ro p erties and to rela te them to established physical m easurem ents. With proper m ineralogical and size-distribution knowledge, these properties will be reflected in the other physical measurements. The following presents the m easurem ents which should be attained in beneficiation products in o rd er to produce m ate ria l equivalent in quality to Italian No. 1 talc. Im provement of these properties w ill, of course, produce superior powder, when not im proved at the expense of other physical properties. Beneficiation studies on Italian No. 2 talc have produced powder considerably superior to grade No. 1 Italian talc in slip, purity, and the absence of grit. The following are the recom m ended requirem ents for beneficiation products to be the equivalent of Italian No. 1 talc. The item s considered im portant at this stage of the investigation are m arked with an asterisk. M ineralogy* P laty ta lc , 90 p e r cent o r m ore Nonplaty ta lc , le ss than 10 p er cent C arbonates, less than 2 to 3 per cent Amphiboles, less than 1 per cent A ccessory m in e rals,'tra ce only Opaques, none. Size Distribution* (1) Whole powder; G re a te r than 130 G re a te r than 200 G re a te r than 325 G re a te r than 400 ssh, none ssh, less than 1 per cent ssh, le s s than 10 p e r cent The powder should have a size-distribution curve over its general range sim ilar to that shown by Andreason sedim entation m easure m ent^) 0f theoretical p articles. Many of the particles finer than the theoretical 5-jj spheres are undesirable, representing fine acicular grains and dust. F in es, how ever, should not be removed to the extent that the bulk density is raised beyond p resent specifications. (2) Contam inants: G re a te r than 250 m esh , le s s than 1 p e r cent -250 to +400 m esh, not m ore than 2 per cent F in e r Qian 400 m esh , le s s than 3 p e r cent. Note: There is reason to believe that the grind of Italian No. 1 talc is finer than optimum for the production of a superior beneficiated talc. P ossibly talc 100 p er cent m inus 100 m esh would be fine enough. The p rin cip al reason for a minus 200-m esh grind for the currently used product may be to reduce the g rit to a size w here the p latelets m ask it. With beneficiated talc th is would not be n ecessary and there would be less fines to discard. BATTELLE MEMORI AL INSTITUTE Protected Docum ent-Subject to Protective Order JNJAZ65JX>000SS38 32 Lubricity Measurement G re a te r than 0. 93 second, p referably g re a te r than 1 second. Porosity A pproxim ately 0. 45 to 0. 50. Average P article Diameter A pproxim ately 2 .4 to 3. 3 fi. This m easurem ent is made on the F ish er Subsieve Sizer, the.figures are of theoretical particles but are not to be compared with those from the Andreason m easurem ents. Bulk Density l 22 to 24 lb /cu .ft. Specific Surface, Theoretical G re a te r than 6600 em ^/g,' preferable m easurem ents lie in the g000-cm ^/g range. Abrasion* Machine M easurement Talc p e lle ts - le s s than 2.7 x 10"3 in. / se c , p refe ra b ly le s s than 2 x 10"3 in. / sec. Carbonate p e lle ts - le ss than 1 x 10~3 in. / sec. M oisture Content L e ss than 0. 06 p e r cent, p referab ly 0. 05 p e r cent o r less. pH L e ss than 9. 4 , p referab ly c lo se r to 7 in o rd e r to low er tile expense of the acid additive. Acid Solubility G ravim etric, less than 3 per cent V olum etric, less than 2 per cent. LAB. 95. 