Document mmjgNaZG410E90kakwynej6g

# ATTACHMENT A D escription of Modified Method to R ev ise Proposed Section 1 2 1 .2006(c) (2) Determine the Nz of the talc. Place 1 m illigram of talc on a slid e . Mix talc with refractive index liquid w hich has an Nd value most nearly equal to Nz of talc (liquid should be equal to or slig h tly le s s than Nz in t a lc ) . Spread p articles e v en ly and place a cover g la ss (ca. 18 mm square) on the sam ple. F ibers counted by this method should meet the following criteria. (1) Length to width ratio of 3 or greater; (2) len gth of 5 jam ot greater; (3) w idth of 5 um or le s s . Count and record the number of asbestos fibers found in the 1 milligram sample as determ ined from a scan with a polarizing m icroscope at a m agnifica tion of approximately 400x. Chrysotile fibers w ill have indices less than the liquid in both extinction p osition s. Amphiboles w ill have indices greater than the liquid in both extinction p o sitio n s. Check the extinction and sign of elongation for tentative identification. For specific identification of asbestos fib ers, make additional mounts in appropriate refractive index liq u id s , and refer to the optical cry sta ll ographic data in the ta b le. A count of not more than 1300 amphibole ty p es of a sb esto s fib er s and not more than 100 c h ry so tile a sb e sto s fib er s per m illigram -slide constitutes the maximum lim it for the presence of these asbestos fibers in ta lc . These lim its assure a purity of talc at least 09.9 percent free of amphibole ty p es of asb estos fib ers and at least 99.99 percent free of chrysotile asbestos fibers. If 100 or more ch ry so tile fib er s are cou n ted , the 2V of talc should be determined from the interference fig u re. If this value exceed s 10 there is a p o ssib ility that talc is b e in g counted as c h r y s o tile . In th is c a s e , . the sample should be rem easured according to the above procedure in 1.574 refractive index liquid. Chrysotile fibers w ill have indices less than the liquid in both extinction p o sitio n s. u/ - ** ATTACHMENT B O p tica l Data fo r C h lorites O C h lo r ite s are 14A l a y e r - s i l i c a t e s w ith a w id e range o f ch em ica l co m p o sitio n s and an e q u a lly w ide range o f o p t ic a l p r o p t e r t ie s . The h y p o th e tic a l form ula w ould b e Mgg(OK)gSi^O^Q, Alum inium r e p la c e s s i l i c o n and m agnesium . F e r r ic and rerro u s ir o n r e p la c e magnesium. ' ' Nx E l Nz Fix . E l Nz 1 .6 0 6 . 1.615 . 1.670 1 .6 8 5 1 .6 4 1 1 .6 4 3 - - . 1.664 - 1 .6 6 2 ' 1 .6 6 2 " - ' '- 1 .6 2 0 - 1 .6 5 8 . 1.658 <1.63 >1.650 1 .5 7 0 - - 1 .6 0 0 - 1 .6 0 3 1 .6 1 0 - 1.661 - 1 .5 7 8 1..580 . 1.586 1 .5 8 0 1.581 . 1.589 1 .6 6 0 1 .6 6 0 1.606 1.618 1 .6 1 8 1 .6 2 1 . 1.619 _ 1.623 1 .6 2 2 1 .6 2 2 1 .6 2 6 ' - 1.625 1 .6 3 7 - 1.642 , ' 1.646 1.646 - - 1.655 1 .6 5 8 1.667 1 .5 7 2 1 .5 7 2 1 .5 7 5 1 .5 8 1 --. 1 .5 8 1 - 1.607 . 1 .5 8 6 -- - 1 .6 2 0 ' 1.595 1 .6 2 1 - . 1.625 E x t in c tio n - p a r a lle l or in c lin e d ; e lo n g a tio n - p o s it iv e or n e g a tiv e - Data from W.A. D e e r , R .A . H owie and J . Zussm an, 1 9 6 5 , R ock-F orm ing M in e r a l s , Longmans, London. . O p tica l Data For the E pidote M inerals The i n d i c e s , b ir e f r in g e n c e , and o p t ic a n g le vary a p id ly w ith co m p o sitio n , There i s a con tin u ou s s e r i e s from Ca^Al 40 m o l. % Ca^FegCOHjSigO^^ ( p i s t a c i t e ) . (OH)Si^3O 12 ( c l i n o z o i s i t e ) to. about Nx 1 .7 1 8 1 .7 1 2 1 .7 2 2 1 .7 2 2 1 .7 2 9 1 .7 5 4 1 .7 3 9 1.756 El 1.720 ` 1 .7 2 3 1 .7 4 2 1 .7 4 3 1 .7 6 3 1.772 . 