What is the method for parting palladium from copper?

[kurtak]

A long story about parting Cu from Pd.

About 45 years ago, we had 50,000 pounds of telephone relay scrap, including the weight of the steel shelving, with pure Pd contact points mounted to copper alloy relay blades. When we cut the points off the blades, they were trimmed as short as possible. I spent several days experimenting with methods to dissolve the copper base without even slightly etching the Pd.

Hi Chris

The rest of your post was a very interesting read (as usual)

A few years ago I got in a bunch of those same type points (a ton plus) & was able to actually part the Pd from the copper/brass & the silver using nitric

I posted about it here :arrow: http://goldrefiningforum.com/phpBB3/viewtopic.php?f=34&t=23091&hilit=contact+points#p242399

Kurt

 

[Palladium]

Long before i even thought about becoming a refiner i ran across a closed scrap yard loaded with equipment from Johnson Space Flight Center from the 1960's and 70's. Of course i got screwed out of a lot of it by a refiner! One of the items was what you were talking about Chris with the pd contacts. There were these carousals with arms like a rotisserie about 2 ft long. Some sort of manual relay switching. Each one had wheels with little fins or fingers about 3 inches long and made like a flap sanding wheel that had pd contacts mounted on them. Their must have been 1,000's of them. I cut contacts for what seemed like days and days. If i remember right each one weighted a 1/4 gram. The fins where thin like razors and would cut the heck out of you if you wasn't careful. Sure wished i had them today!

 

[goldsilverpro]

I remember trying nitric in several different strengths and temperatures. I used an AA to test for dissolved Pd. In every case, some Pd dissolved and, even though the amount was small, I wanted none to dissolve. The H2SO4/CrO3 was the only thing I tried that dissolved zero Pd. Also, it was probably as fast as the nitric.

 

[Cerber]

Cerber, welcome to the forum.

Please make your posts in English. Most of our members speak English, but very few speak Russian.

Dave

Thanks Dave. I will try. But I know English badly, the difficulty of communication is possible.
The forum very big, is a lot of information, sometimes information is simply useless for me, but sometimes techniques of my western colleagues become for me new and interesting. Besides I in increasing frequency should work with materials unusual for me. And you face them practically every time.
I hope that I will find answers to the numerous questions here. I will try not to disturb strongly silly questions for you.

 

[Cerber]

But, I realize that I will need to study anew. Because electronics materials with which it is necessary to work now even more often - for me are low-standard, and demand other methods of preparation, concentration and sedimentation.

 

[Cerber]

К чему такие сложности?
Не проще ли растворить самородок и восстановить палладий в виде аминохлорида палладия? Медь при этом останется в растворе.

Eftersom vissa personer försöker att uppfinna ett bättre hjul... utan att först ha lärt sig hur ett hjul fungerar.

:mrgreen:

Göran

Ja, det stämmer, innan du uppfinna något nytt - du måste veta hur det fungerar gammal.

 

[Cerber]

I apologize if my translator is not correctly identified your native language.

 

[g_axelsson]

К чему такие сложности?
Не проще ли растворить самородок и восстановить палладий в виде аминохлорида палладия? Медь при этом останется в растворе.

Eftersom vissa personer försöker att uppfinna ett bättre hjul... utan att först ha lärt sig hur ett hjul fungerar.

:mrgreen:

Göran

Ja, det stämmer, innan du uppfinna något nytt - du måste veta hur det fungerar gammal.

That was really good! Just as your English is. I had no problem understanding your second post.

Welcome to the forum!

Göran

 

[Rougemillenial]

What would be a good method for recovering palladium from copper nuggets?

melt into an anode and part with copper sulfate/sulfuric acid solution. The lower the voltage/current the longer it’ll take but the better the separation will be.

 

[Rougemillenial]

I have another question concerning safety.

Is there any potential for evolving any deadly or highly toxic gasses with this method? I am seeing a white mist puff off of the top of the container as bubbles burst on top of the solution.

I am running an exhaust fan and have the door open in the room for a good cross flow, but I am moderately concerned as I do not know they exact composition of the nugget and I do not know what gasses might be able to be evolved by this process.

The gas you speak of is most likely a direct result of using too high a voltage/current. You see, hydrogen formation is a competing reaction at higher voltages via catholic reduction. The white color is just areosolized solution or due to localized boiling. Good question though.