Non-Chemical Another purification step prior to AR

[Paige]

I found that if you treat karat jewelry as you would pins, then just boil them in HCL, you remove copper from the jewellry.

Your HCL takes on the copper green color and the gold jewellry gets "yellower". It also gets brittle and chins can be pulled apart, so I know this isn't a surface phenominon.

There is no gold in the residual HCL, but it is removing the copper.

What is that about trash in = trash out. If you remove much of teh copper in a HCL wash or two, before going to AR, then there is less copper to remove.

I know this flies in the face of those of you who believe in inquartation.

Paige

 

[goldsilverpro]

Very interesting. This just goes to show that one never knows it all. I wonder what happens with the silver? It would appear that, with no nitric used, there is no silver chloride produced.

What karat (and color) gold did you try this on? Have you tested the solution for gold, with stannous chloride?

Keep us informed on this. It could be a big thing.

I don't think that the word "believe" should apply to inquartation. It's only another way to do things. There's a whole world of new things to learn in this business and imagination and experimentation will reveal them. Good job!

 

[Harold_V]

I know this flies in the face of those of you who believe in inquartation.

Paige

Try your new "invention" on a heavy 18K green gold piece, then get back to me. For that matter, try it on a heavy 14K green gold piece.

You're spinning your wheels trying to invent something that has been well researched and proven. Unlike GSP, I don't see the point. Inquartation is used because it works. Always.

In most cases, HCL will not--------- unless the material is very thin. It's protected from the acid by the gold in the alloy. You'd also create problems with the remaining silver when you attempted to digest the gold with AR.

If you insist on processing karat gold without inquartation, you'd be far better served to use nitric instead of HCL---it also dissolves the silver-----at least until the gold shields it from the acid.

Does it really matter if the gold you precipitate comes down 993 instead of 992? Isn't the objective a minimum 9995? Your chance of achieving that target is best when you eliminate the base metals, not just reduce them partially, even if you can get your idea to work some of the time.

Harold

 

[Paige]

It has been on 14kt. The last HCL bath produced some yellow liquid. I will be interested to test the gold for purity.

It's allo going into AR. Then following Harold's steps toward purity. I might try an electronic refining in there.

A professional tested my last batch with atomic absorbtion I think. He found it to be .99686.

Not really good enough.

Paige

 

[goldsilverpro]

Did you pay for this assay? If so, I think you wasted your money. I don't think you can rely on atomic absorption results. There are two types. One where a solid sample is vaporized in a furnace and the other where the sampled is dissolved. The latter is probably not accurate within 1% unless long drawn out expensive methods are used - solvent extraction, method of additions, etc. The furnace type is a little more accurate but only in the hands of an expert.

The most accurate direct method in existence is fire assay. About 5 times more accurate than the AA under the best circumstances. Here's a good article on the subject:
http://www.gold.org/discover/sci_indu/GTech/2001_32/WOR82071.PDF

 

[Paige]

Nothin'