METHOD OF SEPARATION OF METALLIC PALLADIUM FROM WASTE MANGANI-PALLADIUM CATALYST Russian patent published in 2005 - IPC

FIELD: separation of palladium from waste mangani-palladium catalyst and cleaning of palladium.

SUBSTANCE: palladium-containing concentrate is treated with aqua regia solution and palladium is deposited in form of chloropalladate by means of treatment with aqua regia solution with solid ammonium chloride, pulp thus obtained is settled, cooled and filtered; sediment is treated with saturated hydrochloric acid solution of ammonium chloride. Then sediment thus treated is dissolved in water and solution is filtered and neutralized; pallarium is restored to metal by means of hydrochloric acid hydrazine at pH≥2 or formic acid solution at pH≥6; solution is filtered and metallic palladium is washed and dried at 90-100°C. Prior to treatment, mangani-palladium catalyst with aqua regia, it is dissolved in concentrated hydrochloric acid; solution is neutralized by asmmonia to pH=6-7 and treated with formic acid at flow rate no less than 1 l of HCOOH per kg of mangani-palladium catalyst; then mangani-palladium concentrate is filtered, washed and dried at 90-100ºC.

EFFECT: enhanced purity of metallic palladium at minimum losses of catalyst at all stages of chemical treatment.

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