Help in refining gold with palladium

[adoreman]

Hi everyone,
I have not been active in the forum recently. I would like to ask. How do you refine gold that contains palladium using the nitric acid method. I did a batch of gold scraps and was unaware that some had palladium content. I had a problem in precipitating the gold as the particles became too small and the gold particles floated in the nitric acid solution. Thanks

 

[nickvc]

If you dissolved and then precipitated all the gold then simply cement the Pd with copper which will leave you with a black powder which will be your Pd and any other PGM in your solution. This can take a little time so be patient and test before safely disposing of the spent solution.

 

[Charles Connor]

If just by the nitric method, the gold is NOT precipitated, HNO3 would just oxidize all the contaminats (metals) that were with the gold and the Au would be left in the bottom of your beaker, then proceed with the Pd...

 

[g_axelsson]

With the "nitric acid method" do you mean inquartation?

I recommend watching the tutorial that Sam made.
http://www.youtube.com/watch?v=1gjJNZtrUHo

The palladium will dissolve with the silver and can be recovered together with the silver. To refine it is another process, for example cement on copper -> melt, process in silver cell -> recover palladium from the slime.

Both processes are described in details in Hoke - Refining Precious Metal Wastes.

Göran