Silver and Platinum Separating

[Polishmonster]

Hello
I have an alloy that has the following:
XRF showed:
Ag - 62.56%
Pt - 24.92%
Au - 3.85
The rest is Cu.

I want to separate Silver from Platinum. That alloy has gone through electrolysis and this was left in the anode bag. Now I do not want to do electrolysis of this again because the bar weighs 300 grams.

I have read here on the forum that if I were to dissolve this in nitric acid then platinum and silver should follow. I have also read that platinum should not follow and stays as hard powder at the bottom. Many different answers I have read on the forum and do not really know what to do now.

Is there anyone who can help and recommend something?

With kind regards

 

[Lino1406]

1. Is this a 1-piece, metallic?
2. What was the starting point and electrolysis for?

 

[Yggdrasil]

Pt will follow Pd when dissolving in Nitric.
If that is true with Silver, I really don't know.
I hope one of the skilled masters can
chime in and give some sound advice here.
Interesting mix though.

 

[Polishmonster]

1. Is this a 1-piece, metallic?
2. What was the starting point and electrolysis for?

1. Yes 1 piece
2. Electrolysis or better said electrowinning was for silver. I started with 1,5 kg anode that contained more than 67% silver.

 

[nickvc]

My take would be to dissolve what I could in nitric which should leave the gold which you can filter off, this needs to be done once everything that can dissolve has, take the remaining solution and add HCl to form silver chloride filter and rinse well and then cement the Pt with copper, not as easy as it sounds as you need to agitate the solution from the start to ensure you recover the Pt.

 

[samuel-a]

The key word, is "some"

Yes, at these proportions, some of the Pt will dissolve in Nitric leach.
Once the Silver is removed from solution, you would be able to recover the Pt from the solution.

 

[Palladium]

9% copper left after running thru a nitric cell? You must have melted the left over anode with the powders?
Always leave things in powder form until you know what the final process is going to be. It's easier to process and separate that way. Yes some of the gold and pt is going to follow silver now.