# AP and Silver



## jmdlcar (Oct 30, 2011)

Can I use AP on parts that I think silver is on them? If so should I add heat?


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## Geo (Oct 30, 2011)

i asked the same question. i havent done the experiment yet but i will in a day or two.ill post what happens.


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## goldsilverpro (Oct 30, 2011)

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.


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## jmdlcar (Oct 30, 2011)

I'm going to try to recover the silver.


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## goldsilverpro (Oct 30, 2011)

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.


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## jmdlcar (Oct 30, 2011)

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.


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## Harold_V (Oct 31, 2011)

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


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## itmtrading123 (Nov 9, 2011)

Thanks for all to share your information hare...


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## g_axelsson (Nov 3, 2013)

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


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## yar (Nov 3, 2013)

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.


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## chlaurite (Nov 3, 2013)

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.


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## yar (Nov 3, 2013)

Thanks chlaurite for the info.


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## Pantherlikher (Nov 3, 2013)

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.


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## Harold_V (Nov 4, 2013)

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


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## yar (Nov 4, 2013)

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.


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## yar (Nov 4, 2013)

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.


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## Harold_V (Nov 4, 2013)

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


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## chlaurite (Nov 4, 2013)

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.


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## Pantherlikher (Nov 5, 2013)

Hmm... maybe on a large copper bar, you can shave the silver off with alittle copper. That way you would not have to dissolve all the copper to get the little silver.

B.S.


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## butcher (Nov 5, 2013)

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


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## yar (Nov 19, 2013)

I mixed a fresh solution of Ap, 100 ml hcl and 50 ml h2o2, and put one silver plated buss bar into solution. Within 24 hrs the bar was completely stripped of Ag which at first was in flake form and then formed AgCl. I believe this occurred due to it being a fresh batch of AP. The AgCl settled to bottom of beaker under the AP.

After reading the thread on conversion of Agcl via NaOH and Karo, I am going to follow lazersteves direction in that thread to convert over to AgO. My question before starting is once I decant the AP should I rinse the AgCl until all AP is washed out and then procede with attempting to convert to AgO? My instinct tells me to wash it to remove as much excess chlorides and base metals as possible before adding the NaOH. 

I hope I am heading down the right path here, but either way it has been fun no matter what the outcome and is a good learning experience for me.


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## yar (Nov 19, 2013)

chlaurite said:


> 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.



Yes I did score each side of the buss bar and after it was stripped there was a nice piece of clean copper left, which I was hoping for. The contact did not come off which I did not think it would since I believe it is brazed on. 

I also tried to peel away the plating but that did not work. I appreciate the input, thank you.


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## niteliteone (Nov 19, 2013)

The AgCl (?) needs to be rinsed until clean. Also check the filter trash for silver flakes.

I'm not sure what you have, but that is how I would deal with it. Also their is a way to test the silver chloride to verify that is, what it is.
It involves dissolving the chloride in NaOH and then re-acidifying it back to silver chloride. A little searching will help you find a thread that explains the process completely.


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## Richard NL (Dec 16, 2013)

butcher said:


> 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



Thanks butcher,
The amount of chloride present in water can be determined by adding a silver nitrate solution to the water, →Parts per million/micrograms per liter←.
Because it is pushed out of the solution.

Still there can be silver in aqua regia, and it is normally loaded with chlorides.
This was a mystery for my!
Thank you sir, for making that clear.

Please correct me if I'm wrong or made a mistake,i am still learning.
Best regards Richard.


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## butcher (Dec 17, 2013)

Richard NL,
It sounds like you understand it very well.


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## Pantherlikher (Dec 17, 2013)

A bit odd in thinking or novice in question.
Silver plated copper in fresh AP may disolve some silver and then drop as AP gets running.
After all silver is stripped off; Decant, water washes untill clear. Would running fresh HCL with a few drops of well used AP finish dissolving any copper left behind or would it go for Silver or do nothing?.

Also how about the silver plated nickle pieces. (newbie question) as it would pertain to silver plated.

Then there is the steel arms with copper then silver plated buttons.

Individually, this is definately not worth any major effort but things to ponder and would be nice to be in the same thread since we're here.

B.S.


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## butcher (Dec 17, 2013)

Silver really does not dissolve well in the (AP) copper II chloride solution, if the silver is very thin, or powders, you can get more of it converted to silver chlorides, but thicker silver parts just coat over with that silver chloride crust which protects the silver metal underneath the, basically silver is not easy to work with in a chloride solution, because of the passivisation of the silver metal.

