Does copper only knock out gold or does it also knock out silver?

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Yggdrasil said:
It should be yellow or red then, never heard of grey.

Can you please list your process step by step and explain what happened at each step?
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I dissolved the relays in dilute nitric acid, but I didn't wait for the aluminum buttons to dissolve, then I added hydrochloric acid and a lot of silver came out of it, which I filtered off, used sulfamic acid, then filtered again and finally used ammonium chloride.
 
ólom said:
I dissolved the relays in dilute nitric acid, but I didn't wait for the aluminum buttons to dissolve, then I added hydrochloric acid and a lot of silver came out of it, which I filtered off, used sulfamic acid, then filtered again and finally used ammonium chloride.
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If you start to dissolve something which puts PMs in solution you need to dissolve all.
Al do not dissolve in concentrated Nitric, but will dissolve in dilute Nitric, so a lot of your Silver and Pd might have cemented on the Al.
It still do not explain why the precipitate is grey unless it is very dirty.
 
Yggdrasil said:
If you start to dissolve something which puts PMs in solution you need to dissolve all.
Al do not dissolve in concentrated Nitric, but will dissolve in dilute Nitric, so a lot of your Silver and Pd might have cemented on the Al.
It still do not explain why the precipitate is grey unless it is very dirty.
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I don't know why it's gray, I asked what color the pd is because I couldn't find the color gray in the book either. But now it doesn't matter, I'm very happy that I got more than 300 grams of silver chloride.
 
Yggdrasil said:
Ammonium Chloride, Copper cementing or Zinc cementing depending completely on how it was dissolved.
You don’t detox Nitric, it is always as toxic as it is.
But I guess you mean deNOx.
If you have dissolved it with excess Nitric I assume it is necessary.
Give us a bit more background and your questions should be easier to answer.
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In the book, I read that palladium cannot be precipitated from an AR solution with ammonium chloride, instead it says sodium chlorate.
 
Well, actually it is precipitated by ammonium chloride, but only when it is in a highly oxidized state. In the classic separation of platinum and palladium, the ammonium chloride is added and the platinum precipitates first. The solution should be decanted as soon as the precipitate settles because some palladian will start to precipitate as well. The sodium chlorate is added which further oxidizes the palladium. The more highly oxidized palladian complex is less so!uble so it then precipitates.

Dave
 
FrugalRefiner said:
Well, actually it is precipitated by ammonium chloride, but only when it is in a highly oxidized state. In the classic separation of platinum and palladium, the ammonium chloride is added and the platinum precipitates first. The solution should be decanted as soon as the precipitate settles because some palladian will start to precipitate as well. The sodium chlorate is added which further oxidizes the palladium. The more highly oxidized palladian complex is less so!uble so it then precipitates.

Dave
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Thank you for your answer
 
If I filter the palladium red powder with filter paper and wait until it dries completely, will there be no other dissolved metal left in it? Because I want to do it by dissolving it again with ar and cementing it with aluminum. I can't solve copper cementation.
 
ólom said:
If I filter the palladium red powder with filter paper and wait until it dries completely, will there be no other dissolved metal left in it? Because I want to do it by dissolving it again with ar and cementing it with aluminum. I can't solve copper cementation.
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Cementing PGM's on Copper need proper and intense stirring and ideally a warm solution.
PGMs have a tendency to passify the Copper, but bubbling/ stirring will break up that layer.
The purity of the powder is up to your processes and how complete you manage to separate the PGMs
Drying or not do not impact purity, at least not in a positive way, flushing/washing do however.
Cementing on Al or better Zn will drop all metals but if it is pure enough it should not matter.
I would probably go for Zinc though, since it is easier to dissolve the surplus after.
 
Yggdrasil said:
Cementing PGM's on Copper need proper and intense stirring and ideally a warm solution.
PGMs have a tendency to passify the Copper, but bubbling/ stirring will break up that layer.
The purity of the powder is up to your processes and how complete you manage to separate the PGMs
Drying or not do not impact purity, at least not in a positive way, flushing/washing do however.
Cementing on Al or better Zn will drop all metals but if it is pure enough it should not matter.
I would probably go for Zinc though, since it is easier to dissolve the surplus after.
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Thanks for the answer! Lou described another solution in this thread that would be very good for me. The only problem is if I filter it with filter paper and then scrape this dust off it? He also gave a link where it was scraped off with a razor blade. Unfortunately, I could not translate the page completely. Palladium, did I do this right? or what did I do?
 
