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O F M I N I N G T H E UNIVERSITY O F BRITISH COLUMBIA V A N C O U V E R , C A N A D A 3 ^ ^ r - ^ U) IOSC OVER? OF COBALT from Concentrates Supplied by Kelovma Exploration Co. by James Z.G-. Hall A Thesis submitted in partial fulfilment of The Requirements for the Degree of MASTER OF JffiPLIED SCIENCE in the Department of METALLURGY The University of British Columbia April 1941 INDEX Page INTRODUCTION . . . . . . . . . . . . . . . . . . . . . 1 1. Treatment of Raw Concentrates Directly with Sulphuric Acid . . 3 2 . PRELMINART ROASTING-. (A) Low Sulphur, Low Arsenic Calcines. . . . . . 3 (B) High Sulphur, Low Arsenic Calcines 4 (C) Comparison of Calcines . 5 5. TREATMENT OF LOW SULPHUR, LOW ARSENIC CALCINES . . (A) Mainly with Salt and Sulphuric Acid 6 (B) Mainly with Sulphuric Acid 7 (C) Mainly with Salt 8 (D) Mainly with Hydrochloric Acid. . . . . . . . 8 4. TREATMENT OF HIGH SULPHUR, LOW ARSENIC CALCINES. . (A) Mainly sulphatizing roast aided by Sulphuric Acid 9 (B) Mainly sulphatizing roast aided by Salt. . . 10 (C) Mainly sulphatizing roast aided by Hydro-chloric Acid . . . . . . . . . . . 10 (D) Mainly sulphatizing roast 11 5. PRECIPITATION OF COBALT from LEACH SOLUTIONS . . . 11 6. SUMffiRY OF RESULTS 12 7. CONCLUSION 13 8. TESTING PROCEDURES . . . . . . . . . . . . . . . . 14 9. ASSAY PROCEDURES 16 10. TESTS . • 22 11. REFERENCES 64 12. AOENOWLEDGEMENTS . . . . . . . . . . . . . . . . . 64 PRODUCTION , • The Kelowna Exploration Concentrate consists principally of a mixture of Arsenopyrite (FeAsS) and pyrrhotite (Fe S ) containing x x X from 5 % to 10 $ of gangue (SiO ). In addition the concentrate con-tains the following elements* Au — — 1.1 oz/ton (approx) Ag 0.25 oz/ton " Cu — 0.6. - 1.4 % Co 0.6 - 0.8 % Now the gross value of this concentrate isr Au ™ 1.1 oz ® 35.00 —-• S3.50 Co — - • 0.6 % - 12#/ton @ 1.50 — - 18.00 Cu — 0.6 % - 12#/ton @ .12 1.50 58.00 — — 58.00 Returns when shipping the concentrate to Tacoma: Gross Yalue of Au plus Cu 40.00 Freight, Treatment, etc —- 16.00 Net Return '•- — 24.00 24.00 •Now Gross value including Cobalt >—— 58.00 Present Net Return —• •—-«— 24.00 Therefore, value available for Treatment 34.00 34.00 58.00 Thus i n considering a treatment method, i t ' s cost including Au and Co losses, overhead, amortization, etc., should be kept down to about $25.00 per ton i f a reasonable and certain profit i s to be shown. This research on the concentrates was undertaken with the following objects i n view. (1) to determine whether the Cobalt could be profitably-extracted i n a marketable form. (2) to determine whether a suitable recovery of the Au content could be obtained i n the course of the Cobalt extraction. The values contained i n silver and copper are of secondary importance and their recovery was considered as l i k e l y to parallel that of the other metals. TREATMENT OF RAW CONCTBNTRATES WITH STJLPHORIC ACID Preliminary work carried out i n the ore dressing and metallurgical laboratories of the Department of Mines and Resources in Ottawa during July and August 1940, under the supervision of Mr. F.A. Forward, indicated that treatment of the concentrate directly with hot strong sulphuric acid might offer a suitable solution to the problem of recovering both cobalt and gold from the concentrates. The f i r s t five (5) tests were devoted to this method of treatment and their general procedure and reasons are as follows: (1) Concentrate added to strong boiling H SO REASON: to convert cobalt, copper to water soluble sulphatesjat the same time freeing the gold so that i t may be cyanided. In attaining this result iron was converted to an undesirable water soluble sulphate. (2) F i l t e r the"Quiescent Mixture"while hot. • REASON: Arsenic interferes with the recovery of cobalt and this serves as one simple method of eliminating the arsenic because Arsenious Oxide (ASgOg) is soluble in hot acid. Moreover the. acid i s easily freed of the As 0 because i t settles out on cooling. (5) The Precipitate i s given an oxidizing roast below . 725°C. REASON: The undesirable water soluble iron sulphate is converted to insoluble iron oxide (Feg03) between 600 - 7B5°C. whereas the water soluble cobalt and copper sulphates remain unchanged. The best recovery from this series of tests was 93 fo recovery of cobalt. Further work on sulphatihg raw concentrates was dis-continued because an experiment on roasted calcines performed by Mr. Alfred G-. Lyle proved sufficiently attractive to warrant further investigation. PRELIMINARY ROASTING-(A) Low Sulphur, Low Arsenic. Low sulphur and low arsenic calcines were obtained by an oxidizing roast of the concentrates. These roasts were carried out under two different conditions. The f i r s t by placing the concentrates i n a moderately hot furnace (500-550°0.) and gradually raising the temperature up to between 750 and 850°C. The second by placing the concentrates directly into the furnace at 750-850° C. It was found the gradual raising of the temperature adversely affected the elimination of arsenic. These roasts were continued at the higher temp-eratures u n t i l completely roasted. (B) High Sulphur, Low Arsenic. High sulphur and low arsenic calcines were obtained by a reducing roast of the concentrates. These roasts were obtained by placing the concentrates directly into a hot furnace (750-850C.) and cutting short the roasting time; stopping when the arsenic flame died and cooling in a confined atmosphere. This type of roast may be properly described as a "reducing roast" because during the arsenic elimination the concentrates are enveloped by an atmosphere of arsenic vapor. For a comparison of the resulting calcines from this type of roast to the foregoing oxidizing roast note the following chart. CP ro H CO 82 CO H3 CD CO o CO CO CO CO CO CO CO CP CO H CO o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o =S OS P. H H H I—1 H CD Ol 03 O Ol O H H H H H I-1 »t* H CO CO 1—' Ol cr> o> CT> -<! O 00 CP -•a O Ol Ol -O -CI CP Ol o H H Ol O! Ol Ol <+ tJ P. CO 8 cp CO CP CP te-CP te-to CP la CP to la • • « • • . « * • • 03 Ol -a CO CP o CO CP CO 00 CO Ol 03 O o 03 00 CO O Ol O -a Ol S3 -3 Ol -a oi o 03 O O -a co oi H o o CJI o S3 Ol o 03 O O CO O o S3 Ol O S3 Ol G CO o o CO CP o CO o o 00 CO Ol Ol o o -a o o Ol Ol o 03 o o o H o H o o H CO H 1 1 I ! 1 1 ; ! 