Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ
The authoritative public forum
for Metal Finishing since 1989
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Refining of scrap gold
Q. I have 4 pounds of scrap gold. I want to learn how to refine it. Any suggestions? Will appreciate your reply.
Santiago MaldonadoMaldos - Agua Prieta Sonora, Mexico
2002
1. Make up solution => HCl:HNO3 = 3:1
2. Make gold to small pieces (about 0.5cm)
3. Put small gold pieces into the solution.
4. Boiling (until dissolve out)
5. Boiling continuously...(For NOx out)
6. Add HCl 2~3 times ( HNO3 will disappear and the solution will be almost HCl).
7. Add Urea for elimination of the remaining small amount of NOx. Bubbles will be generated (until no bubbles).
8. Cooling the reactor until 80-90 °C. then Add Sodium sulphite---> you can see the yellow gold powder.
9. Filtering with warm pure water until pH.
10. Burning them including filter paper at 1000 °C.
11. Melting them with O2 torch. You can get 99.9% up pure gold.
- KOREA(south)
Q. Hi,
I am in search of a gold refining procedure other than using nitric acid and muriatic acid
⇦this on
eBay or
Amazon [affil links] . Does anyone know of such a procedure? Also a vendor offers a simple gold refining machinery which uses this principle. It uses a certain type of salt water bath using electric current. Does any one knows which type of salt they are using. Please give whatever help you can. Thank you very much.
Regards,
- Mumbai, India
2002
A. GC Salt is one name I came across.
Tom Eames- San Jose, California, USA
2005
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