FIELD: non-ferrous metallurgy. SUBSTANCE: invention relates to non-ferrous metallurgy and can be used in the processing of cakes formed during the extraction of zinc from sulfide concentrates. Zinc cakes are leached with the application of microwave energy at a temperature of 75°C using a solution containing 100 g/l of sulfuric acid in the presence of a reducing agent, as which sodium formiate is used, and sodium chloride with a concentration of 5-20 g/l. EFFECT: method makes it possible to intensify the leaching process. 1 cl, 2 tbl, 1 ex.