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- Mar 10, 2013
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- 122
I've found a small lead/silver sulfide vein/stringer system identified as such by test 52.
I'm curious, can I use the below (or some modification you suggest) subset and slightly modified version of test 52 to do a quantitative analysis?
TEST No. 52: Silver - Ag. Page 1 of 3
TEST A: In dilute nitric acid; precipitated by as chloride.
1. Use powdered mineral (or concentrates) size navy bean. (I'd use an accurately weighed amount, and adjust fluid amounts given below according to sample size. It seems to me, my result might be improved by roasting the sample after weighing and before proceeding)
2. Place in test tube with 1 cc nitric acid; 2 cc water. (Water must be free of
chlorine - See Test 50)
3. Boil for some considerable time to dissolve the silver.
4. Filter; let set until cold.
5. Re-grind filtered material and repeat steps 2-4 to ensure high rate of extraction - combine solutions. Repeat again, but this time add few drops of hydrochloric acid (or salt) to solution to confirm high rate of extraction. RESULTS: A. A white precipitate if silver (or lead). B. A milky or opal color if very low grade. C. A thick curdy mass if high grade. After high level of extraction is proven (ie, no milky color/precipitate from adding hydrochloric acid) proceed as follows:
6) Combine the filtered fluids.
7) Slowly add a few drops hydrochloric acid to solution and stir and settle until no more precipitate is formed. (Probably decant fluid and repeat to prove all precipitate formed)
9. Pour off as much liquid as possible without disturbing the precipitate in bottom
of tube.
10. Add 2 cc of water and heat to boiling.
RESULTS:
A. The lead chloride in the precipitate will dissolve.
B. The precipitate will contain silver chloride. What other metals would stay with the silver?
Confirm silver as follows:
11. Pour off water without disturbing precipitate.
12. Add 1 cc strong ammonia to precipitate. Shake tube slightly.
RESULTS: If silver, precipitate will now dissolve.
13. Add 2 cc of water.
14. Add 2 drops of nitric acid.
RESULTS: The silver will be re-precipitated. Question - is precipitate silver, silver nitrate, or silver chloride?)
15 Dry and weigh precipitate; calculate % silver (if nitrate/chloride); divide by starting sample weight to get percent silver in ore. Might there be anything else in the precipitate? If so what - I can run other of Dukes tests to see if such might be present in sufficient enough quantity to invalidate my rough assay.
Yes, I know this isn't a 'proper' assay. Still, I get the impression from running this quantitatively that there is quite a bit of silver in this ore. Having some idea if it's 2, 4,10, more % - and I'd do the same for the lead present - would give me some basis for experimenting/evaluating concentration techniques, and deciding if the prospect is worth more effort.
I'm curious, can I use the below (or some modification you suggest) subset and slightly modified version of test 52 to do a quantitative analysis?
TEST No. 52: Silver - Ag. Page 1 of 3
TEST A: In dilute nitric acid; precipitated by as chloride.
1. Use powdered mineral (or concentrates) size navy bean. (I'd use an accurately weighed amount, and adjust fluid amounts given below according to sample size. It seems to me, my result might be improved by roasting the sample after weighing and before proceeding)
2. Place in test tube with 1 cc nitric acid; 2 cc water. (Water must be free of
chlorine - See Test 50)
3. Boil for some considerable time to dissolve the silver.
4. Filter; let set until cold.
5. Re-grind filtered material and repeat steps 2-4 to ensure high rate of extraction - combine solutions. Repeat again, but this time add few drops of hydrochloric acid (or salt) to solution to confirm high rate of extraction. RESULTS: A. A white precipitate if silver (or lead). B. A milky or opal color if very low grade. C. A thick curdy mass if high grade. After high level of extraction is proven (ie, no milky color/precipitate from adding hydrochloric acid) proceed as follows:
6) Combine the filtered fluids.
7) Slowly add a few drops hydrochloric acid to solution and stir and settle until no more precipitate is formed. (Probably decant fluid and repeat to prove all precipitate formed)
9. Pour off as much liquid as possible without disturbing the precipitate in bottom
of tube.
10. Add 2 cc of water and heat to boiling.
RESULTS:
A. The lead chloride in the precipitate will dissolve.
B. The precipitate will contain silver chloride. What other metals would stay with the silver?
Confirm silver as follows:
11. Pour off water without disturbing precipitate.
12. Add 1 cc strong ammonia to precipitate. Shake tube slightly.
RESULTS: If silver, precipitate will now dissolve.
13. Add 2 cc of water.
14. Add 2 drops of nitric acid.
RESULTS: The silver will be re-precipitated. Question - is precipitate silver, silver nitrate, or silver chloride?)
15 Dry and weigh precipitate; calculate % silver (if nitrate/chloride); divide by starting sample weight to get percent silver in ore. Might there be anything else in the precipitate? If so what - I can run other of Dukes tests to see if such might be present in sufficient enough quantity to invalidate my rough assay.
Yes, I know this isn't a 'proper' assay. Still, I get the impression from running this quantitatively that there is quite a bit of silver in this ore. Having some idea if it's 2, 4,10, more % - and I'd do the same for the lead present - would give me some basis for experimenting/evaluating concentration techniques, and deciding if the prospect is worth more effort.