Process for the recovery of precious metals from a roaster calcine leach residue

摘要

A process for separating precious metals from a roaster calcine leach residue from a process wherein copper or zinc sulfides are roasted to produce a copper or zinc calcine; the calcine is leached with an aqueous sulfuric acid leaching solution to produce a copper or zinc-containing leaching solution and a roaster calcine leach residue and the copper or zinc-containing leaching solution is separated from the roaster calcine leach residue wherein the process comprises: (a) intimately contacting the roaster calcine leach residue with an aqueous sulfuric acid leach solution containing from about 5 to about 200 grams per liter of sulfuric acid to produce a slurry of leach solution and roaster calcine leach residue and to dissolve precious metal from roaster calcine leach residue; (b) adding copper or zinc sulfide solids to the mixture of leach solution and said roaster calcine each residue; (c) agitating the copper or zinc sulfide solids in intimate contact with the mixture of leach solution and roaster calcine leach residue under oxidizing conditions for a time from about 5 to about 20 minutes to collect precious metal on the copper or zinc sulfide solids; (d) separating the leach solution from the roaster calcine leach residue and the copper or zinc sulfide solids; and, (e) separating the copper or zinc sulfide solids from the roaster calcine leach residue by a froth flotation process.