How to re-refine a near pure gold button?

[bhilton]

Hi all, I have a 3g button from my early learning days of refining. I can tell by looking at it, the colour is not quite right. I was wondering, since it is already melted and in a button, what’s the simplest way to refine again?

Can I heat it and hammer it as thin as I can get it and go straight to aquaregia?

Thank you,
Bill

 

[Yggdrasil]

Hi all, I have a 3g button from my early learning days of refining. I can tell by looking at it, the colour is not quite right. I was wondering, since it is already melted and in a button, what’s the simplest way to refine again?

Can I heat it and hammer it as thin as I can get it and go straight to aquaregia?

Thank you,
Bill

Quickest will be to flatten it as much as possible and then cut it into strips.
Then you twist each strip so it don't lay flat and obstruct other pieces.
Then straight normal AR.

Edited to correct spelling.

 

[bhilton]

Quickest will be to flatten it as much as possibleband then cut it into strips.
Then you twist each strip so it don't lay flat and obstruct other pieces.
Then straight normal AR.

The twisting is a great idea!

Thanks

 

[Shark]

With out those twist it can two to four times longer to dissolve. Well worth the extra effort.

 

[FrugalRefiner]

You could use it to kill excess nitric when you're dissolving gold in AR. It was the technique Harold taught. It doesn't cost you any extra acids, since you're using up the excess from dissolving other material, and it will get your button cleaned up in the process.

Dave

 

[bhilton]

You could use it to kill excess nitric when you're dissolving gold in AR. It was the technique Harold taught. It doesn't cost you any extra acids, since you're using up the excess from dissolving other material, and it will get your button cleaned up in the process.

Dave

Another good idea!

That won’t always work, as I use sulfamic acid crystals to drop lead, and for my 2nd and 3rd refines I usually undershoot nitric and drop partial milliliters to finish.

 

[bhilton]

Out of curiosity, what karat will AR not work, less than 22k?

I believe this button to be 23k plus.

 

[FrugalRefiner]

It's not really a matter of the karat of the gold, it's the silver content that causes problems. Once the silver content reaches around 10%, it will form a crust of silver chloride that will stop the AR from reaching the interior of the gold. If you had an alloy of 50% gold and 50% copper, the AR would dissolve it all.

Dave

 

[bhilton]

Another good idea!

That won’t always work, as I use sulfamic acid crystals to drop lead, and for my 2nd and 3rd refines I usually undershoot nitric and drop partial milliliters to finish.

Ahh right, I knew that concept, but sometimes the brain doesn’t compute the same when coming at things from a new angle. Lol

The 10% I didn’t know. Thanks!

Edit: this was supposed to be a reply to Dave.