Document 1y1wmG1e7Gx7L1XzkBbp7pVwa

FILE NAME: Johnson & Johnson (JAJ) DATE: 1958 May 23 DOC#: JAJ031 DOCUMENT DESCRIPTION: Report - The Physical Concentration of Talc Ores - Flotation - Presented to J & J I I PROGRESS REPORT oh THE PHYSICAL CONCENTRATION OF TALC ORES - FLOTATION to JOHNSON AND JOHNSON May m , 1958 by W. E, Brown, W. L, Sm ith, and R. D. Macdonald BATTELLE MEMORIAL INSTITUTE 505 King Avenue Columbus 1, Ohio H a n d le is not engaged in research for advertising, sales promotion, or publicity purposes, and this report may not be reproduced in full or in part for such purposes. itected Document-Subject to Protective Order JNJNL81JM0001343 B attelle has always had a policy that its sam e and its reports could not be used for advertising, sales promotion, or publicity purposes. P ro vision has been made for this in all of our research agreem ents and we have found that our sponsors have respected and accepted this position. This did not, of course, interfere in any way with any use the sponsor might make of the information in the report, as long as our name was not used, nor did it interfere with the use of the report within the sponsor's organization for conveying information to all of those concerned with the research project. We have found on a few occasions that use of our rep o rts in connec tion with an advertising program has occurred, probably inadvertently, because the individual using the report was Unaware of tills agreed-upon provision, even though his company had accepted our agreem ent. F urther m ore, th e re may be people who see and use our rep o rts with the sponsor' approval who a re not n ecessarily connected .with the sponsor who had agreed to bur provisions. We m ay have been re m is s in not indicating on our rep o rts the provisions that govern th eir use. Henceforth, the follow ing statem ent w ill be included with- each of o ur re s e a rc h re p o rts , a s is shown' on the title page of th is report; "Battelle is not engaged in research for advertising, sales promotion, o r publicity purposes, and this report may not be reproduced in full o r in p a rt fo r such p u rp o s e s .11 cted Document-SiOfeet to Protective Outer B attelle M emorial Institute SOS KI NG AVENUE COLUMBUS I, O H I O May 28, 1958 D r. W. H. Lycan Director of R aaearch Johnson and Johnson New Brunswick, New Jersey Dear Dr. Lycan: We a re transm itting herew ith six copies of our P ro g re s s R eport on "The P hysical C oncentration of Talc O res -- flo ta tio n " , by W. E. Brow n, W. L. Sm ith, and R. D. Macdonald. The data in this re p o rt show that it is possible to m ake from Italian No. 2 g ra d e , by flotation, a talc product that Is superior to the Italian No. 1 grade. We now have enough laboratory data to design either a pilot plant to produce larg er quantities of this m a te ria l for c ritic a l evaluation, o r a co m m ercial plant to produce a nom inal 50 tons of beneficiated talc p e r day. The data in this rep o rt indicate that it m ay be possible to produce a superior talc by flotation from any raw talc which contains an appreciable percentage of platy talc. We do not, how ever, have enough data as yet to prove th is point. Additional experi m en tal work is re q u ire d to show w hether by flotation one can m ake an acceptable prod uct from other raw m a te ria ls, such as Indian talc. A fter you have reviewed this rep o rt, we would be pleased to discuss it with you or to answ er any questions which m ay arise . Sincerely yours, OFTidpc Enc. (6) D E D I C A T E D TO THE A D V A N C E M E N T OF S C I E N C E t ed Document-Subject to Protective Order JNJNL61_000001345 TABLE OF CONTENTS Page SUMMARY ....................................................................................................... 1 I N T R O D U C T IO N ....................... 3 EXPERIMENTAL W O R K ....................................................................................................... 4 Sam ples T ested . ................................................................................................. . 4 Sam ple F ro m the O asis M in e........................................................................... 5 ' Sam ple F rom the Stone C reek M i n e ......................................................... 9 Italian No. 2 T a l e ............................................................................................ 10 D etailed Flotation E xperim ents on Italian No. 2 T a lc ........................................ 11 C O N C L U S IO N S ........................................................................................................................ 15 FUTURE W O R K ........................................................................................................................ 16 APPENDIX A DETAILS OF FLOTATION WORK A -1 APPENDIX B FROTH FLOTATION B -l BATTELLE MEMORIAL INSTITUTE lo te c ta d Document-Subject to Protective Order JNJNL61_00000134S PHYSICAL. CONCENTRATION OF TALC ORES - FLOTATION by W. E. Brow n, W. L. Sm ith, and R. D. Macdonald SUMMARY This report contains data for the physical concentration of talc ores by flotation m ethods. Flotation experiments w ere m ade on two talc sam ples from the United States and one from Italy. Most of the tests w ere made on the Italian talc because it was consid ered to be of the m ost im m ediate im portance. The principal objective of the program was to obtain a product containing a high percentage of platy talc. The re s u lts of the te s ts show that each of the th re e different samples can be treated to yield a float product that is significantly improved in its con tent of platy talc. Table 1 sum m arizes the best resu lts obtained and com pares the raw flotation feed with the beneficiated product. Table 1 shows that both the Oasis and Stone Creek sam ples were improved in grade. The original O asis sam ple contained 48 per cent pdaty ta lc and the Float 1 p ro d uct contained 63 p e r cent platy talc. The Stone C reek sam ple contained 30 per cent platy talc and the Float 1 product contained 85 per cent platy talc. Although these flo tation products show a substantial im provem ent in platy-talc content, they lack about 5 p er cent of being equivalent'to the 88 to 90 p e r cent p la ty -ta lc content of Ita lia n No. 1 grade which is currently being used by Johnson and Johnson as the raw m aterial for baby powder. Although the d e sire d grade of a t le a s t 88 to 90 p er cent platy talc was not attained on either the Oasis or Stone Creek sam ples, a substantial im provem ent was obtained as the resu lt of relatively few tests. It is expected that a suitable method can be developed, through additional w ork, to yield a satisfactory product from the Oasis and Stone Creek talcs. I Italian No. 2 talc likew ise responded favorably to flotation. Two m ethods w ere developed