METHOD FOR COPPER REMOVAL FROM SLUDGES OF SECONDARY COPPER ELECTROLYTIC REFINING Russian patent published in 2024 - IPC C22B15/00 C22B3/14 C22B7/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy of non-ferrous and noble metals, in particular to processing of anode sludges of secondary copper electrolytic refining. Method involves oxidative leaching of sludge without heating with ammonia-ammonium solution at molar ratio of reagents [NH₃⋅H₂O]:[(NH₄)₂SO₄], equal to 3-4 mol/mol, and specific consumption of the sum [NH₃⋅H₂O]+[NH₄⁺] not less than 4.8 mol./mol. Cu with air supply until oxidation-reduction potential in the system is not more than +60±5 mV relative to silver chloride electrode. Ratio of the sludge weight to the volume of the reagent solution – L:S is maintained, which enables to obtain solutions with copper concentration of not more than 0.75 mol./l.

EFFECT: higher resource and energy saving due to exclusion of leaching pulp heating and reduction of specific consumption of reagents for ammonia-ammonium leaching in 2-2,6 times, as well as higher selectivity of copper extraction due to elimination of silver transition to leaching solution of not less than 96%.

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