METHOD OF RECOVERING OSMIUM FOR ION-EXCHANGE RESIN Russian patent published in 1999 - IPC

FIELD: hydrometallurgy of nonferrous and precious metals. SUBSTANCE: osmium- containing ion-exchange resin is treated with reactive mixture containing sulfuric acid and at least one heavy metal hydroxide capable of being dissolved in acid with release of atomic oxygen at redox potential at least 0.85 V against saturated silver chloride electrode and acid-to-hydroxide ratio higher than 1 to attain final concentration of sulfuric acid 20 to 300 g/l. Osmium tetraoxide formed in oxidation reaction is caught from gas phase with alkali solution. Hydrothermal treatment is carried out at 80-100 V and content of resin in slurry no higher than 200 g/l. As heavy metal hydroxide or hydroxide mixture added in amount 0.5 to 1.5 weight parts per 1 weight part of resin, cobalt(III) hydroxide or its mixture with high oxidation-number manganese or nickel hydroxide is used including products of hydrolytic purification of nickel solutions from cobalt and cobalt solutions from manganese, and also products from exhausted solutions after distillation of osmium. EFFECT: increased osmium recovery (to 83-97%) and enabled regeneration of oxidant. 5 cl, 1 tbl, 10 ex