Reducing copper from the auric acid.

[GregerG]

I have this scrap gold that is gold and copper layer on layer so removing the copper before dissolving it in AR is not possible.
This makes for a highly copper polluted auric acid.

The question is - will SMB drop only the gold - or will the dropping be copper polluted?
Is there a way to drop the copper before dropping the gold?

Or is the best way to drop it with SMB and then re-purify it with nitric acid, then re-dissolving it in AR?

Cheers!

 

[Oz]

What is the percentage of gold out of your multiple layers?

Melting as an inquartation may be your best path depending on the gold/copper ratio and possible other contaminates.

 

[Geo]

if you dissolve as is with the base metal you can drop the gold with SMB but it will be dirty and will need to be redissolved to purify.i would like to recommend that instead of AR for the second dissolution that you instead use hcl/cl as it is less expensive and it works really well on powders and foils.remember that gold dropped from solution that contain base metals you will always have "dragdown" that's where base metals are dragged down with the gold out of solution when precipitated.these can usually be left behind with the following washes and rinses and a second dissolution followed with washes and rinses.

 

[Harold_V]

I have this scrap gold that is gold and copper layer on layer so removing the copper before dissolving it in AR is not possible.

Are you speaking from experience, or speculating? If you haven't tried a diluted nitric digest, I suggest you do so. Do it in a covered vessel (beaker with a watch glass) and apply heat, keeping the temp near boiling. I expect you'll seriously eliminate much of the copper, if not all. It's worth a try.

Harold

 

[Lino1406]

Dear GregerG

 

[GregerG]

From experience yes.
So I just had to try it, and it actually works great.
Sure the solution turned blue-green, but with SMB normally onlt Au dropp (melted and tested a piece) but I'm gonna re-dissolve it just to be on the safe side.

My goal isn't to purify it as much as humanally possible, only 999 so I can sell (t0 pay of some debts)... if it worent for this I'd have $115k 'laying aroung'

If anyone know where here in Sweden where to sell this amount any suggest is well recommendend, most pay-by-cash sites only pay 60 to 70% of the 'real' gold value.
I need a person I can TRUST since alot of my life hang on that what I get out of this.
Is 80% (cash and no questions asked a good deal=

//Greg

 

[Geo]

there are alot of reputable refiners here on the forum that can give you a better % than that. just ask around as im sure you will find someone.