Test for Silver in Solution

[Maniacop]

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

 

[Eamonn]

If you add a drop of Hydrochloric acid and it produces a white cloud then you have silver in solution.
It also works if you add a solution of sodiun chloride, table salt will do,instead of the Hydrochloric acid.

Eamonn

 

[Harold_V]

You might also consider inserting a small piece of copper wire that has been sanded lightly, to remove oxides. If there's silver present, you'll see it cement on the copper wire. It's a fast and easy test that doesn't offer much chance of confusion, unlike a white cloud, which may or may not be silver. When in doubt, perform both tests.

Copper is an excellent way to recover traces amounts of silver, assuming the solution isn't contaminated horribly. It was my routine to send such solutions to a plastic bucket in which I kept a reasonable amount of copper in large pieces. I'd also recover traces of platinum or palladium, which often are in solution with the silver.

If the solution is quite dirty, I preferred to recover the silver as chloride, so it would be well rinsed before converting to elemental silver. Yields a little better product, although you can also give cement silver a wash in dilute HCl in such a circumstance. All in all, what ever is most convenient or comfortable for you, as there is no right or wrong.

Harold

 

[Topher_osAUrus]

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.

 

[Harold_V]

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.

Wow! Somehow I missed the part about the solution having already been precipitated. Mea culpa!!
If the solution is a chloride, or has any chlorides introduced, it won't contain any silver that can be cemented.

Thanks, Topher, for catching my error.

Harold

 

[Topher_osAUrus]

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.

Wow! Somehow I missed the part about the solution having already been precipitated. Mea culpa!!
If the solution is a chloride, or has any chlorides introduced, it won't contain any silver that can be cemented.

Thanks, Topher, for catching my error.

Harold

Harold, I figured it was just a quick oversight. ..which happens to everyone. I have done it more times than i can recall.

I feel honored to be a part of the forum and able to contribute what little bit I can.

To hear (...read, in this case) a simple "thanks", makes it that much better. ESPECIALLY coming from one of the boards legend refiners-even if was something simple as an oversight/misread

So, thank YOU harold, for everything. One day I hope to be able to be on your level, and contribute that much more.

This place, and all the people that make it up are a gift

 

[Maniacop]

I thank you all for your answers. So sorry it took me this long to respond. Getting old stinks. (And having a house guest that won't leave is even worse) cough cough my brother cough. =Þ I am a very long-time reader, and medium-time member but everyone I have talked to or read have been fantastic! Hoping to have half the knowledge that many of you here have. If I ever do, I will be far ahead of most others in the refining world! Looking through all of the new members.... I feel sooo old!

 

[Maniacop]

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.

Excellent knowledge! I think I need to do some cooking!

 

[rickbb]

Wow, replying to your 6 year old post. Might be a new record.

 

[Yggdrasil]

I thank you all for your answers. So sorry it took me this long to respond. Getting old stinks. (And having a house guest that won't leave is even worse) cough cough my brother cough. =Þ I am a very long-time reader, and medium-time member but everyone I have talked to or read have been fantastic! Hoping to have half the knowledge that many of you here have. If I ever do, I will be far ahead of most others in the refining world! Looking through all of the new members.... I feel sooo old!

Welcome back
You know age are a state of mind so mornings I'm old and evenings not so much, a couple of cold ones even better
This thread has been dead for some time, it is 6 years since the last post.
Harold has more or less left us behind, so much has changed.

 

[Maniacop]

Welcome back
You know age are a state of mind so mornings I'm old and evenings not so much, a couple of cold ones even better
This thread has been dead for some time, it is 6 years since the last post.
Harold has more or less left us behind, so much has changed.

Thanks for the Reply and so sorry to hear about Harold. I have a lot to do so maybe I will keep things a little busy with my (The only stupid question is the one that you don't ask) Questions!

Brett

 

[Yggdrasil]

Thanks for the Reply and so sorry to hear about Harold. I have a lot to do so maybe I will keep things a little busy with my (The only stupid question is the one that you don't ask) Questions!

Brett

My wordings might have come out wrong, he is still alive as far as I know, but he left the forum, busy elsewhere.