1 ( CP H Ol O CP o o o O Ol Ol Ol O Ol o H O o H Ol CO • • • • 9 « o Ol to CP Ol O o> Ol o> o> If. o o o o o o o H H o o m 9 » • 9 e • « • • « H H o a> CO CO O CO -a CO H H a> CD jr-> Oi S3 CO CO CO H H CO CO H> H o -3 to H H CO i ; O CO o o • • • • « « a • • » « to O CP o CP Ol CP H H CO CO to to If' CO -a CP to CP o Ol -v! Ol o CO CO o cr> te- O CO § 2 ? P. >-3 fej "? p. B1 1-3 Cfl H-• 3 CD I co CO o o 9 5 H CO § o I b Co co co o H> O to. CO F- O CO cf P O O (D H HiW Pi CD I-1  W O p. p tfl O F- CD W O CD P • II 4 O O g CD O g pj I—' CD CD :•: ^ p- pi J3-I* CD RP I i-3 O ci- P. CO H CO CP Ol Ol tJ1  o 9 1 p cn 4 Ol CO o • O H (C) Comparison of calcines. (1} Slowly oxidizing dead roasts, started at low temperature and finished at high temperature. These roasts gave moderately high arsenic and low sulphide sulphur. See Tests 14 and 18A. (2) Rapid oxidizing dead roasts entirely carried out at high temperatures. These roasts gave very low arsenic and low sulphide sulphurs. (3) Reducing roasts carried out at high temperature and cooled i n open atmosphere. These roasts gave low arsenics and moderately high sulphide sulphures (12%). See Tests 30A and 34A. (4) Reducing roasts carried out at high temperatures and cooled i n confined atmosphere. These roasts gave low arsenic and high sulphide sulphur (21$). See tests 40A to 44A inclusive. 6 TREATMENT OF'LOW SULPHUR, LOW ARSENIC CALCINES (A) MAINLY WITH SALT AND SULPHURIC ACID This treatment i n general was conducted as follows: (1) Mixed the preliminary calcine with varying percentages of salt and sufficient sulphuric acid to thoroughly wet a l l the calcine. (2) Roasted this mixture at a moderate temperature (500-550*0.) to allow the sulphuric acid and salt time to react and form primary sulphates. (3) Ground these primary sulphates to pass through an 80 mesh screen and gave them an oxidizing roast at temperatures varying from 600 - 700°C. This would break up water soluble iron sulphate into water i n -soluble iron oxide (Fe g0 3). For further details of this treatment method see the following tests: No. 8 No.9G2 No. 14G No. 141 No.160 N0.I8B 90 9G3 14D 14J 16H 19B 9D 10C 14E 14N 16J 20C 9E 10G 14F 140 17A 22G 9F 15 14H 16B 17B At f i r s t these treatments embodied the use of small percentages of carbon which were thought to help i n the elimination of arsenic by reducing the stable arsenic compounds to the more volatile areenious compounds. However there was not sufficient advantages gained by i t s use and so i t s addition was discontinued i n later treatments. Tests 14B, 14C, 14D, 14E, 14F and 14M show that good recoveries may be obtained by this treatment. For example in Test 14C the use of 5 fo salt and 80 % strong sulphuric acid and roasted not above 650° 0. gave 92 % water soluble cobalt. It should be noted that heating the primary sulphates from 550 to 650°C. decomposed the water soluble iron sulphate. This decomposition released sulphur trioxide which had a mild sulphating action; increasing the recovery of the cobalt and copper by forming additional water soluble sulphates of these metals. (B) MAINLY WITH StJLFHURIO ACID This treatment method was carried out i n general, as follows: (1) Added sufficient sulphuric acid to thoroughly moisten the preliminary calcine. (2) Roasted the mixture at a moderate temperature (500 - 550C.) to allow formation of primary sulphates. (3) Ground these primary sulphates to minus 80 mesh and gave them an oxidizing roast to break up iron sulphate to water insoluble iron oxide (FegO^). For details and results see tests: No. 10B No. 14B 10D 14ff 10E 20D 10F The best recovery that was obtained by this method was 82 % of the cobalt i n Test No. 20D„ (G.) MAENLY WITH SALT , This treatment method in general was simply a chloridizing roast. The tests were carried out at varying temperatures from 350° C. up to 650°C. For results and details see tests: •No. 6 No. 21D 9B 22B The best recovery obtained by this method was 72 % in Test No. 21D. Where the chloridizing roasts were carried out at temperatures exceeding 450°C. the recovery was very poor because the cobalt chloride was broken down to water insoluble cobalt oxide. (D) MAINLY WITH HYDROCHLORIC ACID This treatment in general was carried out as follows: (1) Calcine was mixed with sufficient hydrochloric acid to moisten i t thoroughly. (2) This mixture was slowly dried at a low temperature and roasted below 450° C. At this temperature any water soluble iron chloride formed i s broken down to water insoluble iron oxide (Fe 0 ) while water soluble cobalt and copper remain unchanged. For results and details see tests: No. 21B No. 22N No. 31B 210 24A 31C 21M 24B 33D 22G 240 32B This treatment gave f a i r recoveries of copper and cobalt especially i n Test No. 24A, where only 1G % hydrochloric acid was used, gave a 72 fo recovery of cobalt. This treat-ment i s particularly attractive because of i t s simplicity and the low temperatures involved. TREATMENT OF HIGH SULPHUR, .LOW ARSENIC CALCINES (A) MAINLY BYjSULPHATIZING- ROAST AIDED BY SULPHURIC ACID This treatment in general was a sulphatizing roast making use of the high,sulphide sulphur content of the calcines augmented by sulphuric acid. These roasts were carried out at moderately low-temperatures (350 - 450° C.) When sulphating action was complete the temperature was raised to 650°C. to break up any water soluble iron sulphate. For details and results see tests: No. 40D No. 40G-40E 40K It should be noted that the f i n a l roasting at the higher temperature to break up soluble iron sulphate resulted in higher cobalt recoveries as experienced i n the treatment of low sulphur, low arsenic calcines with salt and sulphuric acid. See page 6. The best recovery was Test No. 40E which gave 74 fo water soluble cobalt. ,(B) MAINLY'BY SIILEHAT1ZING ROAST AIDED BY SALT This treatment i n general was as follows: (1) Calcine mixed with small percentage of salt. 12 (2) Calcine given a sulphating roast at low temperatures 350 - 450° C. (3) Calcine given, an oxidizing roast at higher temperature (625°C.) to decrease soluble iron and increase soluble cobalt. For details and results see tests: No. 30C No. 41B No. 440 No. 45F 40H 42B • 44D 45G-40N 43B 44E 45B The best recovery was in test 40N which gave 90 fo recovery of the cobalt with but l i t t l e interfering water soluble iron. (0) MAINLY BY SOLFBATlZING- ROAST AIDED BY HYDROCHLORIC ACID This treatment i n general was carried out as i n foregoing sulphatizing roast aided with salt excepting that salt i s replaced by Hydrochloric Acid. For summary of results and details see tests: 30B, 540„ 34D. The best recovery was obtained i n Test No. 30B which gave 82 fo recovery of the cobalt. However an excessive amount of hydrochloric acid was required to attain this high recovery. (D) MAINLY BY SULPHATIZING-This treatment involved only the use of the high sulphide sulphur content of the preliminary calcines to effect a sulphating roast. This roast was carried out at a low temperature (550°C.) under a closely controlled atmosphere. "When the sulphating action i s complete the temp, is raised (625°C.) to effect the decomposition of water soluble iron sulphate,taking advantage of the released sulphur trioxide to give a "secondary sulphating" action. For details and results see tests: Ho. 40B No. 40F No. 45K 40C 45E The best test, 45K, gave 68 fo recovery of the cobalt. PRECIPITATION OF COBALT FROM LEACH SOLUTION The recovery of cobalt from the water