A refiner to extract gold from melting dishes

[Lobby]

Actually, not your typical "boraxed" melting dishes, but a really fouled one.

Longish story:

A scrap buyer competitor came by today and asked if I'd help him melt some scrap. Then analyze with my XRF. Of course I said yes. 1st batch (14k sorted) went fine. 2nd batch (18k supposedly) went horribly.

Obviously one / some of the pieces weren't gold and when I attempted melting with an oxy/propane torch, the non-gold metal oxidized and formed a thick, heavy slag on the dish. Those of you who've read Hoke's "analyzing precious metals" know that metals like copper, etc burn instead of melt in a strongly oxidizing flame.

Well, there's a layer of gold in the bottom of the dish. Slag all over the top. And a mess overall.

I suppose I could chop off a piece of the slag, XRF it, and if copper, dissolve it all away with nitric acid. But I don't wanna.

Instead I'd like to find a refinery who'd want to do this. Anybody interested?


:?:

 

[Pantherlikher]

I don't wanna either.

 

[Pantherlikher]

Sorry for the comment. It sounded just like 1 of the kids here making mistake and refusing to fix it. Was humorous.
I don't exactly know how the testers work but guessing they scan and read what they see. So why not drill a hole through each piece or file alot and examine well before melting?. Avoid future problems.
You mentioned a compediter. Have you explained the situation and gotten the go ahead on your intended fix? No matter what, you need to "save face" and make it known you don't wanna fix it in house and are looking for someone to do it. Honesty fixes everything even if you don't like the outcome.

Can't you simply remelt and pour it into water to shot it and test it that way to determin what's what before spending money getting someone else to do it?
Simple unfully educated question by the by.
BS.
Still looking for answers on the questions the voices ask me.

 

[Lobby]

No problem.

Making a bunch of ash when one melts certain non-precious metals with a oxy torch is a known issue. Hoke describes it as a method to differentiate between these non-precious metals and gold.

I don't particularly care to investigate the chemistry of removing those ashes from the pm's.

All I want to find is a refiner who does this stuff. Seems to me a full service refiner who is used to doing sweeps, incineration, etc might be interested...

 

[Palladium]

Is it just this one dish?
How much gold do you think is in it?

 

[nickvc]

Have you tried heavily fluxing the mess,remelting and pouring the gold into a heated mould. The dish sounds like its ruined anyway so its not going to be reusable, offer the slag to your customer and if he doesn't want it put it into your rainy day pile for later processing by either yourself or another refiner, the same applies to your dish save until you have enough low grade to process.

 

[glondor]

Put the dish in a pan of sulfuric/water on heat for a while, let it sit for a week, the slag will all wash away and the metal will remain as powder.

 

[Lobby]

Is it just this one dish?
How much gold do you think is in it?

It was two chains of supposedly 18k gold. One was clearly fishy looking (yellow colored aluminum and very light), but I didn't want to embarrass they guy by appraising his gold right in front of him.

Instead I ruined his other, presumably good gold necklace, and ruined my melting dish. :roll:

:mrgreen:

Just pulling a weight out of the air, I'd guess the ash might contain up to about 1/2 oz gold.

 

[Lobby]

Have you tried heavily fluxing the mess,remelting and pouring the gold into a heated mould. The dish sounds like its ruined anyway so its not going to be reusable, offer the slag to your customer and if he doesn't want it put it into your rainy day pile for later processing by either yourself or another refiner, the same applies to your dish save until you have enough low grade to process.

I put about 5 tablespoons of anhydrous borax into the dish as soon as I saw it fusing. Didn't seem to make a difference.

The guy is supposed to come by my shop, where I can presumably analyze the ash with my XRF. Let's see.....

 

[Lobby]

Put the dish in a pan of sulfuric/water on heat for a while, let it sit for a week, the slag will all wash away and the metal will remain as powder.

If I can't find a refiner who will mess with it, I may offer to treat it for him.

Why sulfuric instead of HNO3? I have both, but the first thought that came to mind with 50:50 HNO3: water...

 

[Palladium]

If you want to send it to me i will run it for you. Pm me.

 

[glondor]

Sulfuric will eat all the slag and glass.