Refining palladium-contg. crude silver by electrolysis - involves removing palladium from electrolyte with ion-exchange resin contg. chelating anchor gps. and recycling electrolyte.

摘要

Process for refining Pd-contg. crude silver comprises electrolysis in nitric acid electrolyte and sepn. of anodically-dissolved Pd by contacting the circulating electrolyte with an ion-exchange resin contg. chelating anchor gps. (I); the electrolyte is then recycled. (I) is pref. a weakly basic ion exchange resin with tert. amino gps. of formula P-CH-NR1R2 (with P = polymeric matrix; R1 = carboxyl gp. or phosphonic acid gp. and R2 = H, or R1 = R2 = carboxyl gp. or phosphonic acid gp). ADVANTAGE - The invention provides a simple process for the electrolytic purification of crude Ag, in which co-deposition of Pd on the cathode is prevented by removing the Pd from the circulating electrolyte with an ion-exchange resin (I); and the Pd can then be recovered in high yield in a suitable form for further processing.