1 .7 6 5 1 .7 8 9 Nz 1 .7 2 3 1 .7 3 5 1 .7 5 0 1 .7 6 0 1 .7 8 0 1 .7 9 5 1 .8 0 0 1 .8 2 9 2-. # -Ny E p id o t e c r y s t a l s h a v e th e Ny c o i n c i d i n g w it h t h e lo n g d i r e c t i o n , th u s the n eed les w ill appear to have p o sitiv e or n egative elon gation ' depending upon which s id e th ey are r e s t in g . They w i l l have p a r a lle l ex tin ctio n . D ata from A lexander N. W in ch ell and Horace W in c h e ll, 1 9 6 4 , E lem ents o f O p t i c a l' M in e r a l o g y , P a r t I I , John W ile y & S o n s , New Y ork. ' O p tic a l P r o p e r tie s o f K a o lin ite and C h ry so tile K aolin ite . * K a o l i n i t e i s a 7A l a y e r - s i l i c a t e w i t h t h e fo r m u la A l ^ ( 0 H ) g S i ,0 - g . The com position is su b ject to l i t t l e v a r ia tio n but w ater adsorbed between the la y ers a ffe c ts the o p tic a l p ro p erties. Nx L Nz 1 .5 6 0 1 .5 6 5 1 .5 5 3 -1 .5 6 3 1.559-1.569 * 1 .5 6 2 1 .5 6 6 *1.553-1.565 1.559-1.569 **1.553-1.563 -- (more w ater) 1 .5 2 6 1 .5 6 6 1 .5 6 0 -1 .5 7 0 ' 1 .5 6 8 1 .5 6 0 -1 .5 7 0 1.560-1.570 1 .5 4 3 E xtinction P a ra llel or In clin ed 1-3 C h rysotile E longation P o sitiv e . * 1 .5 4 2 1 .5 4 3 . 1.55 * * * 1 .4 9 3 ` 1 .5 0 4 1 .5 1 7 * * * 1 .5 0 8 1 .5 1 2 1 .5 2 2 * * * 1 .5 2 8 - 1 .5 5 9 1 .5 3 0 - 1 .5 6 4 1 .5 3 7 - 1 .5 6 7r * * * 1 .5 3 -1 .5 4 1 .54-1.55 * * * 1 .5 4 2 1 .5 5 5 * * * 1 ,5 4 2 1 .5 4 3 (c a lc .) 1 .5 5 5 P a ra llel . P o sitiv e ' Nx * * * 1 .5 4 6 ***1.546 * * * 1 .5 4 8 m. 1 ,5 5 0 1 .5 5 7 1 .5 6 0 # Nz 1 .5 5 7 1 .5 5 7 1 .5 6 0 3-- E xtin ction ' > . # E longation l - L ata from: N. W in ch ell and Horace W in ch ell,- (1 9 6 4 ), E lem ents o f O p tic a l M in eralogy, ' John W iley & S o n s , Inc,. , New Y ork. *W. A .' D e e r , R .A . Howie , and J . Zussm an, 1 9 6 5 . R ock-F orm ing M in e r a l s , Longmans Loudon. **R alph E. Grim , 1 9 6 8 , C lay M in e r a lo g y , M cG raw -H ill Book Co. , New Y ork. ***Federal R e g iste r , V ol. 38, No. 188. i A I I NVESTIGATION OF THE WINTERBORO TALC D E P O S I T S , TALLADEGA COUNTY, ALA. by Avery' H. Reed, J r . ^ CONTENTS I n t r o d u c t i o n and summary.................. A c k n o w led g m e n ts.......... ............................. - L o c a tio n and a c c e s s i b i l i t y ............. P h y s i c a l f e a t u r e s ................................... H is t o r y and p r o d u c t io n ....................... P r o p e r t y and o w n e r s h ip ....................... D e s c r i p t i o n o f t h e d e p o s i t s .......... C h a r a c te r o f t h e o r e l ......................... S a m p lin g and a n a l y s i s . 1 .................... . Work done b y t h e B u reau o f M ines M e t a l lu r g i c a l t e s t i n g ............... ........ Page 2 2 2 3 3 3 k 5' 5' 5 6 ILLUSTRATIONS . Fo llo w s * 1 . C ou n ty in d e x map, A labam a.............................................................. 2 . S k e t c h map o f s o u t h e a s t e r n p a r t . o f T a lla d e g a C o u n ty , sh o w in g W in te r b o r o t a l c a r e a .............................. 3* -Map sh o w in g p r o p e r ty o w n e r sh ip and l o c a t i o n s o f . d r i l l h o l e s ................................ .......................................................... L. V e r tic a l se ctio n s through d r ill h o les T .-132-T .-135 . and T .- 1 3 1 - T . - 1 2 2 .................... : ...................................................... 5 . V e r tic a l section s, through d r ill h oles T .-1 3 1 , . - T .-1 2 8 , T .-1 2 9 , and T .-13^ and T .-1 1 7 , T .-119A , - T .- 1 1 8 A , T . - l W , T .-1 3 3 D , and T .- 1 3 3 B .................. .. jo. ; .V e r t ic a l s e c t i o n th r o u g h d r i l l h o l e s - T . - 1 2 6 , ,T .-12% ' T .-118A , T .-1 ^ 9 , T .-1 2 0 , T .-136A ,. 136, and T .-1 2 1 7 . V e r tic a l s e c tio n through d r i l l h o le s T.