As a way to remove silver in contact points, where I cannot cut away or de-braze all of the copper from the silver contact, and to save my nitric acid, I found I can dissolve both the copper and the silver (Or at least break the silver down to chlorides) in a solution of copper and iron chlorides (that old used AP solution).
I have found boiling hot solutions of concentrating iron chloride works well to dissolve copper and silver into solution, the hot concentrated High chloride solution with the agitation,will attack both copper and silver fairly well, and both copper I chloride, and silver chloride will precipitate as white powders when the cooled solution is diluted, HCl will dissolve the copper I chloride forming copper II chloride, leaving the silver chloride.

But as with most chemistry we do here, unless we dissolve all of the base metal involved, the more noble metal can plate onto or stick to the base metal, with plated spoons you have an awful lot of base metal to put into solution to recover a very tiny amount of silver from that spoon.

Also spoons or silver plated flat ware, can be made out of several base metals (normally to make the brass under the silver plating look white like silver), these other metals like zinc can push acids out of solution, or push metals out of your leach solution, basically making the leach ineffective where the spent leach will need replacing with a more fresh leach (copper/ iron chloride leach)to continue the operation...


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## BSGMiner (Aug 25, 2019)

Well, here's this weekend's attempt at adding 400ml of HCl + H2O2 to my accumulated mixture of silver & base metals, which I tried out my air bubbler on as well.




Is it usually that dark of an emerald green? What does that indicate?

In addition, I tried out a small crockpot to help evaporate a diluted HCl + base metals solution. Now that it's starting to cool, I can see a thin layer of whitish precipitate (Copper I Chloride?) in the bottom of the jar.


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## BSGMiner (Aug 26, 2019)

BSGMiner said:


> Well, here's this weekend's attempt at adding 400ml of HCl + H2O2 to my accumulated mixture of silver & base metals, which I tried out my air bubbler on as well.


Notice: Don't post right before midnight, or it won't show up in the New Posts section when everyone wakes up...


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## butcher (Aug 26, 2019)

The first picture we can see lots of iron oxides and or hydroxides in the stockpot.

The next picture of the darker solution, HCl, and oxygen will put iron and copper (as well as most base metals) into solution, the dark green comes from being saturated with iron and copper chlorides in solution (in a lower oxidation state) as CuCl and FeCl2, instead of the lighter green of CuCl2 and FeCl3, the bulk of white salts are most likely CuCl. (Rejuvenating your leach at this point with oxygen and a little HCl will put more of the white insoluble CuCl back into solution as CuCl2) and as the darker CuCl2/CuClsaturated solution oxidizes the CuCl into CuCl2 the solution will get a lighter green color (like the lower picture).

The light green solution looks to be more CuCl2, ready to dissolve more copper iron or base metals,
The white salts can be:

Lead chloride.
fairly insoluble in HCl or CuCl2 solution, but it dissolves in boiling hot water and will precipitate back out when wash water is cooled.

Copper I chloride.
Dissolves in HCl.

Silver Chloride.
insoluble in HCl or CuCL2 solution, insoluble in hot or cold water.
silver chloride is a very fluffy and light, so it can take some time to settle while dissolving the lead chloride above in hot water, so we need to let the fluffy silver chloride settle while keeping the solution very hot while dissolving the lead chloride, before decanting the lead chloride solution from the solids...
We could dissolve the silver chloride if we wished, (although I do not see any reason in this case), using ammonia which if not properly done (acidified) can make an explosive silver compound, or with sodium thiosulfate...

And any noble metal like gold.
Noble metals which will be insoluble in the CuCl2 solution or will not dissolve in hot water, will not dissolve in HCl...


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## BSGMiner (Aug 26, 2019)

butcher said:


> The first picture we can see lots of iron oxides and or hydroxides in the stockpot.
> 
> The next picture of the darker solution, HCl, and oxygen will put iron and copper (as well as most base metals) into solution...
> 
> The light green solution looks to be more CuCl2, ready to dissolve more copper iron or base metals...


Thanks for your assessment and suggestions.

I'm bubbling the first two jars again today to see if I can get some more of the precipitate to dissolve into solution.


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## BSGMiner (Sep 9, 2019)

Well, here's what I've been busy doing-->and the results:
1) Adding 100mL HCl into the copper chloride & bubbling some more air into both jars-->No noticeable difference
2) Evaporating my stock pot-->Resulting in an inch of copper and iron salts
3) Decanting my copper chloride from the silver jar-->400mL total
4) Using a $5 battery acid tester in my copper chloride-->1.1 specific gravity
5) Pouring the copper chloride into the stock pot remnants-->it dissolved it all and resulted in a 1.2 specific gravity


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