PROCEDURE FOR EXTRACTION OF GOLD FROM REFRACTORY GOLD CONTAINING ORE Russian patent published in 2011 - IPC C22B11/08 C22B3/18 

FIELD: metallurgy.

SUBSTANCE: procedure consists in concentration of ore with production of flotation gold containing concentrates, in bio-oxidation with production of ferric iron in liquid phase, in separation of solid phase from liquid phase and in production of bio-cakes, in their sorptive cyanidation, in gold desorption, in its electrolytic extraction and in successive melting into ingots of dore alloy. Prior to bio-oxidation there is performed oxidation of flotation gold containing concentrates with solution of ferric iron produced at production of bio-cakes with filtration; successively, solid phase is separated from liquid phase. Separated solid phase is subjected to bio-oxidation and it is performed at pH 1.5-1.8 and contents of solid phase 15-20 % and at such intensity of aeration-mixing, which is characterised with volume coefficient of weight transfer for oxygen 200-800 h^-1 to oxidation of sulphide minerals and ions of ferrous iron in gold-containing concentrate.

EFFECT: intensified process of bio-oxidation of sulphide concentrates containing refractory gold and increased efficiency of extracting gold with cyanidation.

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