-137C t o T . - 1 3 7 G . . . . . . .................................................................................... 8 . G raphic d r ill- h o le lo g s o f h o le s T . - l l t o T .-1 3 3 C .. 9 . G raphic d r ill- h o le lo g s o f h o le s T .-133U to T .-150A 2 2 V b b 6 6 l / M ining en g in e er , Bureau o f M in esf T u scaloosa B ranch. Report of In v estig a tio n s L66l / /* .CHARACTER OF THE ORE . The t a l c i s not, hom ogeneous fo r any a rea nor f o r any sam ple . In g e n e r a l th e d e p o s i t s c o n n lgo o f m a s s iv e b i l e t h a t c o n t g j n s varying am ounts o i r e a or y e lV o v c l a y J n t T n i t e l y ni::ed w i t h l t 7 in a v e n g e s e c t i o n t h r o u g h t h e d e p o s i t shows, from tn e su rfa ce down, red and y e llo w c la y , red and y e llo w c la y v i t h fragm ents o f t a l c , t a lc v i t h red or y o llo w c le y r e la t iv e l y pure t a l c , drown c la y , and d o lo m ite. These u n its are g ra d a tio n a l, v i t h no sharp c o n ta cts to d is tin g u is h them; th e co n ta ct b etveen t a lc v it h c la y /a n d r e la t iv e l y pure ta lc is e sp e cia lly irregu lar. . . The t a l c i s q u ite s o f t and i s in t e n s e ly fr a c tu r e d . Hone o f i t ap p ea rs to he su ita b le fo r crayons or oth er u se s th a t req u ire stren g th .' The t a lc from th e so u th d e p o s it i s h afd er and. lo s s fr a c tu r e d th an th a t from, th e n o r th depos i t . T h e 'ta lc ran ges in c o lo r from w h ite and cream to y e llo v , gray, and b lu e . No a p p r e c ia b le amount o f v h ite t a l c i s p r e s e n t, and an average sample from any la r g e a r e a g r in d s t o a l i g h t cream c o lo r . The s p e c if ic .- g r a v ity o f a r e p r e s e n ta tiv e sample o f th e n o rth d e p o s it v a s d eterm in ed a s 2 .c 3 , crushed and d r ie d , by B . H. Clemmons, m e t a llu r g is t , 'Southern E x p e r i ment S t a t io n , T u s c a lo o s a , A la . _ F e y mi n e r a l s o t h e r th a n t a l c and c l a y m in e r a ls a r e p r e s e n t . O c c a s io n a l quarts"str in g e r s and lim o n ita grain s are found, e s p e c ia lly near th e edges of the d e p o sits. ---- -- ---- 1 -. _ . I ' . SAMELBIG AND ANALYSIS . ". - Overburden v a s f is h t a ile d and c a r e fu lly lo g g ed ; vhen fragm ents o f t a lc were found, co rin g v a s sta r te d im m ediately and continu ed through th e t a lc 1 ' s e c tio n . H oles v it h lo v t a lc reco v ery were r e d r ille d . '\ C ores t h a t c o n ta in ed t a l c from h o le s t h a t shoved 5 f e e t or more o f t a l c v o r e c a r e f u l ly c le a n e d and a n a ly z e d f o r t a l c , F e2^ > AlgO^,, and CaO. Sample i n t e r v a l s from t h e c o r e s v o r e s e l e c t e d go a s t o d e t e r m in e t h e m a x i mum am ount o f h ig h - g r a d e t a l c p r e s e n t in e a c h c o r e . . . .' T a lc co res from h o le s th a t shewed l e s s than 5 f e e t o f t a l c or from . iso la te d s itu a tio n s were not a n a ly zed . T h e.-talc from th e se h o le s v a s g e n e r a lly lo v -g r a d e and th o ro u g h ly mixed v i t h c la y . ' .. , ^ T w enty-seven sam ples from 12 h o le s were a ssa y ed . Of th e 75 h o le s . ; d r ille d * ^1 p en etra ted t a lc or t a lc fragm en ts. WORK DONE .BY THE EUEEAU OF MINES . . . The B u reau o f M in es i n v e s t i g a t e d t h e W in te r b o r o t a l c d e p o s i t s b y d r i l - :'v l i n g 7 5 h o l e s t o t a l i n g 3370*^ f e e t . . . H oles w ere d r i l l e d w ith in and around th e tw o known d e p o s i t s , and w i t h in the area between th ese d e p o s its . , j 3571 5' - *- " ' , . - ! t I i' TT*"" T rrr- W7,* 1 GEOLOGICAL SURVEY OE ALABAMA W ALTER B. JO N E S , STATE g e o l o g is t (ok m v n ) CIRCULAR 16 I THE TALC DEPOSITS OE TALLADE COUNTY, ALABAMA BY