METHOD FOR SELECTIVE EXTRACTION OF NOBLE METALS FROM GOLD-BEARING CEMENTATE Russian patent published in 2022 - IPC C22B11/00 C22B7/00 C22B3/06 C22B1/04 

FIELD: metallurgy.

SUBSTANCE: invention relates to the metallurgy of precious metals and can be used for the selective separation and concentration of gold, silver, platinum, palladium and rhodium from gold production cementate. Cementate is heated in air by heating at a temperature of 700-800°C, after which noble metals are sequentially leached in reagent solutions from the resulting cinder. It is leached with a solution containing, vol.%: 85-95 hydrochloric acid and 5-15 nitric acid, at a ratio L/S=3-5, followed by separation of gold from the solution, and then a concentrate of platinum group metals containing platinum and palladium. In this case, rhodium is concentrated in the insoluble leaching residue. Silver is leached from said residue with a solution of sodium sulfite at a L/S ratio of 15-22, followed by separation of silver from the solution, while selenium transferred to the gas phase is withdrawn.

EFFECT: method provides selective isolation of silver and rhodium as individual products from the composition of the collective concentrate of precious metals, as well as an increase in the degree of extraction of metals into leaching solutions.

2 cl, 1 tbl