which yielded products th at contained 96 to 97 per cent platy talc and 2 to 3 per cent of fibrous talc. M ineralogically, these products a re superior to the Italian No. 1 talc which is being used by Johnson and Johnson for baby powder. The flotation experim ents established that the nonplaty talc can be d e p re sse d by using the p ro p er am ounts of either Dextrin*!1o r hydrochloric acid, When D extrin was used the froth of the float products was very voluminous and p e rsiste n t which probably would create handling and filtering problem s in full scale operations. When hydro chloric acid was used the character of the froth appeared norm al and rapid filtration was obtained. * Dextrin it made by che hydrolysis of starch and is manufactured by Clinton Foods Incorporated, under the name of Dextrin 603. BATTELLE ME MORI AL INSTITUTE elected Document-Subject to Protective Order JNJNL61_00000134? n i 1 a ao 3 ft S I o O a > -t m r r IQ Sample Product TABLE 1. SUMMARY OF FLOTATION RESULTS Weight pet Cent of Flotation Feed Piety Talc Mineral Count, per cent NonpUty T alc Carbonates Oasis . m Oasis O Stone Creek 9 Stone Creek Feed Float 1 Feed Float 1 100.0 48 43 5 34.6 83 16 <1 100.0 So v 6T 1 29.9 85 12 1 > Italian No. 2 Feed 100.0 90 - 6' 3 r Italian No. 2 Float 1 83.9 98 3 <i Italian No. 2 Float 1, 2 82.7 97 2 <1 and icaveager 2 Italian No. 1 Not seated 100.0 88-90 8-10 <2 in H Note* Italian No. 1 Is included foe comparison. -I C H IQ Ttemolite 4 1 2 2 1 <1 1 Trace Effective Reagent -- Dextrin -- None CSJ -- Dextrin Hydrochloric a d d 3 On objection to tbe use Of* Dextrin, other than the unsatisfactory frothing proper tie s, would be the possibility of fungus growth on the talc particles if it were not washed out completely or destroyed by heat Airing the drying operations. INTRODUCTION Johnson snd'Johnson is-interested in a broad program .w hich includes investigating I the im p o rtan t'talc deposits in th e w orld, the m ea su rem e n t of the physical p ro p e rtie s of. ta lc , and the ph y sical benefiei&tion of talc. The p u rp o se of th ese investigations is to. ' insure Johnson and Johnson of the least expensive and m ost reliable raw -m aterial source I and iso to develop methods for further improving the p ro p erties of the ta le used in baby powder. At p resen t, Johnson and Johnson is obtaining raw m a te ria l for baby-powder talcum _ from Italian- deposits. This talc is regarded as very good quality. Same additional im - I provement in quality is desirable, however, and m ay be possible by physical beneficia- * tion m ethods. None of die known dom estic talc deposits can com pare in quality with the m Italian ta lc , and p a rt of this program is devoted to processing talcs from the m ore suit- I able dom estic sources in o rd er to obtain a product that is com parable in quality with the Italian, talcs. This P ro g re ss R eport discusses inform ation obtained on methods of improving the properties of talc. This work is identified on the o v er-all program being conducted at B attelle as Phase 3 -- Physical Concentration of Talc Ores. The specific objectives of Phase 3 are: (1) To obtain a product which consists e sse n tia lly of ta lc p latelets B (2) To re je c t tale p article which a re of a s ia e and shape that c re a te unpleasant dusting while diepensing talc from a container I {3) To obtain a talc product with an obvious -sheen in o rd er to convey B to the consumer tbe imm ediate im pression that the talc is of the highest quality.* in addition to achieving the foregoing objectives, it is desirable that the finished _ product w ill m eet the following specifications. * M oisture: Not m dre than 0.15 per cent. B Solubility inHydrochloric Acid: Not m ore than 6 p er cent. Fineness! B Not le s s than 99* 7 p e r cent through a100-m esh sieve. Not less than 98. 5 p e r cent through a 200-meeh sieve. M icroscopic Structure: B Shall be platelets, and show noacicular orexcessive granular crystals. " BATTELLE l> te c te d Document-Subject to Protective order MEMORIAL I.-NSTITUTE JNJNL61_080001349 4 Sulk Density; Not le ss than 22 nor m ore than 27 pounds p er cubic foot, when tested by the Scott Volumeter. In fu rth er keeping with the standards of production, it is d e sira b le that the f in is h e d talc product have essentially the same w hiteness as that curren tly being m ark eted by Johnson and Johnson. Another objective is to reduce the alkalinity of the raw m aterial so that the pH value of a m oistened sam ple will approxim ate n e u tra lity , or a pH of 7. P roducts obtained from physical beneficiation experim ents can be evaluated by m icroscopic examination and other physical m easurem ents. These other physical m eas urem ents and th e ir meaning a re related'.to the p ro p e rtie s of an accepted standard talcum product. A P ro g re s s R eport on "Studies Of the P hysical P ro p e rtie s of T a lc, T heir M easurem ent and C om parison", October 15, 1957, by W. L ..Sm ith, has been subm itted to Johnson and Johnson on this subject and a second and sum m arizing one is in preparation. The only m ethod of ph y sical beneficiation employed so fa r has been flotation. This is because one of the outstanding p roperties of talc, from the standpoint of physical beneficiation, is its natural floatability. This rep o rt is composed p rincipally of resu lts from froth-flotation experim ents. For this reason a short discussion of the froth-flotation pro cess is included as Appendix B in the hope that it m ay be helpful in understanding the experim ents. EXPERIMENTAL WORK Samples Tested Three samples from separate sources were used for the beneficiation experiments. Two of these a re from the United States and one from Italy. These sam ples have a wide variety of purity with respect to degree of platines and the contained im p u rities, and probably are typical of what m ay be expected in talc deposits of .potential interest. Table 2 shows the com position of these sam ples as determ ined by m icroscopic count. TABLE 2. MINERALOGICAL COMPOSITION OF SAMPLES INVESTIGATED Sample Oaclt Mine (Nevada) Stone Creek Mine (Montana) Italian No. 2 Italian No. 1 Platy T alo 48 30 90 88-90 Mineral Count, per oent Nonplaiy Talo Carbonates 43 5 " 67 1 6 (fibrous) a 8-10 (fibroui) <2 T rent olite 4 2 1 Trace. Grind Minus 65 mesh (dry) Minus 85 mesh (dry) Minus 200 mesh (at received) Minus 200 mesh (as received) B A T T E L -L E M E M O R I A L INSTIT T E Protected Document-Subject to Protective Order JNJNL61_000001 5 The m in e ra l count given in Table 2 is m ade solely on the b a s is of incidence. No emphasia-is given to the sise of the particle encountered in the incidence, so the method of evaluation m ay at firs t seem questionable. However, repeated counts made on differ ent fields of the sam e sample and different sam ples of thy sam e m ate ria l give