METHOD OF PURIFYING WASTE WATER FROM THIOCYANATES Russian patent published in 2010 - IPC C02F1/72 C01C3/20 C02F101/18 C02F103/16 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of purifying waste water from non-ferrous metallurgical factories, gold mining industries etc, which contain thiocyanates (rhodanides). To realise the method, waste water containing thiocyanates is treated with hydrogen peroxide in an acidic medium in the presence of atmospheric oxygen and a catalyst to form hydrocyanic acid which is blown and absorbed by an alkali metal hydroxide. The catalyst used is a catalyst system which contains dissolved iron (III) and copper (II) salts. The mixture of iron (III) and copper (II) salts is taken in ratio [SCN^-]: [Fe³⁺]: [Cu²⁺]= 5:1: 0.2.

EFFECT: method ensures high degree of purity of waste water with consumption of the oxidising agent close to stoichiometric consumption, considerably lowers operating costs and cost of the purification process by recycling valuable product - alkali metal cyanide; also the proposed method is simple to implement.

2 cl, 5 ex