LYNN McMURRAY TE N N ESSEE VALLEY AUTHORITY AND EDGAR BOYCES GEOLOGICAL SURVEY OV ALABAMA UNIVERSITY, ALABAMA 1041 W ET UM PK A PR IN TIN G CO. Printers and Publishers Wetumpka, Ala. 1941 t LETTER OF TRANSMITTAL University, Alabama March 25, 1941 Honorable Frank M, Dixon, Governor of Alabama, Montgomery, Alabama. Sir: I have the honor to transmit herewith the manuscript of a report entitled "The Talc Deposits of Talladega County, Alabama" by Lynn McMurray of the Tennessee Valiev Authority and Edgar Bowles of the Geological Survey of Alabama. It is requested that this be printed as Circular Number 16 of the Geological Survey of Alabama. Respectfully, STEWART J. LLOYD, %Asst. State Geologis GEOLOOICAL SURVEY OF ALABAMA BENEFICIATION OF TALC ORE FROM TALLADEGA COUNTY INTRODUCTION Tin's report deals with laboratory tests which were made on i talc ore from Talladega County, Alabama. These tests were in lonncction with an investigation of talc ores in the Tennessee Valley and nearby icgion in an attempt to prepare products which tonId be used in the ceramic, textile, paper, cosmetic, and other jsdu'tries requiring a high grade talc. Initial investigations showed t-'aat only some of these ores were amenable to beneficiation methods. The beneficiation methods which proved most applicable ticre froth flotation and acid leaching. Many of the talc ores were found to contain appreciable percentages of serpentine and chlorite, which prevented them from becoming white on acid leaching. The arid leaching removes only the soluble iron from the ore. All of tie talc ores, however, could be froth floated to a high purity, but aiily those which could be acid leached were suitable for refine ment to high quality products. As the Talladega County deposit could be acid leached, it ap peared that a laboratory investigation toward the development of a suitable flowsheet would be well warranted. CHARACTER OF THE ORE Three samples, totaling COO pounds, were taken from the de posit so that a reasonable accurate cross-section of the ore body vas obtained. The mineralogical and chemical analyses of these famples, shown in Table I, indicate the rather uniform character of the ore body. TALC DEPOSITS OF TALLADEGA COUNTY, ALABAMA 13 TABLE I Chemical Analysis of Talc Ore from Talladega County, Alabama Sample No. i ___ 2 ___ 3 ___ MgO SiO, 31.25 , 61.74 29.12 60.78 31.05 62.50 Fe26 3 AhCL CaO 1.60 0.50 0.22 2.12 1.98 0.42 FejOi, ALOj, CaO 1.80 Loss at 900 C 4.84 5.41 3.75 Mincraloyical Analysis of Composite Samples Sltou'ii Above Sample No. Talc Garnet Quart/ Iron Oxide Clay, etc. Composite (1, 2, and 3) 93% 2% 2% 2% 1% The talc as it occurs is surprisingly pure, but the presence of small amounts of garnet, quartz, and iron oxide prevents its use as a high grade talc product. A physical study of the talc ore reveals that the garnet is liberated at 100 mesh and the quartz at a much coarser sizing. The iron occurs in streaks, pockets, and coating on the crude ore lumps. Grinding to 200 mesh is required to liberate this iron so that it will come in contact with the acid during leaching. As es sentially all talc products require grinding to minus 200 mesh or less, tliis offers no additional treatment over that already necessary for marketable products. No serpentine or_ch.lorite or dark colored minerals, other than garnet and iron oxide, occur in the ore. % BENEFICIATICI TESTS The froth flotation problem was the separation of the garnet from the talc. The quartz and appreciable amounts of the iron oxide could be easily depressed in the flotation cell. With any reagent combination used, a small amount of garnet contaminated the concentrates. In the laboratory garnet was removed by a magnetic separator, but the necessary fineness and dry condition are against such treatment in commercial practice. The garnet is