Document nkk6MEy7pbdMRm2zOr3VqpJaz

Colorado School of Mines Research Institute February 22 1977 CSMRI Project 10704 P.O. BOX 112 GOLDEN COLORADO 80401 PHONE 303 279-2581 CSMRI Mr. William H. Ashton Johnson & Johnson Baby Products Company Research U. S. Route No. 202 Raritan NJ 08869 Dear Bill This letter is a report of the results of our examination of talc sample 228P The purpose of the examination to identify all minerals present to estimate the amount of each and to determine the distribution of Ni Co and Cr between talc and nontalc minerals SUMMARY In summary minerals identified in the sample at a level of less than 0.1 were magnesite dolomite calcite pyrrhotite pyrite pentlandite rutile chromite and magnetite Chlorite occurs at a level of approximately % Nickel cobalt and chromium all occur in solid substitution in the talc crystal lattice In addition nickel occurs as the mineral pentlandite cobalt occurs in solid substitution chromium occurs as the mineral chromite in pentlandite and DETAILS A heavy liquid separation at 2.8 specific gravity recovered 0.09 of the sample in the heavy fraction By ray diffraction this heavy fraction contained major 50 magnesite minor 5-15 dolomite and smaller amounts of pyrrhotite pyrite chlorite pentlandite and rutile Electron microprobe examination of a bulk sample identified calcite Electron microprobe examination of the 2.8 specific gravity fraction identified chromite and a chromium iron oxide probably magnetite Nickel was determined by microprobe examination to be uniformly present in all talc grains at a level estimated to be 0.1 to 0.2 In Mineral Industry Research JNJ 000247326 + COLORADO SCHOOL OF MINES RESEARCH INSTITUTE Mr. William H. Ashton Johnson & Johnson February 22 1977 Page 2 addition nickel occurs as the mineral pentlandite identified by ray diffraction and microprobe A method of selective chemical dissolution was devised to obtain quantitative data on the distribution of nickel between sulfides and talc Digestion of a bulk talc sample in hot 50 nitric acid was followed by total decomposition in hydrofluoric acid ray diffraction examination of the sample before and after the nitric acid treatment showed it to be unchanged e.g. talc plus chlorite Atomic absorption analysis for nickel from the two acid fractions 1. nitric acid soluble 2. nitric acid hydrofluoric acid soluble gave the following results Acid Solution Ni ppm Wt % of Sample Dissolved Comments 1 30 2 2,050 2.4 97.6 Nickel assignable to sulfides Nickel assignable to talc Cobalt was determined by microprobe examination to occur in solid substitution in pentlandite at a level of several percent However microprobe examination of numerous talc grains was unable to identify the presence of cobalt The selective dissolution solutions prepared for determination of the distribution of nickel were also analyzed for cobalt to determine its distribution as follows Acid Solution Co ppm Wt % of Sample Dissolved Comments 1 4 2 66 2.4 97.6 Cobalt assignable to sulfides Cobalt assignable to talc Chromium was determined by microprobe examination to occur as chromite and as a phase interpreted to be chromium magnetite Microprobe examination of numerous talc grains failed to detect the presence of chromium Since chromite is an extremely insoluble mineral a method of selective dissolution using 1. cold hydrofluoric Most of the weight soluble in nitric acid is probably assignable to carbonates JNJ 000247327 COLORADO SCHOOL OF MINES RESEARCH INSTITUTE Mr. William H. Ashton Johnson & Johnson February 22 1977 Page 3 acid for decomposition of talc and 2. hot mixed acids for total decom- position of all minerals gave the following results for chromium Acid Solution Cr ppm Comments 1 100 Chromium assignable to talc 2 440,400 Chromium in bulk sample A mass spectrographic analysis of 228P having a detection limit of 0.7 ppm was run in order to obtain information on the presence of a variety of elements at very low concentration levels The results are as follows reported as ppm by weight Li B F Na Mg 1 Si P 0.9 0.8 ~ 310 M M M M 38 S Cl K Ca Sc Ti V Cr 28 17 28 M 4 100 10 M Mn Fe Co Ni Cu Zn Ga Ge 50 M 130 M 4 16 1 < As Se Br Rb Sr Zr Mo Pb 4 << 0.4 0.9 3 <3 4 4 M = major constitu~e2n00t0 ppm or greater We have no further work in progress on 228P have any questions concerning this work Please contact me if you Very truly yours Krause Jeny Krause ; Projectss Mining Division cjm JNJ 000247328