PROCESS OF RECOVERY OF NOBLE METALS FROM WASTE AND ARTICLES OF ELECTRON AND ELECTRICAL ENGINEERING INDUSTRIES CARRYING NOBLE METALS IN COATS Russian patent published in 1999 - IPC

FIELD: hydrometallurgy. SUBSTANCE: invention can be used also for recovery of noble metals from waste of watch and jewelry industries. Proposed process is based on established facts that selectivity is maintained till solutions saturated with salts of noble metals ( 50.0-100.0 gram of noble metal per one liter ) are obtained even in presence of crystals of salts of noble metals at low temperatures of 18-5- C in presence of inhibitors and at higher temperatures of 50-120 C under action of alternating current of 20-100 Hz with content of less than 5.5 per cent by weight of them in aqueous solution. For more complete recovery of noble metals portion of starting raw material treated in solution saturated with salts of noble metals can be sent for another treatment in new solution. As result of processing of starting materials in agreement with proposed process chemical agents are used for dissolution of noble metals only at stage of their wash-out. Wastes of process are easily utilized non-ferrous metals and sulfuric acid extracted from pickling solution together with noble metals can be completely regenerated in process of extraction of noble metals from salts and can be returned to process after concentration. Complete cycling of all solutions carrying noble metals excludes possibility of their loss. EFFECT: enhanced efficiency of process.