Reducing copper from the auric acid.

GregerG · Nov 28, 2011

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 · Nov 28, 2011

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 · Nov 28, 2011

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 · Nov 29, 2011

GregerG said:
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 · Dec 1, 2011

Dear GregerG

GregerG · Dec 4, 2011

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