METHOD FOR DECONTAMINATION OF WASTE WATER OF GOLD-MINING FACTORY Russian patent published in 2019 - IPC C02F1/00 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of purifying waste water containing simple and complex cyanides, rhodanides, as well as arsenic and non-ferrous metals and can be used for decontaminating the liquid phase of tails of cyanide leaching of noble metals from ores, concentrates and man-made wastes. Object of the invention is to purify cyano-containing waste water from gold recovery factories from cyanide and rhodanide ions with achievement of their concentrations, meeting requirements for recycled water and water discharged to tailing dump of gold recovery factories, as well as reduced concentration of arsenic, copper and nickel due to the possibility of monitoring and controlling pH during the entire decontamination process. Task is achieved by the fact that, in the method of decontaminating effluents of a gold-mining factory, which includes treatment with ozone, according to the invention, neutralization is carried out by ozone supplied in the form of an ozone-oxygen mixture with ozone concentration of not less than 103 g/m³, and constant monitoring and regulation of pH value, which is not less than 11 units, is carried out by addition of lime milk with concentration of calcium oxide of 10 %. throughout the entire decontamination process. Implementation of the method of decontaminating effluents of a gold-mining factory with ozone supplied in the form of an ozone-oxygen mixture at constant monitoring and regulating a pH value of not less than 11 units, during the entire decontamination process, besides removing cyanide- and thiocyanate ions, enables to purify solutions from arsenic, copper and nickel.

EFFECT: technical result of the invention is a single-step complex purification of cyano-containing waste water from sodium cyanide and rhodanide ions to content that meets requirements for recycled and purified water, as well as reduced content of arsenic, copper and nickel.

1 cl