0 o r g re a te r. Ad* 91.0 or greater. B A T T E L L- E MEMORIAL. INSTITUTE Protected Document-Subject to Protective Order JNJAZSSJWOOOOSM 33 L ess than 2.0. (An additional color m easurem ent, -a, should be taken when talcs with a yellow-green tint are studied.) The above m easurem ents concern purity, slip, and g rit, and the m easurem ent of acceptability of beneficiation products. Yet to be reported on are preferred m easure m ents on the G lossm eter, p referred lim its of the dust component, absorptiveness, and compactibility. Although specific problem s may a rise when other than Italian talc is considered, the above m easurem ents should generally suffice for m o st raw talcs in the m easurem ent of improvement by beneficiation o r of acceptability in regard to Johnson and Johnson's present requirem ents. FUTURE WORK F u tu re w ork related to`the physical p ro p er tie s of talc includes studies of the ab sorptive power to talc, m easurem ents of gloss as distinct from w hiteness and reflect ance, m easurem ents of com pactibility, the dust-component, studies on the effects of , different methods of drying processed talc on its physical properties, and further evalu ation of the physical properties and m ineralogy of beneficiation products. Because of immediate pressure on other phases of work for Johnson and Johnson m ost of the above studies will be held in abeyance. REFERENCES (1) Sm ith, W. L . , "Studies of the P h y sical P ro p e rtie s of T a lc , T heir M easurem ent, and C om parison", B attelle re p o rt to Johnson and Johnson (October 15, 1957). (2) M acdonald, R D. , le tte r re p o rt to Johnson and Johnson on the A ndreason Sedimen tation P ro c ed u re (April 1, 1958). (3) Sm ith, W, L. , and S nider, R H. , "Investigation of the Salgada and C asa Nova Talc D eposits of B r a s il" , B attelle re p o rt to Johnson and Johnson (May 28, 1957). (4) Sm ith, W. L. , le tte r re p o rt to Johnson and Johnson on the talc deposits of M adoc, Canada (July 25, 1957). (5) Brow n, W. E. , le tte r re p o rt to Johnson and Johnson on the flotation am enability of Italian and other talc s (January 24, 1958). (6) R eport in p ro c e ss describing re s u lts of c lassificatio n of talc by cycloning. BA.TTELLE MEMO RIAL INSTITUTE Prelected Document-Subject to Protective Order JIMAZSSJWM00M0 34 (7) S c ia r, C. B . , S nider, R. H. , M acdonald, R, D. , and Tangel, O. F . , "An Inves tigation of Selected Talc Deposit of the United S ta te s", B attelle re p o rt to Johnson and Johnson (F ebruary 29, 1956). (8) Brown, W. E , , Sm ith, W, L . , end M acdonald, R. D . , " T h e P h y sic a l Concentration of Talc O res - F lotation", B attelle re p o rt to Johnson and Johnson (May 23, 1958). The original notes on the laboratory work described in this report are in Battelle L aboratory R ecord Books No. 13034, pages 78 through 96; No! 14187, page's 44 through 100; No. 14431, pages 7 through 100; and No. 14677, pages 1 through-8. The work was done in the p eriod from October 21, 1957, to May 5 , 1958. W LS:djo/gpi/bah B A T T E U ! m e m o r i a l ' i n s t i t u t .e Protected Docum ent-Subject to Protective Order JNJAZSS 000000841 APPENDIX A DESCRIPTION OP ABRASION MACHINE AND TECHNIQUE OP OPERATION BATTELLC MEMORIAL INSTITUTE Protected Document-Subject te Protective Order JNJAZS(_00W00M2 A-l APPENDIX A DESCRIPTION OF ABRASION MACHINE AND TECHNIQUE OF OPERATION The experimental device described as the abrasion machine in this report (Figures 1 and 2) consists of a 1/20-hp 220-volt 60-cycle 1725-rpm th ree-p h ase Westinghouse e le c tric motor mounted v e rtica lly at operating height fitted with a ste e l lap. The steel lap has a diam eter of 5 inches and is designed so a lap cloth may be held in place by a rubber belt. A Buehler M icrocloth was selected as a standard lapdoth. The lap is housed in a steel