PLATINUM METAL ISOLATION PROCEDURE Russian patent published in 1998 - IPC

FIELD: chemistry and nonferrous metallurgy. SUBSTANCE: invention can be used in production of high- purity silver and platinum metals. Initial silver-containing material with platinum metal admixtures is chemically or electrolytically dissolved in nitric acid with concentration 150-200 g/l. From the solution obtained, platinum metals are sorbed on anionite based on vinylpyridine and divinylbenzene copolymers. Desorption of platinum metals is performed with agency of 3-8 M ammonia solution and platinum metals are then isolated from extract solution by one of known techniques: electrolysis, precipitation of individual complex salts, and isolation of insoluble compounds. Method gives rise to 100-fold increase in the degree of separation of platinum metals from copper and silver. Platinum and palladium-containing eluate is virtually copper and silver-free. High-purity silver is also obtained from materials containing platinum metals and copper. EFFECT: considerably increased metal separation degree. 3 tbl