THERMAL HYDRAULIC METALLURGICAL METHOD FOR PROCESSING OF ELECTRONIC SCRAP ON IRON-NICKEL-COPPER BASE WITH COATING OF PRECIOUS METALS Russian patent published in 2004 - IPC

FIELD: metallurgy, in particular, methods for extracting of precious metals from wastes.

SUBSTANCE: method involves processing electronic scrap having precious metal coating, with base being Fe-Ni-Co alloy; preliminary processing stage involves mixing scrap with potassium chloride and/or sodium chloride and/or magnesium hydrochloride in dry state and holding in muffle furnace at temperature of 500±20⁰C for 55-56 min for producing of cake; washing resultant cake with water and holding in 4.5-5.5%-HCl solution for 20-22 hours; leaching out in 30-35%-HNO₃ solution at temperature of 50-700C; continuously mixing for 0.5-2.0 hours; separating resultant pulp and further separating from pulp precious metal sediment in the form fragments of precious metal layer coating; directing productive solution for processing and separating metals of Fe-Ni-Co base.

EFFECT: improved ecological safety of electronic scrap processing method.

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