su p riaingly consistent percentages, and the percentages of carbonate present agree with chem ical determ inations of acid solubility. Because of this consistency, the method was accepted as sufficiently accurate for m ost of the investigations. P a rtic le s in Table 2 which a re identified a s nonplaty talc m ay be composed of acicular, fibrous, granular, or eryptocrystalline aggregates of tiny platelets which resem ble granules. Nonplaty talc contained in the Italian sam ples is m ostly fibrous o r 'acicular in form. It is difficult to distinguish acicular talc from rem nants of platelets and trem olite 'in sise s s m a lle r than 10 m icrons. Table 2 includes, for com parison, the com position of the Italian No. 1 grade which is the raw m aterial currently used in Jphnson and Johnson baby powder. The m ineralogical difference between the No. 1 and No. 2 grades is alm ost insignificant. Italian No. 1 talc , how ever, coats sev eral dollars m o re per ton. The Oasis and Stone Creek Mine sam ples w ere selected to determ ine whether talc of a low platy content could be im proved sufficiently to com pare favorably with the Italian talc and, if so, what recovery m ight reasonably be expected. Data on the beneficiation of various talcs would provide inform ation that would p erm it an estim ate of the tonnage of m ate ria l necessary to supply the production requirem ents of Johnson and Johnson. Information could also bo developed for the probable cost of beneficiation. Ten exploratory experim ents w ere m ade to observe the general response of the m inerals during flotation and to learn the relative complexity of the problem . The sum m arized resu lts of these experiment# w ere contained in our letter report of January 24, 1958, to D r. W. H. Lycan. Sample F ro m the O asis Mlao The O asis Mine sam ple came from Nevada and was supplied by the S ie rra Talc and Clay Company. This m aterial was available because it had been previously investi gated by B attelle(I) for Johnson and Johnson as a potential raw talc source. The m ate rial. on hand had been ro ll-cru sh ed and then ground in a disc pu lv erizer through 65 mesh. This sa m p le , which contained about 48 p e r cent platy ta lc and 43 p e r cent g ran u lar talc, was selected for p art of the investigation specifically because of its interm ediate platy -talc content. It was believed that any significant im provem ent m ade on the ore would be m o re readily detected on low -grade m a te ria ls than on high-grade m ate ria ls. Table 3 shows the flotation resu lts obtained from five te sts made on the Oasis sample and Table 4 gives the test operating conditions. The results given in Tables 3 and 4 show that the Oasis talc in Test 1 was floated without any reag en ts and the p latin e ss of the talc, w as in c re a se d fro m 48 p e r cent to 77 per cent. This definitely establishes that platy talc is m ore readily floated than granular (1) Batteile Summary Report, February 29, WW. battelle memorial institute (acted Document-Subject to Protecflvs Ordar JNJNL61_000001381 TABU 3. SUMMARY OP FLOTATION RESULTS ON OA8IS TALC SAMPLE (MINUS 6S MESH) Ten Reduce l Float 1 Float 2 Weight Percent 32.2 21,0 Piety 71 46 Approximate Miner! Count, per cent ____N ojiy ______ Carbonate ____ TramoUte 80 1 8 60 2 3 Reagent Dud None Dowfroth 200 2 Float 1 82.4 76 24 Float 2 38.4 46 48 <1 <1 10 Nose Dowfioth 200 3 Cleaner 81.6 B0 18 1 float * 1 D w ftoth 200 Sa Float 1 34.6 83 IS <1 ' 1 Doxuln 8 Pleat 1 26.9 82 16 1 2 Dextrin F lo a ts 68.3 60 36 1 4 Flotation 100.0 48 43 8 4 toed TABU 4. TEST CONDITIONS USB) TO OBTAIN RESULTS ON OASIS TALC SAMPLE . Pulp Per Cent Solida Teat Freda Wards* Ceadltioaiiis Fieetinc PH in Peed i 1 Reagent, pound per ton of l Float 1 10 0 6 8.8 13.0 None F lo a ts 0 0 6 Dowfroth 200, 0.17 2 Float 1 10 FleatS 0 3 C lean 2 float 0 6 8.8 8.8 None 0 8 Dowfroth 200. 0.34 10 . 8 6.0 None Sa Float 1 8 6 8 8.8 13.0 Dextrin, 0.54 8 Float 1 5 8 6 8.8 13.0 Dextrin, 0.94 It 1 1; I 4 1 Id l 1 V 1 < lg |! l l1 | 1 < | t TM 1 \ 1 f B A T T E L L E M E M O A 1AL Protected Docurnan t-8 ubfect to Protective Order I NS T 1T O T E 1 ! JNJNUIJMOOOial ! 7 talc. The only requirem ent was agitation and aeration of the pulp. Additional recovery of talc was obtained by using Dowfroth 200 (a frothing and collecting reagent for talc) but the float product was essentially the same quality as the feed. Carbonates in the Float 1 product were reduced from 5 per cent to 1 per cent or less. Trem olite was m ore difficult to reject although less than 1 per cent was observed in the Float 1 product of T e st 2. T rem olite rejectio n was accom plished by reducing the p e r cent solids in the flotation feed from 13 p e r cent to 6. 8 p e r cent. T est 3 was m ade by refloating the com bined Float 1 and Float 2 products of T est 1. ThiB yielded a product which was 80 p er cent platy talc and contained 31. 6 p e r cent of the original feed weight. . Because platy talc is m ore readily floated than nonpl&ty ta lc , it was believed that the addition of a talc depressant such as Dextrin m ight have a selective depressing action on the nonplaty talc form s which had appeared in the Float 1 products. Dextrin w as used in T ests 5a and 8 , and the re s u lts show that D extrin in the amount of 0. 54 pound per ton of flotation-feed solids was effective and helped to produce a Float 1 prod uct that was about 83 p e r cent platy talc. . D extrin in th is amount appeared to be effective in causing a sm all increase in recovery. In T est 8, the Dextrin added was increased to 0. 94 pound p e r ton of flotation-feed solids. The quality of the Float 1 product was e s sentially the sam e as in T est 5a, but the weight rec o v e ry d e c re a sed to Z6. 9 p er cent com pared with 34. 6 per cent when the le s s e r amount of D extrin was used. The resu lts of the five tests on the Oasis talc show that although none of the prod ucts obtained w ere m ineralogically equivalent to the Italian ta lc , substantial im prove m ent had been obtained. The best resu lts were obtained from T est 5a which yielded a product containing 83 p e r cent platy talc. A com parison of the Oasis Float 1 product w ith the Italian sam ples is given in Table 5. TABLE S. COMPARISON OP OASIS FLOAT 1 WITH ITALIAN NO. 1 AND NO. 2 TALCS Test 5a, Float 1 Italian No. 1 Italian No. 2 weight Per Cent 34.6 100.0 100.0 Piety Tele 83 38-80 90 Fibrous Talc 2 8-10 8 Mineral Count, per cent Granular Talc Carbonates 14 <1 0 <2 0 3 Tremolite . 