METHOD FOR REGENERATION OF FREE CYANIDE FROM SOLUTIONS WITH SEPARATION OF FORMED SEDIMENT Russian patent published in 2018 - IPC C01C3/02 C02F1/62 C02F11/14 C02F101/18 C02F101/20 C02F103/16 

FIELD: metallurgy.

SUBSTANCE: invention can be used in non-ferrous metallurgy, gold mining, galvanic production. Method for recovering free cyanide from process solutions, containing cyanides and heavy metals, includes reagent treatment of solutions in acidic medium with sulfide ion, or hydrosulfide ion, or mineral acid. Metal-containing precipitates are filtered, then the clarified filtrate solution is subjected to alkaline treatment to obtain a solution containing free cyanide. Metal-containing precipitates, formed during the reagent treatment in an acidic medium, are thickened. Above thickened product is subjected to an alkaline treatment at pH 8–12 and filtered. Resulting alkaline filtrate is mixed with the starting solution or sent to thicken.

EFFECT: invention makes it possible to ensure safe removal of formed sediments, to reduce the filtration area while maintaining high cyanide regeneration rates.

1 cl, 3 dwg, 1 ex, 2 tbl