OSMIUM POWDER PRODUCTION METHOD Russian patent published in 2001 - IPC

FIELD: precious metals technology. SUBSTANCE: starting osmium-containing material is gradually heated (50 C/24 h) in oxidative medium beginning from 150 C and ending at 500-550 C. Resulting osmium oxides are captured by alkali solutions with concentration 200 g/l. Osmium-containing alkali solutions are electrolyzed to give cathode precipitate. The latter is treated with hydrazine hydrate, washed with water, and reduced in hydrogen medium. Osmium powder obtained is treated with hydrochloric and hydrofluoric acid solutions, washed with water, and dried, the drying operation being combined with additional reduction in hydrogen medium, which is performed at 700-730 C. EFFECT: enabled production of highest-quality osmium powders and increased degree of osmium recovery from starting materials. 5 cl, 2 tbl