Extracting gold from copper
Q. My name is Tommy. I just got a job at a train yard, we move a lot of copper concentrate through our yard which inevitably spills here and there. Someone at work told me that the concentrate (a granular substance) is copper that has just been taken from the mine and has yet to be refined. They also told me that a percentage of it is gold. How would you get the gold out of the concentrate?Tommy A. [last name deleted for privacy by Editor] transportation - Arizona, USA
A. I don't know if we can help you, Tommy, since we deal with metal finishing here rather than refining. But please question your assumptions -- especially when starting a new job! It is NOT inevitable that copper concentrate spills into the ground, and it's probably not acceptable either. Keep stuffing the suggestion box with ideas until the problem is solved.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
A. Dissolve all with aqua regia, then ppt out the copper with NaCl, then filter out the copper chloride and then ppt out the gold as pure with sodium metabisulfite mixed with water. Filter the gold fines and smelt.
You could try dissolution in Nitric acid and that leaves the residue as gold. With excessive Cu, there is a lot of acid gas , brown and irritating so be careful.Dr Malcolm Mudge
- Perth, Western Australia
July 9, 2012
Q. Hi sir. I want to know if aqua regia process is applicable to extract gold from the mixture of nickel and copper? Or what is the best way to separate gold from these metals?anosha and ali
research worker - karachi, pakistan