METHOD FOR PRODUCING SILVER AND PLATINUM GROUP METALS Russian patent published in 2019 - IPC C22B11/00 C22B7/00 C22B3/24 C25C1/20 

FIELD: technological processes.

SUBSTANCE: invention concerns the production of silver and the isolation of a platinum-group metal concentrate during the refining of an alloy of precious metals (Dore alloy) obtained by processing copper-electrolyte slimes. Method involves dissolving the starting alloy in nitric acid in the presence of ammonium ions, separating the precipitate and cleaning it from a number of impurities, two-stage purification of silver-containing solution: sorption on anion exchange resin and hydrolytic ammonium hydroxide. After separation of the precipitate, silver is electrolytically separated with electrolyte recovered to dissolve the alloy, desorption of platinum and palladium from the saturated anion exchanger, followed by electroextraction of the platinum metals.

EFFECT: this method allows one-stage production of high purity cathode silver, direct silver recovery, elimination of liquid waste and anodic electrolysis residues, and processing of silver alloys with a silver content of less than 95 % on an industrial scale.

1 cl, 4 tbl