bowl 5 inches deep and 9-1/2 inches in diam eter. A spout extends from the bottom of the bowl to carry the tested slurry into a beaker. A plastic shield is fitted over the top of the bowl to prevent spatter. A hole in the shield perm its observation of the operation and access to the sample holder and slurry feed tube. The slu rry feed tube and a cylindrical 1/2-inch-diam eter sample holder are fitted into a m etal strip which is fastened in place over the lap. The sample holder is fixed 2 inches from the center of the lap. D irectly behind the sample holder the slurry feed tube is fixed in a sim ilar position so that the clockwise rotation of the lap brings the slu rry which is to be m easured under the standard talc pellet. The talc test pellet is held onto the lap by a 16. 1-gram weight which prevents the pellet from skipping or floating on the rotating lap. The slu rry feed.tube is connected by a rubber tube with an adjustable clam p to a separatory funnel held in a ringstand. The funnel ia a SOO-ml open-top sepa rato ry funnel equipped with a stopcock, and serves as the rese rv o ir for the slu rry which is to be m easured. The tim e of operation ia kept on a Kodak electric tim er. The p ellets are m ade of m inus 400-m esh Italian talc p re sse d in a 7 . S. C arv er L aboratory P r e s s under SO, 000 psl. The p ellets sire 1/2 ineh in diam eter, and the 5. 2-gram samples used make a pellet about 7/10 inch long. In addition to the standard talc pellets used in the m easurem ent of total abrasive particles, carbonate pellets w ere used to m easure abrasion by the harder contaminants alone. The carbonate pellets were m ade by fusing three p arts by weight of sodium c a r bonate to one p a rt of sodium borate into a m elt. The fused m elt was then crushed and p ressed sim ilarly as the talc- pellets, under 15,000 psi. Because of swelling during drying the carbonate pellets m ust be m easured wet, unlike the talc pellets. Also, be cause of slight solubility, the slurry to be tested m ust be a m ixture with alcohol instead of w ater. The carbonate pellets are less satisfactory than the tale pellets, however, they served a specific experimental purpose. In operation, the slu rry , composed of 3 gram s of the talc to be m easured, in 350 m l of distilled w ater, p asses onto the rdtating lap at a rate controlled by a clam p on the feed tube. The slu rry is carried under the standard pellet where the abrasive com ponents w ear fixe pellet at a ra te approxim ating ab rasio n of the pellet by some 1800 ft/ m in of surface composed of the sample slurry. F u rs sam ples of talc w ere found to effect little abrasion, while contaminated talc was found to quickly w ear away the pellet. The amount of abrasion loss as m easured on a S tarrett m icrom eter caliper is divided by the num ber of seconds of abrasion to provide figures representing the degree of abrasion. Should sim ilar experim ents be repeated, the following a rc im portant considerations. In any se ries of te sts the operation tim e of the machine should be essentially the same. The talc slurry should be kept in suspension by agitation. A new lap cloth should be used BATTK.LLC MEMORIAL INSTITUTE Prelected Docum ent-Subject to Protective order JNJAZSSJM00S0S43 A -2 as soon as any wear is noticed. All the talc pellets used in a series of tests should be pressed at the same tim e. Talc pellets should be dried overnight before measuring to prevent any spelling effects of absorption of water. When any reruns are required on the abrasion machlrie, the slurry feed should be adjusted to reproduc form er readings be fore comparative data are