Electrochemistry separating gold from brass & nickel

[shabtai]

I have access to scrap which consists of brass with a thin coating of nickel, and on the nickel is a thin coating of gold. What is the best way to separate only the gold from both the nickel and the brass using electrolysis?

 

[butcher]

The answer is simple study the forum.
Doing so can answer most any question you can think of, and many you have not thought of, or wouldn't even think to ask.

Concentrated sulfuric acid gold stripping cell.

 

[goldsilverpro]

To strip gold from the nickel/brass, you basically have 2 good choices, the electrolytic concentrated sulfuric acid stripper or the cyanide stripper. You might also use the iodine/iodide stripper but it's more complex and more expensive.

You could also choose to dissolve the nickel/brass away from the gold. You could do this in nitric acid or a hydrochloric acid/hydrogen peroxide mixture, called AP on the forum. You could probably also do this with a heated mixture of weak sulfuric + peroxide.

In both cases, you would finally dissolve the gold in aqua regia or HCl/bleach to purifyit.

You could dissolve everything in aqua regia but you would then likely have problems getting the gold.

For details, you need to search. It's all on the forum.