Maniacop said:
Hey everyone,
I have a lot of batches of precipitated jars I have to go through. I was wondering how would I test for silver in acid? a drop of Nitric?
Also what would cause a false negative on a Stannous test with a known gold solution?
You guys are the best!
Thanks!
Brett
The bold face in quotes is what i will be addressing since Harold gave you excellent advice which should be your go-to-guide
What were the batches of material you processed?
What methodologies did you use?
What did you use to precipitate from solution?
I ask, because, if it was JUST nitric, THEN it could definitely have a good amount of silver, palladium and platinum depending on material.
If it was AR, silver doesnt really go into solution along with gold in great quantities, it tends to settle out as a grey sludge of silver chloride thats trapping your other values.
That silver chloride should be separated from valued, converted to oxide, then metal, then melted...always leave AgCl wet
Copious amounts of sodium metabisulfite will give a false positive on your stannous test. From a brownish to a black depending on HOW much extra is in there.
The excess SO2 can be driven off by heating the solution, once it is eliminated it can then be tested again.
Not knowing what you have exactly, i am more than inclined to tell you to do the copper test that harold told you.