1 Trace 1 The quality of the Float 1 product approaches that of the Italian No. 1 ta lc , and it is not unreasonable to expect that an equivalent grade might be developed after further investigations. The products of T est 8, which gave resu lts of the sam e order as T est 5a w ere exam ined m icroscopically in considerable detail. Each flotation product was sixed on a 200-meaK sieve and the oversize and undersize evaluated. These resu lts a re shown in Table 6. The data given in Table 6 show that in the Float 1 product the plus 200-m esh talc is 61 p er cent platy talc but the m inus 200-m esh talc is 87 p e r cent platy talc. I t is im plied that better o v er-all resu lts would have been obtained by grinding the Oasis sam ple all through 200 m esh before floating. This was not trie d , and if n e c essa ry it can be done a t a later stage in the program . battelle memorial institute otected Document-Subject to Protective Order JNJNL61 000001353 r- s. j TABLE 6. RESULT5 OF MICROSCOPIC EVALUATION OF FLOTATION PRODUCTS FROM OASIS TALC, TEST 8 Flotation Feed -654200 menh -200 menh A ll-200 m sh(a) Flos 1 -654200 menh - 200 m f *h A ll-200 m*sh(*) Weight P er Cent 30 70 100 Piety Talc Minnral Count, per cent Nonplnty Talc C arb o n ates * T rem o lites . 45 45 4-5 4 49-50 40-43 4-5 3-4 48 l \ / 43 4-5 3-4 29 61 37 <1 2 71 87 10 <1 2 (26.9) 82 15 <1 2 Float 2 -654200 m esh 50 ' 24 71 1 4 -200 menh 50 70 25 1 4 A ll- 200 m esh(a ) (56.3) 60 35 1 4 * Underflow - 654200 m esh 18 20 54 18 ' 8 - 200 m enh 82 22 54 15 9 A ll- 200 meeh< (16.0) 25 51 16 8 () Some o f the plus 200-m eih psrtid e s that appear to b e 'notipUty, ate actuaby aggregates of minute platelets whloh become discrete platelets when ground fines than 260 mesh. A mote accurate mineral count Is obtained by grinding the entice product and then evaluating with the microscope, m addition to this, a minus 200-m esh product has a nanowet range of sleet than a minus 85-tneih product which Increases the accuracy of a ralctoteoplc count and finally, the minus 200-mesh product hat a U se range similar to die Italian tales discussed in detail lu e s in the report. B A T - T I L L ! . MCMORJ. AL I N S T I T U T E ' Protected Documaot~-Subjset to Protective Order JNJNLB1 000001 9 5am ple From the Stone C reek Min The Stone C reek m ine am ple cam e from Montana and w as lupplied by the South ern California M inerals Company. This m aterial was available because it also had been previously investigated by BatteUeU) for Johnson and Johnson as a potential raw talc source. The m ate ria l on hand had been prepared to m inus 65-m esh size in the sam e m anner as the Oasis sample'. This sam ple contained 30 per cent platy talc and 67 p e r cent nonplaty talc . Two flotation tests w ere m ade, and'the resu lts a re given in Table 7. Table 8 lists the operating conditions during the tests. TABLE 7. SUMMARY OF NOTATION RESULTS ON STONE CREEK TALC SAMPLES (MINUS 85 MESH) Ten Product 4 Float 1 Float 2 Weight , Pet O ne 28.9 88 18.1 80 8 Float 1 26.5 88 Flotation 100.0 80 feed Approximate Mineral Count, per cent Nowftity Carbonate 12 80 . 1 10 10 2 67 1 TremoUte 2 2 2 TABLE 8. TEST CONDITIONS USED TO OBTAIN RESULTS ON STONE CREEK SAMPLE Percent Reagent, pound! Tim e, minutes Pulp Solid, per ten of Tm I Product Wettina Ceodidoftlps H oatia______ pH____ in Feed ftotaden feed 4 Float 1 10 0 Float 2 0 0 8 9.0 13 8 None None 6 Float 1 8 5 5 8.8 Dextrin, 0.54 NadUOg. 1.08 T e st 4 shows that about 30 p e r cent of the talc is re c o v e re d in a float product con taining 85 p er cent platy talc. No reagents w ere used, which illu stra te s again that platy talc is m ore readily floated than nonplaty talc. Test 6 yielded a float product that con tained 86 p e r cent platy talc^and 10 p e r cent nonplaty ta lc . D extrin and sodium silic a te were used to.reject the nonplaty talc but the effect, from the amounts used, was not pronounced. The quality of the Float 1 products approaches th at of the Italian No. 1 tale which is 85-90 per cent platy talc. Through additional experim entation a method probably can be developed, to tre a t the Stone C reek talc , which will yield a product of quality equiva lent to Italian No. 1 talc. (1) Battalia Summary Raport, February 28, 1958. ATTILLI MEMORIAL INSTITUTE lo tB cied Document-Subject to Protective Order JNJNL61 000001355 ia Italian No. 2 Talc Three te s ts w ere m ade on Italian No. 2 talc as p a rt of the exploratory p ro g ra m , and the re s u lts a re given in Table 9. T ests 10 and 11 w ere m ade at 6. 8 and 13. 0 per cent solids, respectively, using the same reagent combination in each, to determ ine the weight recovery obtained at low and interm ediate p er cent of feed solids. The resu lts show that at 6. 8 per cent feed solids the weight rec o v e ry was 75. 3 p e r cent while at 13. 0 p e r cent solids the weight recovery was 85. 9 p e r cent. T est 12 was m ade at 13. 0 per cent so lid s, without any rea g e n ts, to com pare with T est 11. The re s u lts show that the Float 1 product was no b e tte r than the flotation feed and also only 59. 9 p er cent of the weight was floated. In T est 10 the froth of the Float 1 product was broken down e a sily , but in T est 11 the froth was v ery difficult to b rea k down and f i l t e r ., Undoubtedly this would p resen t handling difficulties in a plant. A summ ary of these results indicates that: (1) B etter re c o v e rie s a re possible when using 13. 0 p e r cent feed solids com pared with 6. 8 p e r cent feed solids. (2) D extrin is effective in reducing the amount of nonplaty (fibrous) talc in the Float 1 product. (3) Dowfroth 200 is needed to obtain good weight recovery. (4) The froth of the float products is easy to b rea k down when the per cent feed solids is low. However, the lower p er cent feed solids re su lts in a low er yield of F loat 1. Following these exploratory experim ents, a program was started to improve the froth ch aracteristics without sacrificing the platines of the Float 1 product and to m ain tain or raise the per cent of weight recovery. Forty-four flotation tests were m ade, all on Italian No. 2 talc. TABLE 9. SUMMARY OF PRELIMINARY FLOTATION RESULTS ON ITALIAN NO. 2 TALC Test Product Weigh! Per Cent _____________ Approximate Mineral Count, per cent Flaw NoneUty Crbonites T tem o llte 10 Float 1 `IS. a 96 3 <1 cl 11 Float 1 88.9 96 3 <1 <1 12 Float 1 89.9 89 8 2 1 Flotation 100.0 90 6 3 1 feed BATTEL- LE MEMORIAL Protected Document-Subiect to Protective order INSTITUTE JNJNL61_000001 Tes 10 u12 11 TABLE 10. TEST CONDITIONS USED TO OBTAIN RESULTS OP TESTS 10, 11, and 12 Am Per Cent T im s, minutes Fulp Solids Ptoduet Wetting DxxUcloalnc n e s tln PH In Feed Reagent, pounds per ton of flotation fend Float 1 6 6 10 8.1 8.8 Dextrin, 0.94 Dowfroth 200, 0.34 Float 1 S 6 10 9.0 13.0 Dextrin, 0.94 Dowfroth 280, 0.34 Float 1 10 0 10 8.9 13.0 None Detailed Flotation Experimente on Italian No. 2 Talc The m ethods considered in these teste called fo r trying various quantities of D extrin and Dowfroth 200, replacing or supplementing Dextrin with Guartec (a guar gum), using an interm ediate p er cent of feed solids, stage addition of reagents, regu lation of pulp pH during the flotation period, and dewatering and refloating the flotation underflow. The complete tabulation of these resu lts and the operational data of these tests are given in Appendix A. The m ore significant inform ation contained in these tests has been abstracted and is given in the following tables. Table 11 contains the r e s u lts obtained fro m experim ents relatin g to the effect that the quantity of frother used has on the amount of talc recovered. TABLED. ITALIAN NO. 2 TALC Q7LUSNCE OP QUANTITY OP FROTHfit ON WEIGHT RECOVERY OP TALC BY FLOTATION Float Ptoduet W e t t Recovery, Test pet cent Dowftodrf*), pounds pet ton of f#d solids 88 61.0 37' 10.4 36 18.3 38 91.0 None 0.11 0.34 0 . (a) Chemical composition is discussed in Appendix A. Character of Froth Good Fete Poor X X X X Ptaty Tale, per cent Mostly Ones 98 96 94 Each of the te s ts re p o rte d in Table 11 waa m ade a t 10 p e r cent feed solids and included D extrin(l) in the equivalent amount of 0. 