METHOD OF ELECTROCHEMICAL EXTRACTION OF NOBLE METALS FROM SECONDARY RAW MATERIALS Russian patent published in 2020 - IPC C22B11/06 C22B7/00 

FIELD: electrochemistry.

SUBSTANCE: invention relates to electrochemistry of noble metals, particularly electrochlorination, and can be used in processing secondary platinum group metals (PGM). Method involves treatment of a catalyst in electrochlorination electrolyte with application of direct and alternating currents with preliminary activation of noble metals and their subsequent electrodeposition at the cathode in conditions of reduction of electrolyte volume. Preliminary activation of noble metals in catalyst is carried out in medium of gaseous products of electrolysis with gradual filling of catalyst charge with electrolyte based on hydrochloric acid. After filling with electrolyte – in inert gas at pressure of 5–10 atm. Decrease of electrolyte volume in process is carried out and controlled due to its recondensation into separate accumulating capacity by means of periodic depressurisation of gases into condensation system till moment of accumulation of electrolyte in accumulating capacity. Fresh electrolyte is added to initial volume, pressure of inert gas is increased to initial value of 5–10 atm, and cycle of electrodeposition is repeated with periodic depressurisation.

EFFECT: invention simplifies and increases efficiency of the process while ensuring high percentage extraction of noble metals.

1 cl, 2 ex