PROCESSING METHOD FOR PLATINUM-GROUP METAL CONCENTRATES BASED ON IRON AND NICKEL FOR PLATINUM-GROUP METAL RECOVERY Russian patent published in 2010 - IPC C22B11/00 C22B3/04 

FIELD: metallurgy.

SUBSTANCE: invention refers to noble metal metallurgy and can be applied in processing technology for platinum-group metal concentrate based on iron and nickel. Processing method for platinum-group metal concentrates on iron and nickel base for platinum-group metal recovery includes concentrate processing with hydrochloric acid with transition of platinum-group metals to solution. Further insoluble sediment is separated, solution is treated with sodium nitrite, and iron hydroxide sediment is removed. Before processing with hydrochloride acid, the concentrate is repulped in water, the pulp is heated, nitric acid is added in amount required for dissolution of about 60% of iron and nickel, and the pulp is heated for 4-5 hours at 85-100°C. Hydrochloric acid processing involves addition of hydrochloric acid in amount required for dissolution of remaining iron, nickel and platinum-group metals and heating for 4-5 hours more at 85-100°C. Phosphoric acid or sodium phosphate is added to the solution before sodium nitrite treatment.

EFFECT: deep recovery of concentrate, prevented formation of explosive air and hydrogen mix and extremely poisonous phosphine gas (PH₃).

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