anoop.motghare - 12-7-2017 at 03:34
I am doing research on gold recovery from e waste. I have extracted gold from gold finger nails using acetic acid, Hcl and oxidant. I got very good
result & all gold dissolved in solution. My main concern is about form of gold in solution whether it is gold acetate or chloroauric acid. My
second concern is how to extract gold from my final solution, I used sodium meta bisulphite to extract gold from final solution but solution turned
yellowish from green color but no gold lumps observed. Solution observed is yellow in color with white powder precipitate might be smb. Kindly help
me for how to extract gold from that solution or which chemical is required.
j_sum1 - 12-7-2017 at 03:38
You need to search for threads by kadriver. He has a youtube handle "sreetips".
He developed a novel method for gold extraction using acetic acid and salt. It was posted here and discussed in length.
Tellurium - 12-7-2017 at 21:56
If the gold is still present in the form of an acid salt I would try to neutralize most of the acid using Sodium hydroxide/bicarbonate/carbonate and
then displace the gold in solution using zinc powder.
The zinc you can filter of and leach it with hydrochloric acid to get rid of residual zinc powder.
If you have still to many unsoluble contaminations, that don't dissolve in acid I would try to bring the gold back in solution using aqua regia and
then precipitating it using SO2 or the corresponding salt. Another option would be cyanide to dissolve the gold and then using zinc for precipitation
of the gold(I used this process).
Maybe you have enough oxidizer and acid left in the solution, that the gold dissolves back in the solution while precipitating with metabisulfite or
isn't even precipitating. So eventually you should just try to destroy residual oxidzer(did you use H2O2? Then try some Iron(III)-Ions or a bit of
MnO2).
diddi - 12-7-2017 at 22:59
sodium metabisulfite is what I use for pulling out Au at that stage of the ewaste process. then melt with induction coil.
[Edited on 13-7-2017 by diddi]
anoop.motghare - 13-7-2017 at 03:19
Thank you, I will surely check that as per your advice.
anoop.motghare - 14-7-2017 at 01:38
Thank you, I will surely check that as per your advice.
NEMO-Chemistry - 14-7-2017 at 05:35
I think this is the thread, first page or so seems a bit skeptical then it gets really good!
Really worth a read and one my fave threads on here http://www.sciencemadness.org/talk/viewthread.php?tid=63606#...
I think aga christened it the fish and chip process 
[Edited on 14-7-2017 by NEMO-Chemistry]