I'm still not exactly quite sure of what you did, only am I sure that you did it incorrectly and that I have covered this in detail before on this forum. Once again:

Palladium is remarkably simple to process if you know what you're doing.

When you dissolve palladium up in aqua regia you will form H2PdCl6 which is a brown (actually it's quite yellowish on dilution) color. Your first thing to do is to drop the gold after everything has been sufficiently deNOxed (removal of nitric). After that you will have a solution containing either nickel or palladium, or a mixture of both depending on the source of the scrap. The nickel will be green, and the palladium brown. For 5 ounces of metal, evaporate down to about 500 mL of syrup. It will be heavy. Then heat this to blood temperature or perhaps a warm bath. Then either add a couple crystals of sodium chlorate or bubble in chlorine gas (bleach would probably also substitute in lieu of the others). Add in a saturated solution of hot ammonium chloride and you'll see an immediate precipitation. Place this in an ice bath and you will see a brick red, flocculent precipitate which is somewhat voluminous. This is your ammonium hexachloropalladate; filter this and rinse with cold saturated ammonium chloride solution and vacuum filter it (you'll be all day otherwise) onto a frit. This can be reduced many ways, but given your limited access to the more normal routes and probable lack of equipmen, you can reduce with heat. The salt will break down into ammonium chloride, and eventually HCl gas (look for white fumes). You do not want to use a torch!!!! Doing so will cause loss of values upon heating, they will go up as a gray smoke. Instead, put them in a shallow porcelain dish and heat from below and let it smoke. After no more gas or 'smoke' comes off, you'll be left with Pd sponge. Dissolve this up again and repeat the procedure and your Pd will assay 99,95% pure.

You do not ever need to have a gallon of volume for 5 ounces of scrap, no matter what type of scrap. Work in small volumes or you will throw money away.

As for your button, that is Pd. It's quality is dubious at best just based off your procedure and something about it doesn't look right. Anyway, you probably got some of it, but I'll bet not all of it. Remember, nickel oxidizes readily, Pd doesn't oxidize at its melting point because its oxide is unstable, much like that for gold and silver, both of which do not oxidize if they are pure.

If you're a visual learner and you want to learn a wee bit of chemistry and see this done by a chemist in an obviously professional lab (also instructions for platinum), please see this link:


Sciencemadness Discussion Board - Precious Metals Reclamation Thread (Photo Intensive!!) - Powered by XMB 1.9.11
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This is what Lou wrote.

Edit by Moderator to add the quote.
 
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Yggdrasil said:
Your previous post?
This describes a specific situation, is your situation the same?
So you have Pd as the only PGM in your feedstock?
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I copied Lou's post here. It's not the same situation. Yes pd is the only pgm. Lou wrote that the red powder can be converted into pd metal by heating, but I don't know how to get it out of the filter paper.
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ólom said:
I copied Lou's post here. It's not the same situation. Yes pd is the only pgm. Lou wrote that the red powder can be converted into pd metal by heating, but I don't know how to get it out of the filter paper.
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What is your plan for the metal powder?
Sell it or use it for fabrication?
If you are going to sell it as it is, just cut a way surplus filter paper and calcine it in the paper.
The filter paper should be ash-less so it will disappear during the calcining.
The resulting metal may be a bit brittle, but if you sell it, it will be refined further at a later point anyway.
 
Yggdrasil said:
What is your plan for the metal powder?
Sell it or use it for fabrication?
If you are going to sell it as it is, just cut a way surplus filter paper and calcine it in the paper.
The filter paper should be ash-less so it will disappear during the calcining.
The resulting metal may be a bit brittle, but if you sell it, it will be refined further at a later point anyway.
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Yes, I will want to sell it, but not yet, but when there are more. Can it be calcined together with the filter paper? I remember that the book says not to calcine together with the filter paper.
 
ólom said:
I copied Lou's post here. It's not the same situation. Yes pd is the only pgm. Lou wrote that the red powder can be converted into pd metal by heating, but I don't know how to get it out of the filter paper.
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When you copy posts, add them in a quote so we see where and who it comes from.
 
ólom said:
Yes, I will want to sell it, but not yet, but when there are more. Can it be calcined together with the filter paper? I remember that the book says not to calcine together with the filter paper.
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I don't remember for sure, but I have seen it done.
If it is not going to be used in fabrication the brittleness from the Carbon should not matter much.
 

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