POSSIBILITIES OF ZINC EXTRACTION FROM GALVANIC SLUDGE BY MEANS OF LEACHING IN SODIUM HYDROXIDE AND FOLLOWING ELECTROLYSIS

The aim of this work is a proposal of innovative technology of metal waste processing - sludge and filtration cakes from galvanizing plants. The paper deals with possibilities of zinc obtaining from waste of galvanic sludge, which arises during galvanic plating. A leaching process in a sodium hydroxide environment was optimized in the laboratory conditions, resulting in separation of zinc from iron and other organic and inorganic components from sludge. The obtained leach was processed by means of the electrolysis in order to get pure zinc. The stainless plate was used as a cathode, nickel plate as an anode. Results of chemical analyses of individual intermediate and final products at the hydrometallurgical processes are presented in this paper.