black palladium precipitate

[steeranoff]

bhi, I have precipitated yellow platinum from a cat, but
The palladium precipitated black with tiny sparkles I tested
It with stannous and proved positive for palladium. I've
Never heard of a black palladium precipitate what would
Contaminate be to yield black palladium?

 

[jimdoc]

What did you use to precipitate the palladium?
Was the cat all carboned up?
Jim

 

[steeranoff]

I used sodium chlorate. It wasn't all carboned up but I
Didn't roast it either so there had to be some carbon
In the leach.[/url]

 

[lazersteve]

The dark color likely indicates some sort of contamination.

Hoke discusses purification of the palladium salt on page 177.

Dissolve the colored palladium powder in ammonium hydroxide, filter, and precipitate with HCl added drop wise.

Steve

 

[steeranoff]

what sort of contamination could be?