leach solutions i s easily obtained by standard practise. In evidence of this tests No. 23, 23B, 23C were run and gave i n the order of 98 % recovery of the cobalt as cobalt carbonate. This i s easily converted into a marketable cobalt oxide product by caleing. There i s nothing to indicate that this phase of the work w i l l present any d i f f i c u l t i e s . SUMMARY OF RESULTS (1) Although good recoveries were indicated by treatment of raw concentrates with excess sulphuric acid, the complexity of this operation in comparison to the simplicity of treatment of roasted concentrates made this method very unattractive. (2) In the treatment of low sulphur, low arsenic calcines, the best recoveries were obtained by the use of salt and sulphuric acid. However, i n spite of the lower recoveries obtained by the use of hydrochloric acid alone, this treatment was more attractive than the salt and sulphuric acid treatment because of i t s comparative simplicity. (3) In the treatment of high sulphur low arsenic calcines the best recovery was obtained by the use of salt i n aiding the sulphating action. However, i n spite of the lower recoveries, s ^ ^ s s i = ^ f sulphating the calcines with the omission of any reagents, i s favored,because: (A) Simplified treatment. (B) Elimination of gold loss by chloridization, (4) The best treatment of the high sulphur low arsenic calcines by sulphating action alone, i s preferred to the best treat-ment of the low sulphur low arsenic calcines with hydrochloric acid because: (1) Simplified treatment. (2) Elimination of gold loss by chloridization. (5) Recovery of the cobalt from the leach solutions i s standard practise and w i l l offer no d i f f i c u l t i e s as shown by test No. 23. (6) Preliminary work on cyanidation of leached residues, indicated that no d i f f i c u l t y w i l l be encountered i n obtaining good gold recoveries, CONCLUSION From an analysis of the results embodied in this research, i t may be concluded that by a combination of reducing and sulphatizing roasts a practical and simple method of extracting the cobalt from the concentrates, at the same time freeing the gold so that i t i s amenable to cyanidation, i s possible. 14. TESTING PROCEDURES P i c t u r e d below i s a 13 K.W. e l e c t r i c r e s i s t a n c e furnace which has automatic temperature c o n t r o l . Nearly a l l the r o a s t i n g both pr e l i m i n a r y and su l p h a t i z i n g was c a r r i e d out i n t h i s furnace. Note the hole i n the back of the furnace through which the pyro-meter i s introduced. The s i l i c a t r a y commonly used i s s i t t i n g on top of b r i c k s but unf o r t u n a t e l y both are d i f f i c u l t t o d i s t i n g u i s h i n t h i s p i c t u r e . E x h i b i t No. 1 The p i c t u r e t o the l e f t shows the usual p o s i t i o n of the door when e i t h e r p r e l i m i n a r y or s u l p h a t i z i n g r o a s t i n g was being c a r r i e d on. E x h i b i t No. 2 The high sulphur low ars e n i c r o a s t s were u s u a l l y c a r r i e d out i n an open s i l i c a t r a y placed i n the furnace as per sketch below. The t r a y was immediately covered w i t h an asbestos board when withdrawn from the furnace. This gave the s o - c a l l e d "confined-atmosphere" t o the c o o l i n g c a l c i n e . S u l p h a t i z i n g r o a s t s on the c a l c i n e s were l a t t e r l y c a r r i e d out i n a s i l i c a t r a y which was p a r t i a l l y covered by an asbestos board as shown below i n the sketch. Cross S e c t i o n of Furnace 16. The l e a c h i n g of c a l c i n e s was c a r r i e d out i n a beaker as p i c t u r e d i n the l e f t of E x h i b i t No. 3. Note the heater t h a t the beaker i s s e t t i n g on and the mechanical s t i r r e r used f o r a g i t a t i o n of the pulp. No 5. The e l e c t r i c furnace p i c t u r e d t o the r i g h t i n E x h i b i t No. 3 might be n o t i c e d . This furnace was used f o r i g n i t i n g the f i n a l p r e c i p i t a t e s of the cobalt and sulphur assays, the procedures of which s h a l l now be given i n d e t a i l . ASSAY PROCEDURES I t i s f e l t that a complete e x p o s i t i o n of the assay procedures i s not j u s t i f i e d i n t h i s r e p o r t so only the bare o u t l i n e s are included. For f u r t h e r d e t a i l s on preparations of standards e t c . any textbook on assaying may be consulted. \ There i s i n many textbooks on assaying an a l t e r n a t i v e e l e c t r o l y t i c method f o r the assay of c o b a l t . I t might be worthy of note that t h i s method was t r i e d , but because of the i n t e r f e r i n g e f f e c t of manganese, i t was found u n s a t i s f a c t o r y . Weigh out 1 or 2 gms Ore or calcine. Add 10-15 c.c. HC1 - digest until oxides i n solution. Add 3-5 c.c. chlorate mixture, slowly evaporate to dryness and bake. Add 3-5 c.c. HC1, again take to dryness and bake. Add 1-3 c.c. HC1. Add 100 c.c. H20. & Gas with HgO for 5-10 minutes. Bring just to b o i l . Gas again with HgS for 3-5 minutes. F i l t e r - Precipitate to copper assay. Boil f i l t r a t e to eliminate HgS gas. Add 10-15 c.c. 3 % HgOg. Pour into 500 c.c. volumetric flask. Add ZnO emulsion to precipitate iron -'"'cool. Add HgO to 500 c.c. mark. F i l t e r off 250 c.c. into 250 c.c. vol. flask. Transfer to 400 c.c. beaker. Add 6 c.c. HC1. Boil u n t i l a l l Og expelled. Add 25-50 c.c. HAc. Add Nitrosobetanaphthol (10 c.c. of 10 % solution for every 25 Mg Co present). F i l t e r - Ignite precipitate (700-900 C.) Weigh as Co 30 4 Weight x 0.734 = weight of cobalt. (Nitrosobetanaphthol solution must be freshly prepared by dissolving the right amount of Nitrosobetanaphthol in glacial acetic acid.) •18. WATER SOLUBLE COBALT (W.S. Co) Weigh out 5 gms calcine. Add 100 c.c. HgO and boil 10 minutes and f i l t e r Add 3-5 c.c. HC1 to f i l t r a t e Gas with HgS gas etc. Proceed as in Cobalt- assay of ores. See A . ACID SOLUBLE COBALT (A.S. Co) ' Weigh out 5 gms calcine. Add 100 c.c. Hg0 Add 1 c.c. cone. HgS04 - Boil 10 minutes F i l t e r Add 3-5 c.c. HC1 to f i l t r a t e Gas with HgS gas etc. Proceed as i n Cobalt assay of ores. See A . COPPER Wash copper precipitate from cobalt assay into beaker using as l i t t l e water as possible. Add 5-10.. c.c. HN0 3 : Add 3-5 c.c. Bromine water Evaporate mixture down to a volume of 3-4 c.c. ^ Add 25 c.c. H20. Add NH^ OH until just neutral Boil off excess HB^ OH Add 1 c.c. HAc Add 1 gm (approx.) KI Titrate with standard sodium theosulphate solution. 