METHOD OF EXTRACTING CADMIUM FROM FLUSH WATER CONTAINING CYANIDES Russian patent published in 2020 - IPC C25C1/16 C02F1/461 C02F103/16 

FIELD: technological processes.

SUBSTANCE: invention relates to electroplating, in particular to methods of electrochemical extraction of cadmium present in washing water in form of cyanide complexes, and can be used for removal of cadmium ions from washing water of trapping baths in the cadmium section in order to prevent their ingress into waste water of the electroplating shop. Extraction of cadmium is carried out by electrochemical treatment of flushing water in electrolysis cell with cation-exchange membrane and electrodes from carbon steel. During electrolysis solution from cathode chamber circulates through anode chamber. Electrolysis is carried out in 0.5–1 A·h passing mode of electricity, through 1 l of circulating water per 1 g of sodium cyanide contained therein.

EFFECT: method enables to prevent formation of insoluble cadmium compounds and hydrogen cyanide vapors during electrolysis.

1 cl, 1 dwg, 3 ex