AP and dissolved gold

[Oz]

I know I have been dissolving a good deal of gold into my AP bath, it sits all too often when life gets busy. What is the best way of removing this gold in solution?

As I build up copper in solution with AP is there a good way to remove some of it w/o destroying the bath?


Ps; If it makes a difference I am aerating it to regenerate.

 

[Andrew W]

I'm not really in a place to give advice, but from what I've read, you should use SMB or some other precipitant to drop the gold. Wait for it settle, and then siphon, pour, or filter off the copper solution. Then add the precipitated gold to your batch of foils (or whatever you have) that are going to be dissolved with AR or HCl-CL for further refining.

As far as removing copper, lazersteve has a tutorial about solution disposal in the turorial section; although, I'm not sure that you'll be able to use the solution afterwards...

 

[Rag and Bone]

Once the items in the AP are stripped, add more scrap. Base metals go into solution and the gold powder gets pushed out. The time to be concerned about the gold in solution is when the AP is tapped out and your getting ready to discard it.

 

[Oz]

Rag and Bone,

I have added several lots of scrap to this solution and have a fair amount of black gold dust on the bottom. If I wanted to collect all the gold that is in solution I could filter out foils and black powdered gold then keep putting copper in my bath until no more black gold precipitates. Right?

After this is where my questions really begin. Can I test this solution with stannous to be sure I have removed all the gold (assuming I have the solution properly filtered)? Just checking.

If there is a way to remove some of the base metals (mainly copper) from this solution then I would never have to be sure I have removed all the gold, I could keep using the solution. I know this part is probably a pipe dream but the question not asked……

If I can’t remove base metals I will filter out all gold then evaporate off the remaining solution until the chlorides and water are gone leaving me with a mixed base metal powder for waste. Any inputs on the toxicity of this powdered waste would be helpful as well.

Hopefully this clarifies my questions a bit.