METHOD OF LEACHING AND EXTRACTION OF GOLD AND SILVER FROM PYRITE CINDER Russian patent published in 2020 - IPC C22B7/00 C22B11/00 C22B3/16 

FIELD: technological processes; mining.

SUBSTANCE: group of inventions relates to processing of gold-bearing and silver-bearing wastes of ore-dressing plants. Pyrite refuses are processed by agitation leaching of pyrite cinder with extraction of gold and silver. At cascade of wet grinding mills super-fine grinding of pyrite cinder to fraction of 5–8 mcm is carried out, then in form of water-containing pulp they are supplied to reactors for agitation leaching with mixing by means of double hydrodynamic impellers. Leaching of pulp is carried out at supersonic speed with solution of thiourea with concentration of 0.1 % with sulfuric acid with concentration of 0.5 %. Sludge formed after leaching is washed from productive solution and in form of wet cake is supplied to vacuum ceramic filter for dehydration. Dehydrated cake is used for cement production. Productive solution containing gold and silver is subjected to electrolysis for extraction of gold and silver, after which the productive solution is returned into the production cycle into the water-containing pulp.

EFFECT: inventions enable to carry out environmentally safe fast efficient leaching and extraction of gold and silver from pyrite cinder.

6 cl, 8 dwg, 3 tbl