47 pound p e r ton of flotation feed solids. The pH of the pulp was 8. 6. The rssu its of these tests illu strate die natural floatability of the talc and the ad ditional collecting p ro p e rtie s of the fr other. T e st 36 shows that 51.0 p e r cent of the talc ( 1) Chemical composition U discussed in Appendix A. A TTIU l MEMORIAL INSTITUTE clad Document-Subject to Protective Order JNJNL81_000001S57 12 float* without any frother. The amount of talc floated increases according to the amount of frother added. However, an increase in the amount of frother added resulted in fro th s m o re difficult to handle. When 0. 34 pound of fro th e r was added, the fro th was composed of a large.quantity of very fine bubbles that re siste d defrothing. Addition of fro th e r in in crem en ts of less than 0. 1? pound p e r ton of feed m ight lead to b e tte r fro th control, and this can be tried at a later date if suitable results are not obtained by other m ethods. T e sts 35 and 37 both yielded a float product th at w as 96 p e r cent platy talc. How e v e r, the rec o v e ry of talc was in creased .fro m 70. 4 in T est 37 up to 83. 3 p e r cent in T e st 35 by the addition of twice as m uch Dowfroth, although the higher rec o v e ry was characterised by a less suitable froth. * A aeries of experiments was m ade to determ ine the effect of per cent of solids in the flotation feed on the amount of talc recovered,in the float product. The resu lts of th ese experim ents a r e shown in Table 12. TABLE 13. ITALIAN NO. E TALC INFLUENCE OP PEED PER CENT SOLIDS ON WEIGHT RECOVERY OF TALC BY FLOTATION Twt ' 10 21-84 Float Product Weight Recovery, per cent 75.3 83.8 Feed Solids, set cent 3.3 13 Character of Froth Good Fair Poor X . X Play T alc, per cent 96 96 In each of th ese te s ts the reagents added w ere D extrin 0. 94 and Dowfroth 0. 34 pound per ton of solids. The pH of the pulp was 8.6. The data of Table 9 show that a higher weight recovery is obtained when a higher p e r cent of feed solids la employed. A t 6. 6 p e r cent s o lid s, 75. 3 p e r cent of the weight is re c o v e re d , and of 13 p e r cent s o lid s , 83.9 p e r cent of the weight is reco v ered . This is a substantial difference considering that the same degree of platiness in the float p roduct is obtained by either approach. H ow ever, the fro th produced fro m a feed of 13 p er cent solids was difficult to handle. The amount of Dextrin used has a m arked influence on the platiness of the talc floated and a slight influence on the weight of talc recovered. T ests that illustrate the m agnitude of these fa c to rs a r e given in Table 13. TABLE 13. ITALIAN NO. 2 TALC INFLUENCE OF QUANTITY OF DEXTRIN ON WHGHT RECOVERY OF TALC BY FLOTATION T fit IS 96 82-84 Flotation feed Float Product Weight Recovery, P s tc tS t 91.7 82.5 88.9 100.0 aATTCLUC- Dextrin, pound! per con of feed toltdJ 0 0.16 0.94 -- memorial Mineral Count PIMy T alc, Fibroin Talc, per cent per cent 89 B so 9 PS 3 90 6 1N S T 1r u r e Froth Good Poor Peer -- Protected Document-Subject to Protective Order JNJNL61JMO0P1 13 E ach te s t was m ade a t 13 per cent solids and 0- 34 pound of Dowfroth was added p er ton. The pH of the pulp was 8.6. Data given in Table 13 show th at Dextrin has a tendency although slight to in crease the weight of talc recovered. More significantly the data show that when no D extrin was used the talc floated wag only 89 p e r cent in the platy form which is e s sen tially the sam e purity as the flotation fe e d .' When the equivalent of 0. 94 pound of Dextrin was added the float product was 96 per cent platy talc. It is indicated that Dextrin is not a talc depressant in every sense. More specifi cally Dextrin acts as a depressant for noaplaty talc and a m ild activator for platy talc. The distinction is not sharp, but it is evident. The separation of platy talc iron nonplaty talc m ay be patentable, and the Battelle Patent Section is conducting a novelty and art search on the subject. Guartec (trade name of guar gum distributed by G eneral Mills) is also known as a talc depressant and froth m odifier. T ests w ere m ade with various quantities of Guartec to determ ine whether it would selectively depress nonplaty talc and also whether any im provem ent in the quality of the froth might be expected. The sum m arized resu lts of these te s ts a re given in Table 14. . TABLE 14. ITALIAN NO. 2 TALC INFLUENCE OF QUANTITY OF GUARTEC ON TALC WEIGHT RECOVERY, PLATINES5 AND FROTHING PROPERTIES Test 17 16 34 ' Guartec, pounds per ton of feed solids 0.47 0.94 0.94 Feed Solids P e r Unit 13 13 20 Float Product Weight R ecovery, per cent 87.6 71.0 77. 3 Platy Talc, per cent 94 94 91 Froth Fair Good, Good In each of the tests reported in Table 14, 0. 34 pound of Dowfroth was added, and the In itia l pH of the pulp was 8. 6. No D extrin w as used. G uartec, in the amounts used, did npt aid in producing a float product that was as good as that obtained with Dextrin. When D extrin w as u sed , a product containing 96 per cent platy talc was obtained, 'but the b est product obtained using G uartec was only 94 per cent platy talc. The type of froth produced with G uartec was m uch easier to handle, although this is not significant if satisfactory improvement in quality cannot be obtained. The foregoing discussion describes the m ost significant data obtained regarding the floatgbility of talc when Dextrin and Guartec were used. The best results were ob tained from T ests 21-24 when 83. 9 per cent of the talc was reco v ered in a float product th at was 96 p e r cent platy ta lc , 3 p e r cent fibrous ta lc , and le s s than 1 p e r cent each of dolomite and trem olite. The froth obtained by this method would be difficult to manage. A com parison of the physical properties of raw Italian No. 1 and No. 2 ta lc s, and the fro th flotation product fro m No. 2 ta lc , is m ade in Table 15. BATTELLE MEMORIAL INSTITUTE Document-Subject to Protective Order JNJNL61_000001S68 14 TABLE 15. COMPARISON OF PHYSICAL PROPERTIES OF RAW AND FLOATED TALC (ITALIAN NO. 1 AND NO. 2) Bulk Density, lb p e r cu ft Acid Solubility, p er cent!