Monolithic caps

[Oz]

I just thought it worth asking those of you that have processed these if you find it best to go after the Pd first with nitric then try AR to see if other PMs are present. If so are you using 70% nitric or do you find dilution to 35% helps?

Also wondering how you are dealing with the tin and lead that is invariably present if the caps came off of boards.

Thanks,
Oz

 

[lazersteve]

Oz,

Here's how I do it.

First grind with a good mask to keep fine particles out of your lungs (barium compounds).

Next extract twice with hot HCl, allowing 24 hours to to work between extractions. This is where the nickel and tin will get removed. Three extractions may be even better.

Wash throughly.

Extract with 50/50 nitric, AR, HCl-Cl, or AP to get the Pd. If the caps contain other precious metals then select the appropriate solvent for the metals in question.

This process is demonstrated on DVD #2 of my Platinum/Palladium DVDs which are going to be ready very soon.

Steve

Steve

 

[Oz]

Thanks Steve. I was aware of the barium compounds but it cannot be repeated too often on the forum.

I assume from this you have little concern for PGMs going into hot 31.45% HCl as long as there is no addition of H2O2?

Would not HCl-Cl, AR, or AP take all PGMs into solution? The reason I asked about the nitric first is that it would be selective for the Pd. That is as long as I did not have Ag that would allow Pt to be put into solution as well.

Many are looking forward to your PGM DVDs myself included.

 

[JustinNH]

I thought I read on here that hot HCL can dissolve some Pd... am I mistaken, or is the amount not significant enough?

 

[Harold_V]

I thought I read on here that hot HCL can dissolve some Pd... am I mistaken, or is the amount not significant enough?

Only the oxides.

Harold