AP and Silver

Gold Refining Forum

Help Support Gold Refining Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
i asked the same question. i havent done the experiment yet but i will in a day or two.ill post what happens.
 
You can use anything on anything, no matter what you think is on it. The question is, will it work? If you're trying to dissolve silver in AP, it won't work.
 
You still haven't explained what exactly you are trying to do. I now assume you want to dissolve the copper base with AP without dissolving the silver. That sounds feasible. My question now is, what exactly have you done to prove that this plating is silver? It might be tin.
 
It a part out of a cd-Rom I just want to see if it is silver. If it is tin I just learn something.
 
jmdlcar said:
It a part out of a cd-Rom I just want to see if it is silver. If it is tin I just learn something.
It's usually not necessary to build a huge dam to determine if it will hold water, or not. That is normally determined by engineering and testing.

That applies to your question, too. No need to try the process to determine if you have silver, or not. Why not test to determine what you have? That's what wise people do, and it's dead easy (and reliable) to do. You'll learn something that way, too, and it will be something that will serve you far better than undergoing a long process that may or may not prove positive.

Harold
 
Rub it on a piece of paper, if you get a gray streak it is a soft metal like tin, lead or aluminum.
Add a drop of HCl on the surface, nickle or zinc will dissolve, silver not.
Add a drop of nitric acid, silver will dissolve. Add a drop of HCl right after. If it was silver you get the white precipitate.

... or then you could just use proper silver test solution just to be sure. 8)

Göran
 
I have wondered about this also. I have buss bars from circuit breakers that I know for certain are plated with silver over copper. I am going to cut the bars in half to expose the copper and put them in AP. i want to see if the silver will flake off the bars similar to gold fingers. I will post results in a few days.

IF this proves to work the next questions I have to find answers to are:

1. Can the washing procedure I use for gold be applied with equal results for silver?
2. Can the silver flake be melted as is or does it have to be cemented with copper first?
3. Without melting what would the purity be of the silver flake after proper washing to possibly sell as is like can be done with gold flake?

I am not looking for answers to these questions, I am just stating what my thoughts are as I proceed with this experiment.
 
For #1, you can wash it in HCL or sulfuric, but not in Nitric.

I can't answer #2.

With #3, you have the same basic situation with silver as that for which we use inquartation with gold - If you have over roughly 25% silver, the silver will protect the other metals from the acid and merely washing with acid (other than nitric) won't accomplish much; If you have under 25% silver, you'll end up with your silver as a metallic grey sludge at the bottom of the container rather than as actual flake. Neither of those really counts as a "problem", but don't think you can just rinse your sterling in HCl and get .999.
 
I also have not given it a go to see the results. I get alot of silver plated switch buttons on small electrical things with a switch. Most is copper so it should AP with gray sludge. Since it is copper in solution, it is already dropped from solution.
My guess, it would be a good cheap way of collecting silver. It would need to be incinerated and then processed in Nitric to refine alittle cleaner.
My untested opinion of course.
Let's hear from the ones who have already tried and see if feasible.
Please....

B.S.
 
yar said:
I have buss bars from circuit breakers that I know for certain are plated with silver over copper. I am going to cut the bars in half to expose the copper and put them in AP. i want to see if the silver will flake off the bars similar to gold fingers. I will post results in a few days.
That makes no sense at all. The copper in the buss bar is worth far more than the silver, and the only way you'll get the silver to release is to dissolve the copper.

Why don't you use the little trick I used to use to recover the silver? Use the plated buss bar to cement silver from silver nitrate. If you introduce silver nitrate that has a little extra nitric present, it will eventually dissolve the silver surface, and then be recovered on the copper. You get the full use of the valuable copper and recover the silver in the process.

1. Can the washing procedure I use for gold be applied with equal results for silver?
It most likely will result in acceptable results, depending on what your gold washing procedure is. Do remember, silver is not dissolved by HCl.

2. Can the silver flake be melted as is or does it have to be cemented with copper first?
Is it possible you are confused? One does not cement silver flake. If you have finely divided bits of silver, and there's no contamination present that won't be removed in the melting and fluxing process, all that need be done is to melt the silver. Cementing is accomplished by FIRST dissolving the silver in dilute nitric acid. No need to do that in the case of silver flakes.

3. Without melting what would the purity be of the silver flake after proper washing to possibly sell as is like can be done with gold flake?
Probably a lot like asking how big is a rock.
Depending on your washing capabilities, and the source material, you could have some quite pure silver, or not. I'd not speculate, due to the huge number of variables.