19. SULPHIDE SULPHUR (S-S) Weigh out | to 1 gm of ore or calcine Add 5-10 c.c. HC1 - digest un t i l oxides in solution Add 5-5 c.c. n i t r i c chlorate mixture, evaporate to dryness and hake. Add 3-5 c.c. HC1 - evaporate to dryness and bake. Add 3-5 c.c. HC1 Add 25-50 c.c. HgO F i l t e r and wash precipitate well. - & Dilute f i l t r a t e to 300 or 400 c.c. - b o i l . Add sufficient boiling BaClg to precipitate a l l the sulphur. Allow to set on warm plate. F i l t e r and wash precipitate 3 or 4 times with hot 5 % HC1 solution and fi n a l l y 2 or 3 times with hot water. Ignite - Cool - weigh as BaSO^ Weight BaS04 x 0.1313 = weight of sulphur SULPHATE SULPHUR (SO^-S) Weigh out 1-2 gms calcine Add 50-100 c.c. HgO - boil, f i l t e r and wash precipitate well. Proceed as i n Sulphide Sulphur. See ft . IRON Weigh out \ to -|- gm of calcine or ore. Add 5-10 c.c. HC1 - digest until oxides in solution. Add 3-5 c.c. n i t r i c chlorate mixture, take to dryness and bake. Add 3-5 c.c. HC1, take to dryness and bake. Add 15-20, c.c. HOI and heat. A Add Stannous chloride solution drop by drop u n t i l a l l iron reduced and one drop i n excess. Dilute to 400 c.c. volume. Add 10-15 c.c. Mercuric Chloride solution Aid 10 c.c. Titrating solution % Titrate with standard permanganate solution. & Titrating solution consists of: 80 gms MnSO^ 165 c.c. H 3P0 4 160 c.c. H^SO, 2 4 850 c.c. HgO WATER SOLUBLE OR AC ID''SOLUBLE IRON (W.S. Te or A.S. Fe) Weigh out 5 gms calcine Add 100 c.c. water Add 1 c.c. H gS0 4 (only for A.S. Fe) Boil for 10 minutes - F i l t e r Evaporate to almost dryness Add 10-15 c.c. HC1 Add Stannous chloride solution drop by drop Proceed as in Iron assay. See A . ARSENIC Weigh out 4 gms calcine gm ore) Add 5-10 c.c. HC1 - digest u n t i l oxides in solution Add 3-5 c.c. n i t r i c chlorate mixture - evaporate to dryness and bake Add 3-5 c.c. HC1 - evaporate to dryness and bake Add 3-5 c.c. HC1 and warm unti l dissolved. Transfer to a pyrex flask with the aid of HC1. Add gm of NaBr and ^ gm hydrazine sulphate. Connect flask with a d i s t i l l a t i o n column. Have a th i s t l e tube entering into, and continuing to the bottom of, the flask; through which 25-50 c.c. of HC1 may now be added. D i s t i l l - catching d i s t i l l a t e in a 250 c.c. beaker 1/3 f u l l of cold water with t i p of condenser just below surface of water. When volume in the flask has been evaporated down to about 20 c.c. add 25 c.c. more HC1 and continue d i s t i l l a t i o n until volume in flask i s again about 20'c.c. Wash out condenser into beaker. Transfer contents of beaker to a 500 c.c. flask. Add a few drops of methyl orange Add NHjOH u n t i l just alkaline Add HC1 u n t i l just acid - cool completely Add 5-10 gms NaHC03 Add 10 c.c. starch indicator solution. Titrate to standard color end point with standard iodine solution. T E S T S TEST No. 1 150 gms cone, were added to an excess of strong boiling sulphuric acid to convert everything to sulphates. The mixture was filtered hot. The precipitate was roasted at 600 C. to 650 C. unti l a l l action seemed complete. The resulting calcine weighed 97 gms. Go in calcine •—— — — — « 0.5 % Co in water leach residue = 0.11 % Result: 78 fo Cobalt, water soluble. TEST No. 2 90 gms cone, were added to boiling HgS04 l e f t over from Test No. 1 (The hot acid from Test No. 1 was cooled and the re-sulting precipitate of AsgOg filtered off.) The mixture was filtered hot. The precipitate was roasted at 650 C. to yield 104 gms calcine. Total Co (Gal.-) — - 0.76 fo Co in water leach residue — — - 0.082 fo Result: 89 % Cobalt, water soluble. TEST No. 5 2000 gms cone, were added to sufficient boiling strong HgS04 to convert everything into sulphates. The hot mixture was fi l t e r e d . The residue was split into three parts, each part roasted separately un t i l a l l action seemed complete; as follows: CALCINE * - 1 2 3 700 C. 665 0. 665 C. Total Co —• • — 0.46 % 0.33 fo 0.30 % (Cal) W.S. Co 0.15 1o — 0.22 fo 0.18 fo A.S. Co 0.20 fo 0.24 fo 0.19 fo Co in t a i l s —•- • — — 0.24 fo 0.09 fo 0.11 fo 43 fo 7 3 f0 63 fo A 200 gms portion of No. 1 calcine was mixed with 80 gms salt and given a chloridizing roast. Total Co — — 0.55 fo W.S. Go — 0.24 fo A.S. Co — — 0.30 fo Co in t a i l s • -» 0.26 fo Result: 54 fo Cobalt, acid soluble. TEST No. 4 2: 1350 gms cone, were added to an excess of strong boiling HgSO^ to convert everything into sulphates. The mixture was fi l t e r e d hot. 470 gms of the precipitate plus 25 gms salt (NaCl) were roasted at 650 C. A 52 gm sample was cut from calcine and called A. The balance was mixed with an additional 25 gms of salt and given a further chloridizing roast to yield 405 gms calcine B. CALCINE* i Total Co — — — _ W. S. Co Total Fe — W.S. Fe' — Insols • • Total Cu >— — -Total As — Cobalt recovery A B G.60 f> — 0.7G fo 0.56 fo 0.63 fo 22 .3 fo 27.2 fo 5.1 fo 4.1 fo 3.5 f0 3.5 fo 0.48 fo 0.48 fo 3.5 fo — 3 . 4 fo 9 3 f0 . - — 9 3 fo TEST No. 5 1800 gms cone, were added to a large excess of boiling strong HgS04 to convert everything into sulphates. The hot mixture was filtered and the precipitate assayed as follows: Co .34 fo As : 0.3 fo Cu — .36 fo S - S — 2 . 0 fo Fe — 24.1 fo S04-S ~ — — 22.0 fo W.S. Fe 20.4 fo No further work was done on this test. TEST No. 6 416 gms cone, were given a preliminary roast in a tray at an i n i t i a l temp, of 550 C. and f i n a l temp, of 850 C. and yielded 250 gms calcine. The 250 gms plus 30 gms of salt plus 12 gms pyrite were roasted for two hours at 600 G. Final weight = 290 gms Result: Trace Cobalt, water soluble. TEST No.. 7 * i Some sulphated concentrate from Test No. 5 was roasted with. 5 fo carbon and again with 5 % carbon at 650 C. It was then given a chloridizing roast with 3 fo salt at 650 0. Results 75 fo Cobalt, water soluble. TEST No. 8 100 gms of cone, were given a preliminary roast at an i n i t i a l temp, of 550 C. and f i n a l temp, of 822 C. to yield 63 gms calcine. 50 gms of this calcine plus 25 c.c. strong HgSO^ plus 1 gm carbon plus 1 gm salt roasted at 650 C. Result: 80 % Cobalt, water soluble. TEST No. 9 2000 gms cone, were given a preliminary roast at an i n i t i a l temp, of 550 C. and f i n a l temp, of 800 C. and yielded 1190 gms calcine (9A). Result: Co(Cal.) — — 1.48 fo TEST No. 9B 250 gms 9A plus 30 gms salt plus 12 gms pyrite roasted at 625 C. and yielded 290 gms calcine (9B). Result: Trace Cobalt, water soluble. TEST No. 96.-' ) 100 gms 9A plus 5 gms plus 2 gms carbon plus 50 c.c. strong HgS04 roasted at 650 C. and yielded 124 gms calcine 9C.. Result: 90 fo Cobalt, water soluble. TEST No. 9D 100 gms 9A. plus 5 gms salt plus 2 gms carbon roasted at 650 C. Calcine cooled, screened, mixed with 50 c.c. strong HgS0^ _ and re-roasted at 625 C. Result: 93 fo Cobalt, water soluble. TEST No. 9E 100 gms 9A plus 5 gms salt plus 5 gms carbon plus 50 c.c. HgSO^ roasted for 2-g- hours at 625 C to yield 127 gms calcine 9E. Result:. 