*) pH Alkalinity. Relative Lubricity(b) Relative Abrasion!c) Weight P er Cent of Raw Talc M ineral Count, per cent Platy Talc Fibrous Talc Dolomite T rem olite Italian No. 1 Raw 23.7 1.9 9.2 0.935-0.990 0.00214 100.0 88-90 9 <2 <1* Italian No. 2 Raw Floated 21. 5 2. 2 8. 8 0.926 0.00259 100.0 23.6 1. 2 8.7 1.017-1.051 0.00132 80-86 90 96 .5 3 3 <1 2 <1 (a) The figurei for acid solubility are at variance with information submitted unofficially in a similar table to Johnson and Johnson by R. D. Macdonald. The acid solubility as shown above is considered accurate, and a description of the method of analysis and the reason for using it will be discussed in a forthcoming report. (b) The larger the number, the more lubricious the talc. See Battelle progress Report to Johnson and Johnson 'Studies of the Physical Properties of T alc, Their Measurement and Comparison", by W. L. Smith, October IS, 1951. (c) The implication o f these numbers will be discussed in a forthcoming report. The mote abrasive material produces the highest number. Table 15 shows that the floated Italian No. 2 talc has a m o re d e sira b le m in e ral composition than the raw talc, less acid-soluble constituents (dolomite equivalent), better lubricity, and is about one-half as abrasive. Although the p o ssib ilitie s of fu rth e r im provem ent of quality, re c o v e ry , and froth properties w ere far from exhausted when using Dextrin or Gu'artec, a different approach seem ed advisable for two reasons. F ir s t, D extrin and G uartec, although not toxic, might be objectionable because they a re organic compounds that may cause rancidity or fungus .growth if not thoroughly rem oved or destroyed during the p ro cess. T h is, of cou rse, would be undesirable for baby powder. The second reason for a different ap proach is that a m ore controllable froth is desirable. In nonm etallic flotation p ro cesses, excessive frothing is not uncommon when the operation takes place in pulps having a high pH value. Most of the foregoing te sts w ere m ade at a pH of about 8. 6, and while this is not considered extrem ely high, investigation of lower pH values appeared to be w orth while. In o rd e r to lower the pH to approxim ately n e u tra l, it was decided to use an inorganic acid, such as hydrochloric, and complete the flotation before the acid was neutralized by the dolomite in the pulp and before the pH began to ris e noticeably. A s e rie s of te s ts was m ade using hydrochloric acid a s a pulp m odifier w ith some encouraging resu lts. Data obtained fTom these experim ents a re shown in Table lb. BATTELLE Protected Document-Subject to Protective Order MEMORIAL INSTITUTE <INJNL61,,000001 15 TABU U . FLOTATION RESULTS OBTAINED USING H a AS A PULP MODIFIER AND VAJUOUS AMOUNTS OF DOWFROTH AS A TALC C aU C T O R (IT A U A N NO. 2 TALC) Tt 43-46 52-65 39 43-46 53-86 41 40 60 61 Dowfroth, pound* per ton of feed lids None 0,04 0.11 0.13 0.17 0.22 0.21 0.17 None Feed Solid!, percent- 0 10 ' 10 10 10 10 10 .18 3 Float Product Weight Recovery, per cent 60.2 57.8 71.1 74.8 76.6 77.6 76.7 77.1 83.0 Piety Tele, per cent 98 98 97 97 97 96 94 96 7 Fro* Good Good Good Good Good Fair Poor Good Good In each te s t the q u iv alait of 0. 09 pound of HC1 p e r ton of ore w as added, and the pulp pH was about 7 .6 -7 . 8. The wetting tim e before reagent addition was 5 m inutes, and the conditioning tim e w ith HC1 before flotation was 2-3 m inutes. The re s u lts given in T able 16 show that a float product containing a t le a st 97 p e r cent platy talc and having acceptable frothing p roperties is readily obtained. Increasing the amount of frother increased the weight recovered, but it was noted during this series of tests that 0.11 pound of Dowfroth was about the maximum that could be added to obtain the Float 1 product without encountering frothing problem s. The float products all filtered rapidly but the underflow products filtered slowly. This sug gests that the solids in the underflow are much finer than the float products. The size distributions of the products obtained from T ests 43-46 were determ ined. These w ere d isc u sse d in a le tte r re p o rt dated A p ril 1, 1958, to Dr. W< H. Lycan. The data show that the flotation feed was 13. 5 p er cent fin e r than 4. 7 m icro n s but the flota tion underflow was 26. 7 per cent finer than 4.7 m icrons. Although the Float 1 product contained only 9- 7 p e r cent of the weight fin e r than 4 .7 m ic ro n s , it is our b e lie f, as judged from handling of the product, that flotation alone did not remove enough p articles of dust-form ing size to be acceptable. Elim ination of those sizes which create a ir borne talc particles probably w ill require a cyclone type of treatm ent, and a number of experiments are planned to determ ine what factors are involved and whether hydraulic or pneumatic cyclone treatm ent is the m ore feasible. CONCLUSIONS Data and observations obtained from the flotation tests to date have established that: (1) P la ty talc floats m o re re a d ily than nonplaty ta lc . (2) A frothing agent, such a s Dowfroth 200 is helpful in obtaining reasonable talc recovery. BATTELLE MEMORIAL INSTITUTE ctecf Docum ent-Subject to Protecfive Order JNJNLS1 000001S61 16 (3) About 13 p e r cent-.solids is the optimum feed pulp density fo r treating Italian N o,.2 talc, (4) E ith er Dextrin o r hydrochloric acid is an-effective rea g e n t fo r rejecting nonplaty talc. (5) When D extrin is u sed to d ep ress nonplgty ta le , the frothB produced a re voluminous and difficult to handle. When hydrochloric acid is used to regulate the pulp pH and depress nonplaty talc, the froths produced are norm al and w ill filter rapidly. (6) Italian No. 2 talc can be floated to yield a product which is m in e ralogically superior to Italian No. 1 talc. (7) O asis and Stone C reek types of o re s can be floated to yield products that approximate the quality of Italian No. 1 talc. It is believed that methods can be developed for these types of talc which will yield satisfactory products. (S) Flotation will re je c t som e of the objectionable fine ta lc , but m ore complete rem oval of the fines probably will require classification by hydraulic or pneumatic cyclones. FUTURE WORK Future experim ents would have as an objective a higher recovery of platy talc. Such experim ents would be based- on the use of hydrochloric acid to control the pulp pH and thereby the rejection of nonplaty talc while using different techniques of frother ad dition for im proved recovery. Flotation alone does not reject a sufficient amount of the particles which are po tential dust; th erefo