I am not looking for answers to these questions, I am just stating what my thoughts are as I proceed with this experiment.
That's ok, you got answers, anyway. Might prove to be useful. Or not.

Harold
 
Harold thank you for your response.

I am doing this experiment to satisfy my own curiosity. If it do not get results that are satisfactory, I can send out the buss bars and the contacts like I have done in the past to one of the members here.

I understand that the copper has more value than the plated silver but I can always recover the copper later when the AP gets saturated and I want to mix a fresh solution.

Unfortunetly nitric acid is unattainable where I am located unless you are a registered business. So using your trick to recover silver using silver nitrate with excess nitric is not feasable at this point.

To clarify my first question, when I said washing procedure I meant as in washing the silver flake not dissolved silver. Sorry for the confusion. I normallly wash gold flake by boiling in DI water, then a boil in HCL, followed by three rinses in warm DI water, three rinses in HCL and a final three rinses in DI water. I would use the same steps for the silver flake.

Yes I did get confused Harold in my second question as only dissolved silver in solution can be cemented using copper, my apologies.

My third question was more rhetorical as of course everything depends on how well any metal, gold,silver etc is recovered and refined to remove as many impurities as possible.

Thank you sir for your input and answers to my questions. I will post updates to this thread with my results good or bad.
 
Harold_V said:
That's ok, you got answers, anyway. Might prove to be useful. Or not/.

One thing I have learned here is that any input that is constructive is always useful. Thank you again sir.
 
yar said:
I am doing this experiment to satisfy my own curiosity. If it do not get results that are satisfactory, I can send out the buss bars and the contacts like I have done in the past to one of the members here.
The AP process works by dissolving the base metal. The buss bar is a lot of material to dissolve, which was my point, but you may be on to something. All depends on the ability of the AP to penetrate the silver plating. If it can, you may enjoy success. Looking forward to a report.

Given the same problem and I had no access to nitric, I'd be inclined to strip the silver with a sulfuric cell. No reason why that won't work.

Harold
 
As a thought, instead of cutting the bar in half, you might try scoring it with a utility knife (just the surface layer, you don't need to go very deep) into sub-cm-square regions. That would give the AP more access to release the silver, without needing to dissolve quite so much of the copper to accomplish the task.

Depending on the process used to make the bar and the thickness of the silver plate, you might also find you can just peel the silver off. If the manufacturer just cold-dipped it without bothering to chemically bond the two layers, you may have something not all that dissimilar from peeling a chocolate coin.
 
Here is another place you can use that waste solution, you have been waiting to deal with.

You can use the old waste solution, that old jug of copper chloride that has become more of an Iron chloride (from seeing to much iron in its use)

FeCL3 ferric chloride can etch copper in a two-step process:
FeCl3 + Cu --> FeCl2 + CuCl
Then
FeCl3 + CuCl --> CuCl2 + FeCl2

Silver normally will not dissolve in an acidic Chloride solution, as it oxidizes easily and forms a crust of silver chloride AgCl, which coats the silver protecting it from further oxidation.

But we can put some silver into a solution if we have a very High chloride content:
Silver chloride AgCl is fairly insoluble in water but if we heated it strongly in salt water NaCl (concentrating the solution) we can put some of the silver into the salt solution as silver dichloride soluble in the concentrated brine solution, upon dilution we would again get the insoluble white silver chloride {AgCl2 + H2O --> AgCl + Cl- + H2O} this is the similar to how we get a little silver in our aqua regia solutions.
AgCl + Cl- --> AgCl2

Ferric chloride heated with silver will etch the silver, this iron III chloride solution is aggressive when heated and concentrated, it etches silver plate slowly but effectively, and with plated silver it become very aggressive to the copper under the silver, the concentrated ferric chloride will hold some silver as AgCl2 and precipitate the rest as AgCl, it will also hold a lot of copper into solution as CuCl2 and CuCl, by dilution we can precipitate the CuCl and the little AgCl.

The CuCl white powders can be stored wet, and re acidified in HCl to make an etching solution of copper II Chloride later, leaving the little bit of silver as white powder
4CuCl + 4HCl + O2 --> 4CuCl2 + 2H2O

For the little bit of silver on buss bars or contact arms (silver contact removed) you can dissolve the silver with copper, the heavy bar will still have a lot of copper metal left you could sell as copper metal (you will dissolve a good portion of the copper weight though), for thin silver plate it will dissolve all of the copper.

Ferric chloride will also dissolve iron into solution if needed.

Do not expect to get much silver from buss bars, or from plated silver.

When your done with your waste solution, treat it and dispose of it properly, for those who have not studied how see dealing with waste in our safety section.
Butcher
 
Back
Top