Patent attributes
The invention relates to a method for recovering gold from a sulphidic concentrate, particularly one containing arsenopyrite and/or pyrite, hydro-metallurgically. The concentrate is first subjected to leaching with a concentrated solution of alkali chloride and copper (II) chloride, by means of which the copper minerals and some of the gold in the concentrate are made to dissolve. Elemental sulphur and precipitated iron and arsenic compounds are separated from the leaching residue using physical separation methods, whereby the first intermediate is obtained, which contains gold-bearing sulphide minerals and gangue minerals as well as the gold that remains undissolved. The free gold that remains undissolved is separated by means of gravity separation methods. After gravity separation, additional comminution is carried out, after which the sulphide minerals are decomposed and the gold-containing solution or residue is routed to the concentrate leaching circuit.