re, experim ents would be m ade to rem ove these sises by hydraulic cyclones. A fter optimum beneficiation conditions have been obtained, it would be planned to produce enough product for various physical m easurem ents and also enough product to send to Johnson and Johnson for their subjective appraisal. We propose to investigate the feasib ility of n e a rly com plete rem o v al of dolom ite by leaching the float products with an inorganic acid. N early complete rem oval of dolo m ite would be n e c essa ry if it is im portant to obtain a talc product having a n eu tral pH. Flotation te s ts would be m ade on sam ples of Italian No. 2 ta lc which re p re s e n t different lots or shipm ents in order to establish that the beneficiation process is appli cable to any potential differences in s'ource m aterial. The o riginal notes on th e lab o ra to ry w ork d escrib ed in th is re p o rt a re in B attelle Laboratory Record Book No. 14265, pages 1 to 100, inclusive: and also in Laboratory R ecord Book No. 14666, pages 1 to 33, inclusive. The work was done in the period from D ecem ber 11, 1?37, to May 12, 1958. WEB:WL6:RDM/dpc A T T E L l'e . M E M O R I A L INSTITUTE Protected D ocum ent-Sublet to Proteeth Order JNJNLSIJXXKWT APPENDIX A DETAILS OF FLOTATION WORK BATTELLE Document-Subjoet to Protective Order MEMORIAL INSTITUTE JNJNL81_000001S83 A -1 and A- Z TABLE A-l. DETAILED RESULTS OBTAINED FROM FLOTATION OF ITALIAN NO. 2 TALC Anpiatjmli RuimUUsui, Maini Cauri, Fieli, Fiata- putidi palai Welfbt F" " 1" .... MIA tiro ________ Mini______ Ptr Dui#- imi- per TIim DONfroii FrolliCtnroctei Tul Prodict Cari Plily Nwplaly ulti ||li ut la Duttili CuHc-HCI ME Otfcii Sood Fili Fui Remsitu Flolriton IMI 1M.0 Feed No.2 631 u Filiali 65.S 36 12 FFilnuailii 21..91 a 3 <1 <1 13 1 2v n Fiori3 73 NeldetemlMd 15 FIMI 17.2 6 1 <1 13 14 FIMI S4.4 Natdatenained M IS FIMI MA SS 6 ci 1 13 FIMZ 16.6 92 6 1 1 16 FIMI 71.9 84 NO ND KB 13 rim i 19.0 Notdriwndntd 17 FIMI 97.1 9 FIMI2 73 91 Re- 36.0 96 S <1 <1 13 S21 3 <1 <S 13 eleiMi Odane! 56.5 Nridtleralmd 20 FIMI 66.6 Noideloimned 13 FIM2 n.7 Netditcnined 13 21-24 Fiorii 8.9 96 3 <1 <1 13 a Finali D8i2a.c5aidtilbeausi ari cm<ta2nlM<h1a 13 27 FIMI 750 Notcletnitttf U 2S-S a Fiorii s Dlsnriedbtcun munti biddiloitorricd 61.1 s 1 ,2 13 Fiori2 2B7 67 6 3 6- Fiorii 77.3 91 t 2 1 20 F1M2 122 HotdetemlMd 5 FIMI ILS .96 2 <1 T 10 Fieri! 7,7 SI 7 1 1 36 FIMI 51.0 Notditwnloid n Fiori2 27.6 Nri Ateiinlncd 32 FIMI 70.4 2 <1 i io FIM2 10.3 tilt diUtnlmd 31 FIMI S3.1 Netdtleimtd 3S Finali SU 99 <1 <1 <1 io Finii2 11.6 96 3 <1 <1 41 Finii 76.7 M d 2 1 io 41 FIMI 66.3 36 2 <1 1 io Fiori2 3.3 8 4 <1 <2 42 Oricium wcwst orcontnBlBittai <3-46 FIMI ffl.2 91 FIMI 14.3 96 1 <1 <1 2 1l ios UadK- 5.5 67 21 6 6 flaw T DTOeanledbecauseri cooUnfnitloi 46 FIMI sto Netdririalaed 10 Fleri2 142 MetAromiuri 49 Fleti 1 Ts be(Mitri, multi auecllonabli Fidai 2 SO Fiorii 02.1 97 Finali 143 SI SI Fini! 530 97 92-SS FIMI 57.0 09 F1M2 11.1 SS 5*M Som* 11 OS ri 2 Tute Trote 13 S <1 1 2 <1 <1 3 *2 <1 <1 19 3 <1 <1 3 <1 l 7 10 0.91 0 s 9 0 9 0 50 0 10 0.94 0 10 9.91 0 5 9.31 0 50 0 9 0 194 sS 0 0 0 147 s0 0 15 0 9.47 1S 0-47 111 $ 0.94 161 5 0.47 0 10 0.94 0 lo 0.16 0 is 0.16 0 3 0 104 s0 0 s 0 0.94 IO 147 0 50 0 10 0.47 0 5 0.47 0 10 0.47 0 0.94 0 10 NO 0 0 HO 0 0 00 70 0 50 0 M0 0 0 0 M0 0 30 0 10 9 0. S0 D 19 9 0 1D9 19 0 9 60 0 S0 0 10 0. 0 0 0.34 0 00 0X 0 0.31 0 X 9 0.17 0 X 9 0.14 0 0 0 134(>) 0 0.17 0 0 0.37 0 0 0.34 0 X 0 0.34 0 X 0 0.34 0 0.34 0 0 0 034 0 0 034 0 0 0.34 0 0 0.17 0 X 0 9.34 9 0 o il 0 9.17 0 0.34 0 0.34 0 034 0 114 0 0.34 00 0 134 9 0 0X 9X 0 fi D 0X 0X 0X D 117 0 ae t 0.9 0 0 an 109 9.21 IN 111 0 iti 0 0X OJOW 7 0X fii 0 0 0% 109 0 0 113 0X 0 fi 0 9 1.99 111 m o D 0.0 in o o: a 18 9 IN (UH 0 0.13 au au 0.30(C} X 0X 0X 9X 0X 0X 9X 9X 0X 0, X X Sant purily u fnd X Tip iterned loputpMIA X X X Fittemi ilckly X Sani puiltyta leed X Fiori 1trileeledIvice X Fiori 1rritoitedonce X X DepHMiroriTMll; tveiaii ol lour testi X i X PiedpidnintlyflM putiti Contri entroplrielrii end cnattRtnanlx X X EneroUontllyfondfiuta; ri eoitl Ieri pHri pnlpme 7.4 X X Ftlhied itpicBy fltterod npldly pNol palpa 7.6, llltmd slowly Ruteni 679producedbulf- Mond products Fintiti Ind nurenwnoririntd flou cyclone undriflow Urie/lbwlienTestsNu. 52-55 wawetonriideyelonmteifleand u llitilimM Hite: Somteilt n mteveleeiedalnurioiicillybraun Iuiinatlsfictatytrottidwutnlttlu h beam* mtt iicmeiywa t low. RiUtrta ant: Ouitibiisnail SyMnlysis It ilarii MdniiwfietiifedbyCllebnFelds IncffipertlMl Mdn Uune ol Dixliln603. Geritic IIMGemili Mill Indi nine I Rangun. HCl li Tcpoitedit pendipeilonel imeni fiele hydfoloiicetili WeblaberiMpei antni HCI. Oowfroth200il a wilenohAli liriN cMimenfactindbyite DowCbemial Conpany. Thedwricri fonila ioCHj-CIt-CHz-O-CjHs-O-CsMD-O-CHs. (I) PoWlri HO. le) ReatuU. OH (b) Ultimi *KT. (d) TeelMweimedeon(heuaAilbwproductri Tait!52-55, andiitbvpiye| LI pei ont litui u a at~i me lit Tests 52-5$. B ATTELLE MEMORIAL INSTITUTE acted Document-Subject to Protective Order JNJNL61_0000013B4 APPENDIX B * f r o t h flo ta tio n battelle memorial institute d D ocum ent-Subject to Protective Order JNJNL81_0000013*5 B -l APPENDIX B FROTH FLOTATION Froth flotation is a process of m aterial separation for solid p articles, usually fin e r than about ZOO m icrons hi size. The separation takes place in an a ir-w a te r m ix tu re , and is a re su lt of the adhesion of certain p articles to a ir bubbles and the wetting of other particles by the water phase. Whether a p article w ill adhere to the a ir phase and be floated, or be wetted by the w ater phase and sink depends on die character of its surface. M aterials that either ionize or hydrate in water are nonfloaters, and m ost m in erals are in this group. Sulphur, graphite, and talc are exceptions and a re called natural floaters. M aterials with a.hydrocarbon surface, such as solid paraffin, are not wetted by water and will adhere to air bubbles. A m aterial norm ally w ater wettable and nonfloatable can be made nonwettable and readily floatable by coating it with a monom olecular film of a paraffin-type chem ical (collector), which presents a surface to the a ir-w a te r m ix tu re essen tially this sam e as solid p araffin. The polar p a rt of the chem i cal causes the hydrocarbon chain (nonpolar group) to stick to the surface of the m ineral. The reagents employed in flotation, grouped according to their function, are fro th ers, collectors, and m odifiers. In the flotation of talc, however, collectors play no p a rt and are not discussed hre because talc has a naturally nonwettable surface. Frothers Frothers reduce the surface tension of the w ater and stabilize the air bubbles. The fr other m olecule is heteropolar: one part-of the m olecule has an affinity for w ater, and the other has an affinity for air. The m ost widely used frothers