Gold Refining

Hope this helps. Please be very careful.

http://www.roughneckchronicles.com/...inegold.html

There are a few chemist collectors here, and I hope they would chime in.
Not a chemist myself, but since I come from a family of chemists...I'll just say this is not a procedure to try at home.
Cyanide compounds are very dangerous if containment is not 100%--and you might not detect contamination in time. A much better idea to hand this off to an industrial reclaimer for a percentage.

There is a company that sells a pretty safe solution for both refining and recovery. I won't vouch outright for it because I ended up doing some tweaking to suit myself, but they will help and support you with their stuff so after sales service is there. Shor International. They also sell crucibles and stuff, I buy there once a year.

Alchemy at its finest!

great question in OP !
but I'm very, very glad that I have read all of the responses.
I don't know the law where Nancy resides, but where I am, there are several goldmines. The chemicals used to extract gold from the ore can also be used in the manufacture of illicit drugs. So, they are now regulated, as "precursors", under the Drugs legislation. The miners have to be licenced to use the chemicals, and their purchases are regularly audited.
I only mention this in case similar legislation operates elsewhere.

@Ed What's with the record keeping on the ethanol? Just taxation issues? And by pure you mean "as possible" before breaking the azeotrope? Or you received it in vacuum? It's a small nuisance to dry, but having Dewars lying around makes me look too geeky :D

Yes, it was just a tax thing. The ethanol we bought was for some very specific and sensitive testing that was not compatible with the usual ethanol denaturants. The BATF / US Treasury (probably along with the FDA) regulates and taxes drinking ethanol to a considerable degree. Ethanol used for scientific purposes is not taxed at all unless sold in a sales tax jurisdiction. We still had to justify the purchases and track the amounts used on a form that we made up. It included the test, date, amount used, approximate amount remaining in the bottle, and the initials of the dispensing chemist and the technician who actually performed the tests. This form had to be available for unannounced examination at any time. It was then mailed in annually but we also kept copies for our files.

Yes, this ethanol was VERY pure. It was triple distilled via the usual azeotropic distillations, chemically dried over molecular sieve, and then packaged under dry nitrogen gas. The seal on those bottles was air-tight, so we used syringes to remove the ethanol from the bottles. It was then injected into the test solution, also under N2 gas. Additional N2 was added to the bottle from time to time to equalize the pressure as the liquid was withdrawn.

Yes, Dewars and other scientific apparatus can look pretty cool but there is the "geek factor" to consider.