Precipitating gold from AR solution

[Anonymous]

Hello, im kind of a noob when it comes to gold refinery so some help would greatly be appreciated. I have removed the gold CPU pins from CPUs via soaking them in hcl for a couple of days. So now i have a bunch of cpu pins, i added an AR solution to the pins and disolved them. This i've done in a couple test batches but now im kind of stuck. I'm not sure how to precipitate the gold from the AR solution. I've read im supposed to neutralize with urea then precipitate the gold with smb. Is this correct? Also if this is correct, what am i looking for as a precipitant? (eg brown powder, white ppt, etc.) Thank you very much.

-Bojangles

 

[butcher]

evaporation technique works better for me than urea to rid nitric acid from solution, SMB or ferrous sulfate, will precipitate the gold as long as nitric eliminated properly, you should have brown precipitant, the solution should clear,if your solution now is yellow it will be fairly pure, if your solution is green you still have copper in your solution, this can determine how pure your gold will be from this first refining,of this lot of gold, also you will need to learn good washing technique for your powder, all of this has been discussed several times.have you been studying the forum? it will answer your questions, look for Hokes book, you will learn so much from doing this, and avoid costly mistakes.