sought. To m ake proper com parative m easurem ents the abrasion machine should be operating so as to make replicate tests showing a difference of not m ore' than 0.1 x 10"3 in. /se c of abrasion. i SATTELLE M I M 1 I A l ' I N S T I T U T E Protected Docum ent-Subject to Protective Order JNJAZ5S_OOOOOM44 APPENDIX B DETERMINATION OF EQUIVALENT DOLOMITE CONTENT IN ITALIAN TALC BY VOLUMETRIC ANALYSIS by W. E . Brown ' BATTEL.LE MEMORIAL INSTITUTE Protected Docum ent-Subject to Protective Order JtMAZSSJMMMWS `c ?; .......... * * X. f /itr.fyU e ` r-;i Af / / c n t /.)$ * / >J<il I A + 'l c .v ,,:" ^ / W A.':.; i . */ a -/ / f.i./. .? -i)&- ' 'v .'#' 'f ' * C'f (& i ^ I I - //o X & )'*"' >' * A X // j ' /Wie yAt-uV!*'.'/1'.* Kr"/ f YAi**- (K . r ?/';:) /y .'.i $A .v ? * <- /r /< ' ` f I t - ' /i -V : f t. v - . ' <.-7 ` ' &><<> X / jrf " ' (T"/ - 7< d M F < fl ^ X ' /* /S ~ * jr j. c*ji& 41 Y ' 4 X cX djfie, CCd /M<AA*aA4 ^ - ^ 6 ***a ** L flpU iM X . ^ /'Y -fc J ? 9 -4 - r y * C 0*Jhjvc*k>a Protected Docum ent-Subject to Protective Order JNJAZS5_OOOOOM I B -l 1 APPENDIX B DETERMINATION OF EQUIVALENT DOLOMITE CONTENT IN ITALIAN TALC BY VOLUMETRIC ANALYSIS by W. E. Brown (1) P re p a re a solution of approxim ately 0. 2N sodium hydroxide and determ ine exact norm ality. (2) P re p a re a solution of approxim ately 0. 2N hydrochloric acid and determ ine exact norm ality. (3) Weigh out for analysis a 5. 000-gram sam ple of talc and put in a 250-cc beaker. SS' {4} Add 25 m l of distilled w ater to the ta lc sam ple and s tir w ith a g lass rod to thoroughly wet the talc. (5) Add 50 cc of the HC1 solution p rep ared in Step.(2). sc (6) H eat sam ple, containing w ater and HC1, fo r 45 m inutes a t 105 C. (?) R aise tem perature to boiling for approxim ately 1 / 2 m inute to expel H2CO3. Use care so that the sample does not boil over. (8) Cool to room tem p eratu re. {9} Add 4 drops of m ethyl orange indicator to the cooled sam ple and stir. (10) T itra te the sam ple with the NaOH [fro m Step (1)} to a yellow end point. This determ ines the amount of unused acid. (11) Calculate the p e r cent dolomite. An example of the calculations is as follows: Given: N orm ality of NaOH a 0. 2055 [fro m Step (1) N orm ality of HC1 0. 2120 [fro m Step (2) Each m illilite r of HC1 contains 100 0. 2120 a 0,0077 gram of p u re HC1 1 m l of NaOH n e u tra lise s 0. 97 m l of HC1 J . j L6 dtoSs 1 gram of HC1 n e u tra lise s 1. 28 g ram s of dolom ite /./J - /, 37 47. 6 m l of NaOH was req u ired to titra te a 5 -g ram sam ple which had been digested w ith 50 m l of HC1. battelle memorial institute Protected Docum ent-Subject to Protective Order JNJA2KJI0MMB47 B -2 47.6 x 0.97 * 46.17 m l of unused HC1 50. 00 46. 17 3. 83 m l HC1 consumed by dolomite 3.83 x 0. 0077 * 0. 0295 gram HC1 consumed by dolomite 0. 0295 x 1. 26 * 0. 0372 gram dolomite dissolved by HCi T5."0z0J0J1* 100 0 .7 4 p e r cen>t dolomite. Note: In o rd er to te s t the accuracy of th is method of a n a ly sis, some relatively pure dolomite (taken from a m ineral specimen) was analyzed. The weight of the sam ple analyzed was 0. 0300 gram . The foregoing analytical m ethod showed the sam ple to contain 0. 0306 gram of dolomite. Another check te s t was made by analysing a sam ple of Italian talc for p e r cent of COj>, .and converting the COz content to the theoretical amount in dolom ite. The. C 0 2 analysis indicated that the dolom ite content was 2. 26 p e r cent. By volum etric analysis the dolomite content was calculated to be 2.18 p er cent. i B A T T C Li E MEW 0,R I A L I iN.S T t T U T E Protected Document-Subject to Protective order ONJAZSSJWOOMSU