# Palladium Purification Problem



## jeweler1 (Mar 24, 2018)

Palladium purification problem

Using the process described in Hoke's book on pages 176,177 (purifying Palladium)
I had redissolved Palladium Chloride (red salt) in 20% Ammonium hydroxide solution,
filtered it and precipitated it by adding HCL . Got lots of Palladosammine Chloride 
(Yellow salt) so far so good.
Because I had started with a mixture of metals containing Palladium and my goal was 
Pure Palladium I needed one more step to achieve this .I vacuum filtered it and washed it several times with distilled water .
Now I redissolved the Yellow salt in more Ammonium Hydroxide (with some heat ) and again added HCL . This time it took a lot more HCL to precipitate the Yellow salt (this is where I think I goofed) I should have used a pH indicator instead of just adding HCL . Anyway the Palladosammine Chloride formed as expected however the solution began to turn dark red??? The yellow salt remained (later washed and heated to make Palladium Sponge ) but the solution still contained a substantial amount of Palladium (tested with Stannous Chloride) .
My question is how do I get my Palladium back from this solution ?
It already has a lot of HCL in it . I did try some Ammonium Chloride but it just redissolved and turned red clear again.
Any suggestions?


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## Lino1406 (Mar 24, 2018)

Your last solution is basic or acidic?


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## Lou (Mar 25, 2018)

You let it get too acidic. Evaporate it and then bring to pH 7 and reacidify to 2.5.

Also keep in mind that Pd(NH3)2Cl2 will dissolve in aqua regia.

Traditionally, a well oxidized solution is heated for hours to turn Pd(IV) to Pd(II) and chlorine lost from solution due to the heat. Then Pt is precipitated. Gold and silver should have been removed prior.


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## jeweler1 (Mar 25, 2018)

The solution is Acidic with lots of HCL could I simmer it down to get rid of the acid? I did that to eliminate Nitrate when I added Ammonium chloride and Sodium chlorate to get Palladium chloride. Will this get the HCL down to a level where the Palladium will again precipate?


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