90 fo Cobalt, water soluble, TEST;No, 9F 100 gms 9A plus 5 gms salt plus 25 c.c. HgSO^ plus 2 gms 0, roasted for 2 hours at 640 G. to yield 109 gms Calcine 9F. Result:• 62 f> Cobalt, water soluble. TEST No. 9G1 100 gms Calcine 9A plus 2 gms carbon plus 50 c.c. HgS04, roasted for 6 minutes at 530 C. to yield 148 gms. Total Co 1.15 fo Total Fe 32 fo TIT.S. Co — — 1.06 f vr.s. Fe 6.7$ Result: .92 fo Cobalt, water soluble. TEST No. 9G2* i 140 gms 9G1 plus 5 gms salt, roasted for 15 minutes at 630 C. to yield 140.5 gms calcine. Total Go • 1.15 fo Total Ee 33 fo W.S. Go — 1.15 fo W.S. Fe — ~ 5.5% Result: 100 fo Cobalt, water soluble. TEST No. 955 130 gms 9G2, roasted at 640-650 C. to yield 92 gms calcine 9G3, Total Co • 1.46 fo W.S. Co — — 0.99 fo n 4 7 . 7 fa A # s . C o _ — 1 # 3 1 f0 i. As 1.3 fo WiSt.Te — — - T r . " Cu — — — 0.69 fo Result: 67 fo Cobalt, water soluble, 90 fo Cobalt, acid soluble. TEST No; 10 1000 gms cone, were given a preliminary roast at an i n i t i a l temp, of 550 C. and f i n a l temp, of 625 C. to yield 616 gms calcine 104. Total Co(Gal.) 1.36 <fo tr • 51.4 fo TEST No. 10B ' i 100 gms 10A plus 50 c.c. HgSO^ roasted at 625 C. Total. Oo(Cal.) — • 1.32 fo W.S. Go. 0.65 fo " Fe — 49.8 fo A.S. Co • 0.73 fo " Cu — - 1.02 fo W.S. Cu 0.28 fo A.S. Cu — . • 0.40 fo Result: 50 fo Cobalt, water or acid soluble. TEST No. IOC 100 gms of 10A plus 50 c.c. H gS0 4 plus 5 gms salt, roasted for 1^ hours at 625 C. Total Co(Cal.) - ~ 1.09 fo A.S. Co — — 0.66 n F e 43,1 f0 W.S. Cu 0.10 ; W.S, Co • • 0.25 fo' A.S. Cu 0.40 1 Results: 23 fo Cobalt, water soluble. 60 fo Cobalt, acid soluble. 7o lo 'lo TEST No. 10D 100 gms 10A plus 10 c.c. H gS0 4 plus 25 c.c. HgO, roasted at 650 C. Total Co(Cal.) — • 1.34 fo A.S. Co 0.37 fo »r Fe • 50.7 fo W.S. Cu — — 0.02 fo W.S. Co — 0.04 fo A.S. Cu 0.31 fo Result: 27 fo Cobalt, acid soluble. TEST No. 10E ' 100 gms of 10A plus 40 c.c. HgSO^, roasted at 650 C. Total Go (Gal.) 1.08 % W.S. Co ---~ 0.82 fo « Fe 40.8 fo A.S. Co 0.86 fo « A s . 4 > 7 % ¥ > s # F e _ 6 e 6 o70 W.S. Cu — — 0.48 fo A.S. Cu 0.56 fo Results: 76 fo Cobalt, water soluble. 80 fo Cobalt, acid soluble. TEST No. 10F 100 gms of 10A plus 40 c.c. strong HgSO^ were mixed and allowed to react at room temperature u n t i l they formed a hard cake. Total Co(Cal.) --- 0.75 fo n Fe — 28.3 fo W.S. Go •--— 0.56 fo Result: 75 f> Cobalt, water soluble. TEST No. IPG-50 gms 10A plus 25 c.c. H 2S0 4 plus 1 gm of carbon plus 1 gm of salt, roasted at 650 C. Total Co(Cal.) 1.13 % W.S. Co 0.91 « j e 42.8 fo A.S. Co (?)- 0.81 fo " As • — 3.0 fo Fe 4.0 fo 0.61 fo W.S. Cu — ~ 0.49 fo Result: 80 f> Cobalt, water soluble. TEST No. HA' > 1000 gms cone, were given a preliminary roast at V50 0. to yield 600 gms of HA. TEST No. 11B 100 gms 11A plus 10 gms carbon plus 10 gms salt plus 10 gms pyrite, roasted at 700 C., cooled and 50 c.c. H gS0 4 added and further roasted at 725 C. to yield 120 gms. Result: 90 fo Cobalt, water soluble. TEST No. 12 1000 gms of cone, were given a preliminary roast at 750 C.-820 0. for one hour. Weight of calcine 565 gms. Total Ee 54.8 fo ' . S - S — 0.86 fo Total As 0.64 fo S0 4 - S — 1.08 fo TEST No. 15 400 gms calcine from test 12 plus 8 gms carbon plus 200 c.c. H SO , roasted at 600 C~. for 10 minutes. Sulphates weighed 595 gms. Sulphates ground through 20 mesh plus 20 gms salt, roasted at 640 0. for i f hours to yield 557 gms calcine. Result: 80 fo Cobalt, water soluble. TEST Mo. 14 " 2000 gms of cone, were given a preliminary roast at i n i t i a l temp, of 550 C. and f i n a l temp, of 800 C. to yield 1155 gms calcine 14A. Total Co 1.50 fo S04-S — 0.72 fo n F e _ 54.9 fo S - S — 0.25 fo " As ----- — 2.64 f> Au(Cal.) — — 1.83 oz/ton « C u 1.40 f> TEST No. 14B 100 gms 14A plus 2 gms carbon plus 40 c.c. H SO., roasted at 550 C. for 15 minutes. Weight of calcine 150 gms. Total Co 1.06 fo W.S. Co — 0.98 fo n Fe • 37.2 fo A.S. Go — 1.03 % n As ~ • — 1.33 fo W.S. Fe . 7.4 fo n C u 0.69 ff! A.S. Fe . 13.2 '# s o 4 - S _. _ 12.40 fo W.S. Cu 0.62 fo Sr-S — „ 0.2 fo A.S. Cu 0.65 fo Result: 87 f> Cobalt, water soluble. 89 fo Cobalt, acid soluble. TEST No. 140 100 gms 14B plus 5 gms salt, roasted at 650 C. for 15 minutes. Weight of calcine = 96 gms. Total Co 1.06 % W.S. Co 0.98 % « Fe . ,_ 37.2 % A.S. Co 1.03 fo 1.33 fo W.S. Fe 7.4 . fo ir Cu • 0.69 fo A.S. Fe — — 13.2 fo so4-s :—. 12.40 fo W.S. Cu — 0.62 fo s-s ~ 0.60 fo A.S. Cu 0.65 fo Results: 92 f> Cobalt, water soluble. 97 fo Cobalt, acid soluble. TEST No. 14D 50 gms of 14 C , roasted at 680 C. for 1^ hours to yield 36 gms calcine. Total Co 1.45 fo W.S. Co o;.84 w. Fe — 49.5 foi A.S. Co 0.83 ;* tr As - - — — — 1.74 fo W.S. Fe Trace « Cu 0.92 fo A.S. Fe 0.80 fo so4-S 4.0 fo W.S. Cu 0.45 fo s-s •— 0.1 fo A.S. Cu 0.80 Result: 58 fo Cobalt, water or acid soluble. TEST No." 14E-* ' 100 gms 14A plus 2 gms carbon plus 7^ - gms salt plus 40 c.c. H so , roasted at 650 G. for 15 minutes to yield 149 gms sulphates. 2 4 Total Co 1.12 fo W.S. Co 1.01 $ it Fe 36.6 fo A.S. Co 1.01 fo ti As — 1.26 fo W.S. Fe 8.8 fo « Gu 0.67 fo A..s.; Fe 13.1 fo so4-S 12.70 fo W.S. Cu • 0.64 fo s-s - ___ 0,40 $ A.S. Cu — 0.66 fo Result: 90$ Cobalt, water and acid soluble. TEST No. 14F 100 gms of 14E, roasted for !§• hours at 688 C. to yield 73 gms. Total Co 1.43 fo W.S. Co - •  0.88 fo n Fe 49.0 fo A.S. Co • 1.23 fo tt As 1.68 fo W*S. Fe Trace n Cu 0.94 fo "A.S. Fe 0.7 fo so4-S _„_____._ 4.1 fo W.S. Cu 0.51 fo NIL A.S. Cu 0.91 fo Results: 61 f> Cobalt, water soluble. 8B fo Cobalt, acid soluble. TEST No. 14G > . 600 gms 14A plus 12 gms carbon plus 240 c.c. H SO , roasted at 550 C. for 15 minutes. Weight of sulphates = 895 gms. Total Co (Cal.) — 1.02 fo A.S. Co 0.81 fo Au — . — — 1.19 oz./ton Au (Cal.) - — — — 1.23 oz./ton Results: 80 fo Cobalt, acid soluble. 37 fo Gold loss. TEST No. 14H 823 gms of 14G plus 41 gms salt, roasted at 650 C. for 15 minutes. Weight of calcine = 837 gms. Total Co (Cal.) 1.0 % A.S. Co • • 0.86 fo Au (Cal.) -• 1.21 oz./ton 4u • — —•—• 1.08 oz./ton Result: 86 fo Cobalt water soluble. 10 fo Gold loss TEST No. 14 I 77 3 gms of 14H, roasted at 680 G. for i f hours to yield 660 gms. Total Co (Cal.) 1.18 fo A.S. Co — — 1.02 f> Au (Cal.) — 1.41 oz./ton Au --- — 1.20 oz./ton Result: 85 fo Cobalt water soluble, 14 fo Gold Loss. 35, TEST No-. 14J -596 gms 141, roasted for 2 hours at 680 C. to yield 530 gms. Total Co.(Est.) 1.40 fo W.S. Co 1.21 fo Total Ee — — 47.5 fo A.S. Go - — 1,26 fo Total Cu —•— —-- 0.90 fo W.S. Ee — Trace W.S. Cu —• • 0.65 fo A.S. Ee 1.15 fo A.S. Cu — — - — — 0,69 fo Au — 1.37 oz/ton Au (Gal.) — - — ~ — 1.59 oz./ton Result: 86 fo Cobalt, water soluble. 14 fo Gold loss, TEST No, 14K 200 gms of 14J were water leached. Approximately 10 gm sample cut from water leach t a i l s , Au ——•—»-——- 1.60 oz./ton TEST No. ML Water leach t a i l s from 14K were cyanided i n approx. 0,05 percent cyanide solution with protective alkalinity kept at 0.04 fo CaO. Period of agitation was 43 hours. Cyanide t a i l s weighed 142 gms. Au =--<p«25 oz./ton Result: 84 fo Gold recovery. TEST m. 14M 100 gms 14A. plus 2 gms carbon plus 40 c.c. H SO , roasted at 2 4 550 0. for 15 minutes. Cooled, screened and further roasted for !