METHOD OF PRODUCTION OF METALLIC PALLADIUM Russian patent published in 2003 - IPC

FIELD: production of pure metallic palladium of respective chemical form. SUBSTANCE: palladium-containing material is treated with aqua regia solution, palladium settles in form of chloropalladate salt due to treatment of aqua regia solution by ammonium chloride; pulp thus obtained is settled, cooled and filtered; sediment on filter is treated with ammonium chloride solution. Chloropalladate salt is settled by solid ammonium chloride and sediment on filter is treated by saturated ammonium hydrochloride; then sediment thus treated is dissolved in water and solution thus obtained is filtered, neutralized and palladium is reduced to metal by hydrazine hydrochloride at pH≥2 or formic acid at pH≥6. Metallic palladium is filtered, washed and dried at temperature of 90-100 C. Proposed method makes it possible to separate palladium in form of pure metal of respective chemical form at minimum losses at all stages ensuring separation of 96% of palladium-104 at degree of purification of 99.996% and 70% of natural palladium from wastes of isotopic process at degree of purification of 99.5% and 93% of natural palladium from waste aluminopalladium catalyst at degree of purification of 99.5%. EFFECT: enhanced efficiency; reduced power requirements. 3 cl, 7 ex