PROCEDURE FOR BACTERIAL OXIDATION OF SULPHIDE GOLD BEARING CONCENTRATES Russian patent published in 2011 - IPC C22B11/00 C22B3/18 

FIELD: metallurgy.

SUBSTANCE: procedure consists in supply of concentrate of salts in their composition containing nitrogen, phosphorus and potassium, nutrient for micro-organisms, into bio-pulp. Also, bacterial oxidation is carried out in two stages. At the first stage nitrogen and 50 % of phosphorus are fed in form of urea and orthophosphoric acid to oxidation of 80-85 % of pirrotin and arseno-pyrite. The rest amount of phosphorus and all amount of potassium is supplied at the second stage in form of twice-substituted potassium phosphate and potassium sulphate at amount required for transition of (15.2÷15.6) % of antimony from concentrate to a liquid phase of bio-pulp in form of antimony potassium sulphate (III).

EFFECT: raised degree of oxidation of sulphide sulphur and antimonite; reduced content of elementary sulphur in bio-cake and accelerated rate of sulphide bio-oxidation.

1 dwg, 2 tbl, 1 ex