are pine o ils, cresylic acid, and various aliphatic alcohols. Substances with structures sim ilar to alcohols., phenols, ketones, or aldehydes are m ost suitable, but many other organic compounds are potential frothers. F rothers usually have only slight collecting p ro p erties, that is , they do not adsorb on m inerals in such a way as toiriake the surface nonwettable. Same outstanding ex ceptions are that certain frothers aid in the collection of talc, graphite, molybdenite, sulphur, and coal, and this fact has been used in the w ork done on Italian talc. M odifiers M odifiers a re chem icals which can be. used to affect the w ettability or nonwetta bility of a surface. They a re used m ost commonly in connection with collecting reagents, to modify the degree of surface action, so that species of m inerals m ay be separated with greater selectivity. M odifiers also affect the surface characteristics of naturally nonwettable m in erals such as ta lc , and can be used to increase the quantity of talc which w ill float under a given set of conditions or the quantity of w aste m aterial which can be prevented from floating. sattgllc tad Docum ent-Subject to Protective Order memorial institute JNJNL61JM0001366 B-2 M odifiers usually are inorganic reagents, but some organic ones are used also. Some of the common ones a re hydroxides, oxides, silica tes, carbonates, and phosphates of sodium or calciu m , m in e ra l acid*-, short.-chain organic a c id s, s ta rc h , d e x trin , gum s, and glues. Flotation Variables ijv ery o re contains a t le a s t a sm all quantity of- soluble s a lts , and the w ater used - for m illing, regardless of its puyity, qontains many kinds of ions. This m eans that every flotation system , before the addition of any reag en ts, contains literally dozens of ions which a re capable of competing for a place on the surface of m ineral particles'. A fter the .addition of collecting, frothing, and modifying reagents, this situation is further com plicated, and when the air is introduced, the oxygen and carbon dioxide of the a ir take th eir turn at altering the pulp conditions. In addition to the chem ical variables, th ere a re physical and m echanical variables in a flotation sy ste m , such as p a rticle s iz e , w ater to solid ra tio , spee.d of agitation', ' flotation tim e, place of reagent addition, type of machine used, tem perature, cell a r rangem ent, and sequence of m in eral flotation. The kind and quantity of slim e p resen t in a flotation pulp are also factors of importance. The combination of these chem ical, physical, and m echanical variables resu lts in a heterogeneous system of. such com plexity th at it defies the tim e-h o n o red m ethod of scientific investigation, which is , to change one variable while holding all others con stant. The change of any one variable simultaneously changes many others. For exam p le , a change in acidity (pH) by the addition of hydrochloric acid w ill not only change the concentration of hydrogen, hydroxyl, and chloride ions present in accordance with the laws of m ass action, but it m ay change the concentration of n early every ion p resen t in the pulp, and any one of these concentrations m ay be critical to successful flotation. In addition the change in acidity w ill affect the ability of the frother to produce a stable froth. ! Flotation as an A rt It is because of this inherent complexity that flotation b often referred to as an a rt rath er than a science. Successful results on any ore a re obtained only by an " a rtis tic balance" of the many variables. Actually, the picture is not so bad as might be sup posed, for the m ajority of the variables usually a re of m inor im portance and only five or ten m ust be studied -closely. This brief discussion of flotation variables is included to stre ss the point that each ore presents its own intricate system , and that the set of conditions which gives optimum resu lts for one ore m ay require modification for another. Laboratory.Flotation Procedure The flotation equipment used for these experim ents is the standard Fagergren L aboratory Flotation C ell of 500 gram solids nom inal capacity. It is a batch m achine, but it is known that the resu lts Obtained with th is type of equipment can be tran slated reasonably w ell in term s of larg e-scale continuous com m ercial operation. The BATTELLE MEMORI AL -f INSTITUTE Protected Document-Subject to Protective Order JNJNL61 0000013 B-3 and B-4 F agergren c a ll ia m ade up of &cylindrical glass bowl which w ill hold about 1.75 lite rs of pulp. The pulp is agitatad by a rotor which is placed concentrically inside a sta to r, both of which a re m ade up of m ultiple stainless steel rods in a rotunda configuration, As the rotor spins in the pulp, a p artial vacuum is created directly beneath it which draws a ir through a concentric shaft and discharges it at the bottom of the cell. As the air enters the pulp, it is expelled with great shearing force between the rotor and stator and becomes diffused in the form of minute bubbles in the pulp. The general laboratory procedure used for die flotation of talc samples was as fo llo w s: Pulverized talc and water w ere added to the flotation cell in the proportions that would give the desired per cent of solids. The ro to r was started and the pulp agitated until the solids w ere wetted. Selected reagents w ere then added and the pulp conditioned for a few m inutes. The air was turned on and the flotation period started. The m ineralized froth which form s on the surface of the pulp was shimmed off with a paddle for a specified tim e or until no m ore froth form ed. Additional reagents were added, if de sired , for increased recovery of talc. During the te s t, records w ere kept to show the type of w ater used, per cent solids, pH, quantity and kind of reagents, tim e allowed for conditioning and flotation, and other significant observations. If the froth, or float product, was not of the desired purity, some of the standard methods for improvement w ere:. (1) To d e c re a se the ra te of a e ra tio n , which d e c re a se s the r a te of froth overflow (2) To d e c re a se the p e r cent solids in the flotation feed (3) To use le s s pow erful froth& g reag en ts (4) To use a m o re effective d ep ressan t (5) To reflo at the fro th in a second-stage operation (6) To m ake the separation a t another pH lev el (7) To d e c re a se the tim e of fro th collection. Some of the methods used to increase the recovery of high-grade piety talc were: (1) To in c re a s e the ra te of a e ra tio n (2) To in c re a s e the p e r cen t solids in the pulp (3) To dew ater the underflow and rep e a t the te s t on the unfloated solids and at a relatively high per cent sSlide. battelle memorial institute I t e c te d Documsnt-Sutysct to Protective Order JNJNLS1_000001388