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Hartbar

Well-known member
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May 6, 2021
Messages
116
Good day,
I have a lot of gold filled pocket watch plates. I pulled out any steel pins and then hit the plates with a torch to check for tin and lead.
I have scoured the forum for information and links, but I’m a bit confused to be honest.

Any information would be great.
Thank you in advance.
 
The process I should use.
Should I completely dissolve in Aqua Regia?
I’ve read about using nitric acid to just leave shells, then go to Aqua Regia?
I’m just looking for information on how to process from where I’m at.
 
If your asking these questions, then your not ready yet. Especially for stainless gold filled!
Nitric first, then pick out any stainless, then ar.
 
Hi, thank you.
There is no stainless in my gold filled watch plates. I’m not sure what the karat gold is bonded to, bronze, brass maybe, but not stainless.
 
As you may have surmised from the answers thus far, with gold filled, the underlying metal determines the recovery process. This may be why you could not find the answer you were looking for earlier. Palladium is 100% on both his posts. Some may disagree, but this is also how I approach GF items. Time for more coffee.
 
galenrog said:
As you may have surmised from the answers thus far, with gold filled, the underlying metal determines the recovery process. This may be why you could not find the answer you were looking for earlier. Palladium is 100% on both his posts. Some may disagree, but this is also how I approach GF items. Time for more coffee.
Can I assume the underlying metal is some kind of copper alloy, bronze or brass maybe?
I’m honestly looking for some straight up input.
I’ve had my coffee for the day.
 
pocket watch cases are going to be brass, and the method prescribed by palladium will suit you well

but if you file a small groove in one of the pieces and see a silvery metal that doesn't react with nitric, you may have stainless, which i've never really seen on gold filled pocket watch cases.
 
Thanks snowman,
I’ll double check for steel that way, no reaction to magnet though.
So it’s nitric, incinerate, then Ar.
As they say, the devils in the details. Is there a link to details?
 
Iron reacts with a magnet. 400 series Stainless sticks to a magnet.
300 Series Stainless is non magnetic.
 
One straight up answer coming up, this is how I do it.

1. Mechanically remove anything not covered in gold.

2. Cut the GF parts into small bits.

3 Roast/incinerate to carbonize any organic material.

4. Soak in hot nitric acid under a fume hood. Soak until all base metals are dissolved. May take more than one soaking as dissolving base metal will consume the nitric. MUST USE proper fume hood, this step will generate deadly toxic gas!

5. Filter/rinse the left over gold bits.

This completes the "recovery" part of the GF process. Next is to "refine" the GF to higher purity using an AR process.
 
rickbb said:
One straight up answer coming up, this is how I do it.

1. Mechanically remove anything not covered in gold.

2. Cut the GF parts into small bits.

3 Roast/incinerate to carbonize any organic material.

4. Soak in hot nitric acid under a fume hood. Soak until all base metals are dissolved. May take more than one soaking as dissolving base metal will consume the nitric. MUST USE proper fume hood, this step will generate deadly toxic gas!

5. Filter/rinse the left over gold bits.

This completes the "recovery" part of the GF process. Next is to "refine" the GF to higher purity using an AR process.

Thanks Rick,
Straight up works for me.

So from here I would burn again, put in AR, then precipitate with SMB. Rinse, rinse some more, then melt.

I’ve read everything I’ve had time to on GF in forum. The one thing that confuses me is, if you just put the GF in AR, why wouldn’t that dissolve everything, base metal under karat gold and base metal in GF layer?
Then precipitate the gold out with SMB.
Guess it can’t be that simple, I imagine you’d get low karat and poor yield?
 
Garbage In Garbage Out.

If you eliminate as much of the base metals first, when you dissolve the gold and remaining base metals, you'll have a solution with about half gold and half base metals. You'll get a much more reliable and cleaner drop.

If you dissolve everything at once you'll have maybe a few percent gold with a whole LOT of various base metals. You'll have a dirty drop with a lot of drag down, and it's easy to leave values behind.

The first step is recovery. The second step is refining.

Dave
 
What Dave said.

You will use less chemicals and take less time if you fully recover the gold bits from the base/waste materials separately from refining to higher purity.

If you went straight to AR then you'd end up doing it 2 or 3 times as the first drop would be dirty with drag down.
 
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