a big failure-what happened?

[arthur kierski]

i shredded 300lbs of motherboards and separated the metals from the plastics and fiberglass by what here is called eletrostatic separation(separates conductive material from non conductive)--------The metals left became 68lbs(beautifull copper colour tailings with some plastics left(10%)) here my drama began:first tried nitric to eliminate copper and base metals--result it eliminated the copper but took 2days to filtrate because of tin and lead complex(metastanic complex)---the material left from the copper leach was refined with ar and no gold--- i repeated various methods of extraction like ac ,ar, ap,and finally cyanide leaching----NO GOLD(very frustating) ---i did these experiments for 8 days with no results----so i still have 55lbs of this copper tailings and need help to try (if exist---which i doubt) to get the gold-----what i thought was a great idea to obtain gold from motherboards ,turned to be a big flop

 

[Platdigger]

?

 

[SapunovDmitry]

Motherboards usually have 70-120 gramms per ton and copper content of 10-25%. So if you had 300 lbs (~150 kg) of motherboards you had about 10-15 gramms of gold in them. If you got 68 lbs (~30 kg) of copper from it and had no losses you are lucky to still have your 10-15 gramms (in fact expect at least ~10-15% losses cause a lot of gold is in plasic flatpacks). 68-55 makes 13 lbs (~6 kg) of analysed material (max 2 gramms can be in this materal).U've used 6 methods so in average u had 0,3 gramms of gold in each (~1 kg) sample. Are u sure that you are able to pull such a small amount of gold out of your copper and to recognize it? Try using lab analysis for your gold bearing copper. (I thnk it will certainly show you some gold ).
BTW great work though. )))

 

[Oz]

Arthur,

I would also check the crud left in your filter after nitric digestion. The goo of nitric and tin can easily grab fine particles of gold. Try incinerating this portion then HCl to see if some of your gold is there.

 

[arthur kierski]

oz,i did what you sugested and no gold was found-----i also did a batch with hcl(32%) to try to eliminate some tin and a violent reaction happened---i deduced that it was aluminium(of course some iron)----could aluminium create dificulties to obtain gold? i cannot send a pm in this new forum

 

[goldsilverpro]

Al can be a huge problem. Both Fe and Al should be removed before using any of these acids. When using nitric, the Al and Fe would cement out the Cu that you have dissolved. With AR, everything dissolved will cement onto the Al. Similar cementation would occur with AC, AP, or cyanide. In any case, I would expect a big voluminous mess of solids. It's hard to find a little bit of gold in a big mess. Can you see any metallic gold anywhere after the nitric?

 

[arthur kierski]

gsp; thanks to clarify me about the al and fe cementations with almost all leachers---ar,ap, ac, and cianides----i think that that might be the problem that i am finding---tomorrow i will make one or 2 batches eliminating previously al and fe ---the results i will put in this thread for further studies .i think that if the idea works,it will help all members of our forum