METHOD FOR UTILIZATION OF CAKES OF TREATMENT PRODUCTS OF FLUSHING WATERS OF ELECTROPLATING SHOPS Russian patent published in 1997 - IPC

FIELD: hydrometallurgy of heavy nonferrous metals. SUBSTANCE: method includes treatment of cakes with sulfuric acid up to pH of acid values, separation of solid phase from solution containing iron (III), copper (II), nickel (II) and zinc (II), selective separation from solution of sediments of ferric and chromic hydroxides, precipitation of basic carbonates of nickel (II) and zinc (II), and dissolving in sulfuric acid, and separation of zinc and nickel from the obtained solution by its electrolysis. Prior to separation of chromic hydroxide, copper (II) is removed by carburizing conducted by zinc-nickel cathode alloy produced at the stage of electrolysis with current density of 300-400 A/sq.m, temperature of 25-35 C and pH 2.5-5.0. EFFECT: higher efficiency. 2 cl, 3 tbl