简介 |
A method for concentrating precious metals contained in the leaching residue discharged om a copper hydrometallurgical process by removing pyrite om the residue. A method for concentrating precious metals in the leaching residue containing pyrite, elementary sulfur, precious metals and gangue, discharged from a copper hydrometallurgical process which comprises steps of leaching in an acidic, aqueous solution, reducing the copper-containing leaching liquor and electrolysis for copper recovery to treat copper sulfide ores, comprising (1) pyrolysis step in which the leaching residue is thermally treated at 550°C or higher in a non-oxidative atmosphere, to produce the calcined ore containing pyrrhotite, precious metals and gangue, and (2) a re-leaching step in which the calcined ore is re-leached in an acidic, aqueous solution, to be separated into the re-leaching residue and iron-leached liquor, the former containing elementary sulfur, precious metals and gangue. |