•§• hours at 680 G. and yielded 100 gms. Total Co (Cal.) 1.50 fo W . S . Co — — 1.15 $ W.S. Fe — 0.10 f> A.S. Co 1.26 fo A.S. Fe 2.9 fo Result: 76 fo Cobalt, water soluble. 84 fo Cobalt, acid soluble. TEST No. 14N 40 gms calcine 14M plus 3 gms salt, roasted at 620 C. for 15 minutes to yield 42 gms calcine. Total Co(Cal.) 1.45 fo . W.S. Co — — 0.17 fo W.S. Fe — Trace A.S. Co 1.19 fo A.S. Fe 1.70 fo Result: 12 fo Cobalt, water soluble. 85 fo Cobalt, acid soluble. TEST No. 140 40 gms 14M plus 3^ gms salt plus 2 gms primary sulphates 14B, roasted at 620 C. for 15 minutes to yield 44 gms. Total Co (Cal.) 1.41 fo W.S. Co • 0.33 fo W.S. Fe Trace A.S. Co : 1.17 fo A.S. Fe — 1.4 fo Result: 25 fo Cobalt, water soluble. 85 fo Cobalt, acid soluble. TEST No. 16 200G gms cone, roasted at 750 C. to yield 1202 gms calcine 16A. Total Co (Cal..) — 1.46 fo 11 As —--—--• 4.7 fo n S — 1.3 fo TEST No. 16B 600 gms 16A plus 300 c.c. H gS0 4, roasted for 15 minutes at 550 C. to yield 900 gms of sulphates. These sulphates plus 90 gms salt were ground - 28 mesh and roasted at 600 C. for 25 minutes. Final weight equal 935 gms. Total Co • 0.96 fo W.S. Co 0.79 fo t» •Fe — — ; 33.6 % A.S. Co 0.79 fo n Cu — 0.70 fo W.S. j e 6.7 fo W.S. Cu 0.64 fo A.S. 12.9 fo A.S. Cu 0.65 fo Result: 82 % Cobalt, water or acid soluble. TEST No. 160 875 gms 16B, roasted at 640 C. for two hours to yield 827 calcine. Total Co 1.00 fo W.S. Co - - — 0.90 tt y e 35.4 fo A.S. Co 0.90 « cu • 0.66 fo W.S. Fe • 4.7 W.S. C u — • 0.80 f, A.S. Fe 10.9 A.S. Cu • 0.63 f, Result: 90 f> Cobalt, acid or water soluble. TEST No. 16D 250 gms of 160 leached with 1000 c.c. of 3,50 fo HgS04 solution for one hour at 80 G. Residue weighed 111 gms. Total Co 1.00 fo A.S. Co 0.72 fo Result: 72 fo Gob alt, acid soluble. TEST No. 16E 250 gms 160 ground i n a pebble m i l l for -jr hour at 50 fo solids. Pulp acid leached with 1000 c.c. of 3.5 fo solution H^SO^ for l-g- hours at 76 G. Residue weighed 115 gms. Total Co — — » ~ 1 . 0 0 fo A.S. C o — — — 0.72 fo Result: 72 fa Cobalt, acid soluble. TEST No. 16F 227 gms 160 roasted for four hours at 640 C. to yield 185 gms calcine. Total Co 1.20 fo W.S. Go — — 1.03 fo »» Fe — 42.5 fo A.S, Co 1.04 fo M Cu — - — 0.79 fo W.S. Ee — — 0.10 fo »r A.s 2.1 fo A.S.. Ee — 1.9 fo W.S. Cu 0.64 fo SO -S — 4 6.7 fo A.S. Cu —--- 0.68 fo s-s 0.1 fo Result: 86 fo Cobalt, water or acid soluble. TEST No. 16G-125 gms 16F leached with 600 c.c. of 3.5 fo H gS0 4 solution for one hour at 84 0. Residue weighed 90 gms. Total Co — • : 1.20 fo A.S. Co — — 0.81 f> Result: 67 fo Cobalt, water soluble. TEST No. 16H -500 gms calcine 16A plus 10 gms carbon plus 225 c.c. H SO roasted 2 4 at 550 0. for 15 minutes. Cooled, ground - 100 mesh plus 57-|- gms salt, reroasted for five hours at 630 C. Final weight - 670 gms. Total Co 1.09 fo " Fe 37.3 f> n Cu 0.70 fo W.S. Cu 0.61 fo A.S. Cu 0.65 fo S04-S — - — — - 11.3 fo Result: 85 fo Cobalt, acid or water soluble. TEST No. 16J 348 gms 16H, reroasted at 680 C. to yield 282 gms calcine. Total Co 1.28 fo W.S. Co 1.04 fo n Fe • 45.6 fo A.S. 1.04 fo «i Cu — — 0.84 fo W.S. Fe 2.9 fo ? W.S. Cu - 0.68 fo A.S. Fe 0.20 fo ' A.S.. Cu 0.60 fo Result: 81 fo Cobalt, water or acid soluble. W.S. Co 0.93 fo A.S. Co 0.94 fo W.S. Fe — — 4.1 fo A.S. Fe ~ 11.8 fo S-S , o.8 fo TEST No. 17A 2000 gms cone., roasted at 850 C. for one hour. Cooled, somewhat, added 30 gms of carbon and reroasted at 850 C. for 15 minutes. Cooled added 57 gms salt and 750 c.c. H SO and roasted for six hours at 2 4 680 C. Final weight = 1345 gms. Total Co(Oal.). 1.31 fo TEST No. 17B 500 gms 17A, reroasted at 680 C. for two hours to yield 450 gms calcine 17B. 250 gms 17B leached for one hour at 80C. Total Co (Cal.) — 1.45 fo " CU 0.93 fo W.S. Co — 1.30 fo W.S. Cu 0.76 fo W.S. Ee • - — 0.07 fo Result:' 90 fo Cobalt, water soluble. TEST No. 18A 1000 gms cone, roasted at 500 to 550 for three hours. Then temp, raised to 650 C. for hour and f i n a l l y to 700 C. for 15 minutes. Final weight = 606 gms. Total Co(Cal.) — — 1.45 fo S-S — 0.1 fo tt A s — 5.6' fo W.S. As — 0.08 fo S0A-S — — — — 0.8 fo A.S. As — 1.42$ TEST No-. 18B 100 gms 18A plus 6 gms salt plus 50 c.c. H SO roasted for 2 4 20 minutes at 550 C. 10 minutes at 550 C. and f i n a l l y 4 hours at 690 - 700 0. Final weight = 108 gms. Total Co 1.44 fo W.S. Co — — — - 0.22 fo Result: 15 f> Cobalt, water soluble. TEST No. 19A 1000 gms cone, roasted at (800-825 C.) for one hour and yielded 570 gms calcine 19A. Total Co(Cal.) 1.54 fo S-S 2.43 fo « As — 1.06 fo W.S. A s — 0.05 fo S0A_s ——— 1.0 .fo A.S. As— 0.60 fo TEST No. 19B 100 gms of 19A were treated exactly the same and at the same time as 100 gms 18A were treated in Test No. 18B. Final weight = 112 gms. Total Co(Cal.) 1.37 fo W.S. Co — — ' 1.21 fo. Result: 88 fo Cobalt, water soluble. TEST No. 19C 100 gms 19A plus 45 c.c. HC1, roasted gently for one hour and finished at 350 C. for one hour. Final weight = 100 gms. Total Co(Cal.) — >- 1.54 fo W.S. Co — 0.65 fo Result: „ • 42 fo Cobalt, water soluDle. TEST No. 20A 2000 gms cone.j roasted at 800 C. for -ig- hour and at 830 0. for hours. Weight of calcine - 1135 gms. Total Co(Cal.) — — 1.55 fo « As — ~ — 0.56 fo Ferrous Fe — r - — - - - - : — 2.5 fo TEST No. 2QB 900 gms calcine 20A, roasted at 830 C. for 20 minutes and at 850 C. for 10 minutes. Final weight = 888 gms. Total Co(Gal.) — —-- 1.57 fo « As — — 0.58 fo n s ------ • 1.18 fo Ferrous Fe 0.20 fo TEST No. 200 300 gms of calcine 20B ground dry for 15 minutes plus 150 c.c. HoS0. p5.us 1 5 gms salt plus 10 gms carbon, roasted at 550 C. for 10 minutes. Einal weight — 480 gms. Total Co.(Est.) • 1.36 fo W.S. Co 1.26 n — 49.5 •fo A.S. Co 1.23 " Cu - — — 0.98 fo W.S. Fe 0.15 » as — 0.43 fo A.S. Fe 1.14 U.S. Cu — 0.90 fo A.S. Cu - — • 0,95 Result: 91 f> Cobalt, acid or water soluble. TEST No. 20D 300 gms 20B ground dry for 15 minutes plus 150 c.c. H„S0,, roasted 2 4 at 550 0. and fi n a l l y at 700 C. for l i hours. Final weight = 506 gms. Total Co 1.55 fo W.S. Co 1.10 fo « C u ____ o.98 fo W.S. Cu 0.59 fo « j e 55.6 fo W.S. Fe — — 0.03 fo '». As 0.45 fo Result: 82 fo Cobalt, water soluble. TEST No. 2IA -5000 gms cone, roasted at 750 C. on floor of furnace for l i hours to yield 1685 gms. Total Co (Cal.) 1.57 fo " As • — — • 0.56 f> «• s 2.06 fo TEST No. 21B 100 gms calcine 21A plus 5 gms pyrite plus 15 c.c. HC1 plus 15 c.c. Ho0, roasted at 350 C. for f hour. Weight calcine =10.4 gms. Total Co(Gal.) 1.51 fo W.S. Co 1.11 fo Result: '74 fo Cobalt, water soluble. TEST .No.. 210. 52 gms of calcine 21B heated in beaker at 350 0. for one hour to yield 52 gms. Total Go (Gal.) — 1.51 fo W.S.. Go •• . . 1.05 fo Result: 70 fo Cobalt, water soluble. TEST No. 2H) 100 gms calcine 21A plus 5 gms pyrite plus 15 gms salt, roasted at 350 C. for 1-gr hours. Weight of calcine •» 119 gms. Total Co (Cel.) • 1.27 fo W.S. Co ---~ • 0.94 f> Result: 74 fo Cobalt, water soluble. TEST No. 21L 400 gms 21A, roasted for one hour to yield 381 gms. Total Co(Cal.) 1,65 fo » As - — ~ 0.40 fo n S . 