# Palladium Recovery.



## Aristo (Jul 18, 2007)

I am not sure if this has been discussed, as you can see i am almost brand new here and the search didnt yield the info I was looking for.
Moderators , please be gentle.  
I have a large amount of aqua regia in which i hade digested various CPUs. I had extracted the gold successfully , however , i am getting a yellowish black color on stannous chloride which I concluded was palladium. I am now ready to assault the palladium.
Now DMG is quite expensive and tricky to use so I am looking to a cheaper and simpler alternative.
I had tried adding aq ammonia to the solution and the re precipitating back in ammonia. I ended up with a dark purplish ppt which felt heavy. 
It got lighter as it dried. Upon testing , the content of palladium was negligible. The assay lab didnt say what the material was. 
Thanks for any assistance.


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## Harold_V (Jul 18, 2007)

You may not have palladium at all. I suggest you secure at least a small amount of DMG----but use it strictly for testing----not for recovery of palladium. It produces so damned much precipitate that it's beyond a joke, and is very difficult to handle. The fact that it produces a huge amount of precipitate is exactly why it is the best test of all for the presence of Pd. It produces a brilliant yellow substance that is hard to miss, even when very scant. Hoke, in her book Refining Precious Metal Wastes, provides proper guidance for making the test solution.

I've commented before, but I'll do it again----DMG is also useful for determining the presence of nickel----it's a wonderful testing tool to have in your arsenal of supplies. 

Anyone that refines should become familiar with all of the metals one might encounter, even if they are not your objective. You may not care if they're there or not, but it's nice to know what is, to help in identifying unknown metals by eliminating those with which you are now familiar. 

The reaction you achieved may well not be Pd. Not saying it isn't, but minute traces of gold in a solution that is not well balanced, coupled with questionable stannous chloride, can yield strange results. A test with DMG would be very useful in this instance. 

One thing to consider: The platinum group will rarely precipitate from a solution in which it is not concentrated. If you had but traces of palladium, assuming you had any at all----your chance of recovering by conventional methods would not be good. You might consider recovering it with copper, which will selectively remove only metals of value, not the base metals you likely have in solution. You might also consider putting your relatively barren solution in a stock pot, where the values will be recovered on scrap steel, along with some of the base metals. By doing so, you'll concentrate the values from various solutions, with the possibility of recovering them when there is an abundance. They can be chemically processed, or you can run the residues in a furnace. 

Harold


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## Aristo (Jul 18, 2007)

Thanks for the comprehensive reply Harold.
I will get some DMG and see how that works out.
Would anyone be able to comment on the presence of PMG with regards to various ceramic CPUs?.


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