1,13 fo TEST No. 21M 100 gms 21L plus 10 gms pyrite plus 15 c.c. HgO plus 15 c.c. l i d , roasted at 400 C. for one hour. Einal weight = 114 gms. Total Co(Cali) 1.45 fo W.S. Co 0.85 fo Result: 58 fo Cobalt, water soluble. TEST 21P * > 100 gms 21A, ground dry and leached for one hour with 5 fo sulphuric acid solution. Total Co(Cal.) --—• 1.57 fo A.S. Go — — ~ i,o f> Result: 64 fo Cobalt, acid soluble. TEST Mo. 22A - ' 4000 gms cone, roasted at 750 C. for one hour and five minutes on furnace floor with pyrometer in the calcine. Final weight = 2284 Total Co (Cal.) 1.54 fo TEST No. 22B 500 gms 22A ground dry plus 50 gms salt, roasted for one hour at 590-600 0. to yield 538 gms calcine. Total Co(Cal.) — — 1.43 fo A.S. Co — - 0.25 fo n As 0.41 fo W.S. Cu — — 0,48 fo W.S. Co • 0.15 fo A.S. Cu 0.80 fo Result: 10 fo Cobalt, water soluble. 17 fo Cobalt, acid soluble. 46. TEST No. 220 100 gms 224 plus 40 c.c. solution roasted at 450-500 0. for 2 hours. Einal Weight = 110 gms (solution:55 c.c. water plus 6 c.c. HgSO^ plus 5 gms salt). Total Co(Cal.) — — 1.40 fo W.S. Co 1.00 fo W.S. Ee t - 2.39 fo A.S. Co 0.77 fo Total Ee 49.0 % A.S. Cu — - 0.62 fo Result: 72 f> Cobalt, water soluble. TEST No. 22G 100 gms 22A plus 40s c.c. of solution and evaporate to dryness at 350 C. plus 20 c.c. more solution and roast for 2 hours at 350 C. (solution: 4 c.c. HC1 plus 2 c.c. H SO plus 52 c.c. HO to last 2 4 <3 18 c.c. portion added 2 c.c. more.H^SO^.) Einal weight • 104 gms. Total Co(Cal.) 1.48 fo A.S. C o — — 0.92 fo Total Ee • 52.0 fo A.S. Ee — — 4.3 fo Result: 62 fo Cobalt, acid soluble. TEST No. 22N 100 gms 22A plus 50 c.c. HC1, roasted for 2 hours. Total Co(Cal.) • 1.54 fo W.S. Co „ _ — » _ _ i . o i fo A.S. Co — • — 1.00 fo Result: 65 fo Cobalt, water or acid soluble. 47 TEST No. 23 200 gms Calcine 20 C. water leached I F i l t e r Ppt. to waste Filtrate made up to 1000 c.c. I 200 c.c. portion Heat plus 2 gms CaCO ~* ' Stir { 3 Ppt .A— : F i l t e r F i l t r a t e - 5 c.c. 5 J H O Heat plus 1 gm CaC0„ 2 2 S t i r Ppt.B— F i l t e r F i l t r a t e made up to 300 c.c. 25 c.c. portion-for assay 275 c.c. Filt r a t e - 1 gm CaCO^ —Heat, s t i r J Ppt.C- F i l t e r • • ' .. . Filt r a t e - 1 gm NaUOO- — —— Heat, s t i r Ppt.D ^. = F i l t e r F i l t r a t e - 1 gm Na_C0,, — • Heat, s t i r Ppt.E — F i l t e r J i F i l t r a t e - I f gm Na CO- Heat, s t i r ' J 2 3 Ppt.F — F i l t e r \ F i l t r a t e Product Additions Go Assays Cu Fe Heads 1.26 0.90 0.15 Ppt .A 2 gm CaGO 3 ___ 0.27 0.07? Ppt.B 1 gm CaGOg 0.39 Heads 1.25 0.24 — Ppt.C 1 gm CaCO^ o 0.19 — Ppt.D 1 gm Na CO & 2 3 0.87 Tr. Ppt.E 1 gm Na CO 2 3 0.37 Ppt.F 1.5 gm Na CO 2 3 Tr. F i l t r a t e Results: 98.5 fo Cobalt recoverable from leach solutions. 1 gm Na CO w i l l ppt. 2.0 gms Cobalt. 49. TEST No. 25B ' • zo C 200 c.c. portion of leached ^ treated similiar to Test No. 23 with the exception of additions which are shown below. Product Additions Co Assays Cu Fe Heads 1.26 0.90 0.15 Ppt .A 1 gm. CaCO 3 0.06 0.48? "• B Sfe gm Ca003 0.90 « 0 Fil t r a t e 2 gm Na GO 2 3 1.26 Tr. Result: 100 fo Cobalt recoverable from leach solution. I TEST No. 250 l : -. ' 1 50 gms of calcine 17B were treated similarly to test No.25 with the | exception of the additions which are shown below. Product Additions Co Assays Cu Fe. Heads 1.30 0.76 0.07 Ppt .A 3 gm CaC03 0.72 Tr. » B 2 gm Na CO 2 3 1.26 0.08 Fi l t r a t e Tr. Result: 98 fo Cobalt recoverable from leach solution. TEST No. 24A* j . 100 gms calcine 22A plus 9 c.c. HC1 plus 30 c.c. HO, roasted at 450 for 1 hour to yield 100 gms calcine. Total Co(Cal.) 1.54 fo n — ~ . 54.0 fo W.S. Ee — ; • 0,5 fo . W.S. 00 1.11 fo Result: 72 fo Cobalt, water soluble TEST No. 24B 50 gms of 24A plus 23 c.c. HgO plus 2 c.c. HC1, roasted at 350 C. to yield 50 gms, f i n a l calcine. Total Co(Cal.) — 1.54 fo A.S. Co • 1.07 fo A.S Fe — • l«.'ll fo Result: 69 fo Gobalt, acid soluble. TEST No. 240 100 gms calcine 22A plus 6 c.c. HC1 plus 2^ c.c. H gS0 4, roasted at 350 C. for -|- hour to yield 104 gms calcine. Total Co(Cal.) 1.48. fo W.S. Co — 1.01 f, Result: 68 fo Cobalt, water soluble. TEST No. 50A* ) 2000 gms cone.8 roasted at 800 0. for 40 minutes to yield 1207 gms calcine. Total Co(Cal.) — 1.45 fo «. Ee 62.0 f, » As — — — • 1.95 fo n s _ 12.2 fo TEST No. 50B 100 gms 30A plus 50 c.c. strong HC1 roasted at 350 0. for 1 hour. Einal Weight - 105 gms. Total Co(Cal.) 1.43 fo W.S. Co — — — 1,17 f, Result: 82 fo Cobalt, water soluble. TEST No. 50G 100 gms 30A plus 15 gms salt (added in aqueous solution) roasted at 550-600 C. for 1-jj? hours. Total Co(Est.) — 1.27 fo W.S. Co : 0.94 fo Result: 74 fo Cobalt, water soluble. 52 ® TEST NO. BI& " l 400 gms 30A roasted at 650 C. for •§• hour. Einal weight = 380 gms. Total Co (Cal.) 1.55 fo T o t a l s 2.62 fo W.S. Co — 0.31 fo S04-S — 1.05 % W.S. Cu 0.18 fo Result: 20 f> Cobalt, water soluble. TEST Mo. BIB 100 gms calcine 31A plus 30 c.c. HC1, dried slowly and roasted at &50 C. for -|- hour. Einal weight s 102 gms. Total Co (Cal.) 1.52 fo W.S. Co r 0.75 fo Result: 50 fo Cobalt, water soluble. TEST Mo. 510 100 gms 31A plus 15 c.c. HgO plus 15 e.c. HOI roasted on hot plate at 350 0. for g- hour. Final weight = 101 gms. Total Co(Cal.) — ~ 1.54 fo W.S. Go — — 0.64 fo Result: 41 fo Cobalt, water soluble. TEST No. 51D Same as test 31C except roasted i n furnace instead of on hot plate. Final weight - 101 gms. Total Co(Cal.) — 1.53 fo W.S. Co 0.92 fo Result: 60 fo of Cobalt, water soluble. TEST No. 52A • \ 110 gms calcine 30A, roasted at 600 C. for 6 minutes. Final weight = 105 gms. TEST No. 52B 90 gms of 32A plus 15 c.c. HC1 plus 15 c.c. H20, roasted for one hour at 4000. Final weight - 92 gms. Total Co (Cal.) — — 1.51 fo W.S. Co — — 0.88 % A.S. Co — 0.94 fo Brine Sol. Co • • 0.91 fo Result: 60 fo Cobalt, water, or acid, or brine soluble. TEST No. 54A. 2000 gms cone, roasted at 750 C. Roast stopped shortly after arsenic flame died down. Final weight = 1270 gms. Total Co — 1.39 fo T o t a l s - 13.18 % •S0.-S — • 0.61 fo 4 TEST No. 54B 500 gms 34A roasted at 650 C. for 15 minutes to yield 480 gms calcine 34B. TEST No. 34C 100 gms 34A plus 15 c.c. HC1 plus 15 c.c. HgO, roasted at 350 C. for one hour. Final weight = 99 gms. Total Co(Cal.) — — 1.40 f° W.S. Co 0.89 fo Results . , , , 53 f> Cobalt, water soluble. TEST No. 54D 50 gms 34B plus 7.5 HOI plus 7.5 c.c. H O , roasted at 550 C. for 35 minutes. Einal weight = 50 gms. Total Co(Cal.) 1.44 fo W.S. Co — 0.77 fo Result: 53 fo Cobalt, water soluble. TEST No. 55A 2000 gms cone, roasted at 825 C for one hour and a further two hours at 750 C. Einal weight = 1126 gms. A.S. Co ___..—_.> N i l TEST No. 37A 300 gms cone, roasted at 750 C on furnace floor until arsenic flame died. Approx. 30 minutes. TEST No. 40A 2000 gms cone, roasted at 810 C for 35 minutes - removed and cooled away from open a i r . Einal weight = 1165 gms. Total Co(Cal.) 1.51 fo S-S 21.32 fo Total As 0.56 fo SO^-S ~ 0.18 fo JEST No. 40B 200 gms 40A, roasted in open tray at 450 C for 30 minutes. Einal weight - 190 gms. Total Co (Cal.) — — 1.59 fo W.S. Co — 0.62 fo Result: 39 fo Cobalt, water soluble. TEST No. 4QG , 100 gms of 40A, roasted in partially covered tray at 450 0. for one hour. Final weight = 97 gms. Total Co(Cal.) -• 1.56 fo W.S. Co — - — • - — 0.88 fo Result: 54 fo Cobalt, water soluble. TEST No. 40D 100 gms 40A plus 5 c.c, H gS0 4 plus 10 c.c. Hg0 dried at 250 C, for one hour and roasted in partially covered tray at 450 C. for one hour. Final weight = 105 gms. Total Co(Cal.) 1.44 fo W.S. Co — • — — 0.94 fo Result: 65 fo Cobalt, water soluble. TEST No. 4QE • . 90 gms 40D reroasted at 650 C. for 40 minutes i n open tray. Final weight = 87 gms. Total 0o(Cal.) — — — 1,51 fo W.S. Co — ~ — • 1.11 f> Result: 73 fo Cobalt, water soluble. TEST.No. 40Fs 100 gms 40B reroasted at 625 C. for 40 minutes i n open tray. Final weight - 98 gms. Total Go(Cal.) — — 1,62 fo W.S. Co • 0.82 % Result: 50 fo Cobalt, water soluble. TEST No. 40G 100 gms 40A plus 15 c.c. H gS0 4 plus 5 gms HgO, roasted at 450 C. for l-k hours in covered tray. Final weight = 115 gms. Total Co(Cal.) — — 1.34 fo W.S. Co 0.60 fo Result: 45 fo Cobalt, water soluble. TEST No. 40H 100 gms 40A plus 15 gms salt, roasted at 450 C. for i f hours in covered tray. Final weight = 122 gms. Total Co (Cal.) •- -—- 1.24 fo W.S. Co ———— 1.00 fo Total S : •— 6.86 fo S04-S — — — — 6.54 fo Result: 81 fo Cobalt, water soluble. TEST No. 401 • 100 gms 40A plus 40 gms pyrite roasted for 2 hours at 450 C. Final weight - 110 gms. Total Co(0al.) — 1,37 fo W.S. Co — — . 0.83 fo Result: 60 fo Cobalt, water soluble. TEST No. 40J 100 gms 40A plus 5 gms Na gS0 4, roasted at 450 0. for l | hours. Final weight = 103 gms. Total Co (Cal.) 1.47 fo W.S. Co — 0.95 fo Result:-' 65 fo Cobalt, water soluble. TEST No. 40K 50 gms of 40G-, reroasted at 625 0. for 40 minutes. Final weight = 43 gms. Total Co(Cal.) — — 1.56 fo W.S. Co •• 1.12 fo S04-S 3.09 fo S-S — 0.32 fo Result: 72 fo Cobalt, water soluble. TEST No. 40L 50 gms of 401 reroasted at 625 C. for 40 minutes. Einal weight = 43 gms. Total Co (Cal.) 1.43 fo SO^-S 1.21 fo W.S. Co 0.86 fo 3-3 0.15 fo Result: 60 fo Cobaltj water soluble. TEST No. 40M 50 gms 40J reroasted at 625 C. for 45 minutes. Einal weight = 48 gms. Total Co(Gal.) 1.52 fo SO^-S 2.64 fo W.S, Co 1.13 fo S-S 0.30 fo Result: 74 fo Cobalt, water soluble. TEST No. 40N 50 gms 40H reroasted at 625 G. for 45 minutes, Einal weight = 43 gms. Total Co(Cal.) — 1.29 fo W.S. Co — — — — • 1.16 fo SO -S — ~ — 6.14 fo 4 s_s — 0.00 fo Total As • 0.40 fo Result: 90 fo Cobalt, water soluble, 59. TEST No. '41A 2000 gms of cone, roasted in the tray at 750 C. for 65 minutes. Final weight = 1465 gms. S04-S — 0.06 fo S-S-.— 21.04 fo TEST No. 41B 100 gms 41A. plus 15 gms salt, roasted at 450 C. for one hour and 20 minutes. Final weight = 102 gms. Total Co(Cal.) — 1.18 fo SO -S - 5.57 fo W.S. Go — 0.18 fo S-S — 0.47 fo •• • Result: 15 fo Cobalt, water soluble. TEST No. 42A 2000 gms of cone, roasted at 775 0. for 55 minutes. Final weight = 1180 gms. so4-s 0.11 fo •S-S — — : 19.59 fo TEST No. 42B 100 gms 42A plus 15 gms salt, roasted for l j hours at 450 C. Final weight = 120 gms. Total Co(Cal.) — — 1.24 fo SO^-S 6.00 fo W.S. Co — 0.91 fo S-S — 0.32 fo Result: 73 f> Cobalt, water soluble. •60. TEST No.'45A 2000 gms cone, roasted at 800 C. for 70 minutes. Final weight = 1155 gms. SO -^s ~ 0.11 . fo S-S — — 17.09 fo TEST No. 45B 100 gms 43A plus 15 gms salt, roasted for 80 minutes at 450 C. Final weight = 121 gms. Total Co (Cal.) — — 1.26 fo S04-S ~ — 5.90 fo W.S. Co — 0.91 fo S-S • 0.25 fo Result: 72 fo Cobalt, water soluble. TEST No. 444 2000 gms cone, roasted on furnace floor at 825 0. for 30 minutes. Final weight = 1180 gms. S04-S — 0.12 fo S_S 20.98 fo TEST No. 44B 500 gms 44A, roasted at 450 C. for 80 minutes. Total Co (Est.) 1.29 fo SO^-S — W.S. Co 0.88 fo S-S Result: 68 fo Cobalt, water soluble. — 3.98 fo — 0.17 fo TEST No. 44CT 500 gms 44B plus 25 gms salt, roasted for 60 minutes at 450 0. and for a further 2 hours at 725 C. Total Co(Cal.) 1.25 fo SO -S 4.20 4> 4 ' W.S. Oo •— Trace S-S • 0.27 fo TEST No. 44D 500 gms 44ft. plus 25 gms salt, roasted in muffle for 2 hours. ' Final weight = 580 gms. Total Co (Cal.) 1.29 fo SO^ -S 5.21 fo W.S. Co 0.97 fo S-S • 0.03 fo Result: 75 fo Cobalt, water soluble. TEST No. 44E 400 gms 44D, roasted at 600 C. for 50 minutes. Weight of calcine = 387 gms. Result i 43 fo Cobalt, water soluble. TEST No. 45ft. 4000 gms cone, roasted at 800 C. for 35 minutes. Weight of calcine = 2370 gms. TEST No. 45B 400 gms 45A plus 60 gms salt, roasted in partially covered tray for l£ hours at 350 C. and 1-| hours at 400 C. Weight of calcine = 524 gms. Result: 41 fo Cobalt, water soluble. TEST No. 450 400 gms 45A plus 53 gms NagCOg, roasted in partially covered tray at 350 0. for 3 hours. Weight of calcine = 483 gms. Result: 18.5 fo Cobalt, water soluble. 51 fo Cobalt, acid soluble. TEST No. 45D 400 gms. 45A plus 71 gms NagS04*7Hg0, roasted in partially covered tray for 3 hours at 350 0. Weight of calcine = 462 gms. Result: 24 fo Cobalt, water soluble. 46 fo Cobalt, acid soluble, TEST N6.45E 400 gms 45A, roasted i n partially covered tray for Sg- hours at 550 C. Weight of calcine = 400 gms.-' Result: 49.3 fo Cobalt, water soluble. TEST No. 45F 100 gms 45B, roasted at 620 C. for 45 minutes. Weight of calcine s 90 gms. Result: 89 fo Cobalt, water soluble. TEST No. 45G-375 gms 45B, roasted at 625 C. for 45 minutes. Weight of calcine = 332 gms. Result: 86 fo Cobalt, water soluble. TEST No. 45H 400 gms 450, roasted at 600 C. for 50 minutes. Weight of calcine = 597 gms. Result: 85 fo Cobalt, water soluble. TEST No. 45J 400 gms 45 D, roasted at 600 C. for 50 minutes. Weight of calcine • 392 gms. Result: 86 fo Cobalt, water soluble. TEST No. 45K 350 gms 45E, roasted at 600 C. for 50 minutes. Weight of calcine - 330 gms. Result: 68 fo Cobalt, water soluble. BIBLIOQRAEHT • "" Hayward, Carle R. - "An Outline of Metallurgical Practise". D. Van Nostrand,. 1940. Schnabel, Dr. Carl, - Louis, Henry. - "Handbook of Metallurgy". Second Edition - McMillan and Co., 1907. Liddell, Donald M. - "Handbook of Non-Ferrous Metallurgy". McGraw H i l l , 1926. AOEJOWl^G-EMENTS The bulk of the work embodied i n this report was discharged by F. A. Forward (B.A.Sc. Toronto), Professor of Metallurgy, and A. G. Lyle (B.A. Sc. Brit. Col.), Assistant in the department of Metallurgy, both of the University of British Columbia. It was a pleasure to have assisted i n this research and a great privilege to be allowed to record the results. To Mr. Forward I beg to record my respects, not only for his contributing most of his time and energy but even more important, to his successful direction of this research. To Mr. Lyle, my respects for his painstaking care and accuracy during a l l testing procedures.