METHOD OF PURIFICATION OF SEWAGE Russian patent published in 2000 - IPC

FIELD: chemical industry, more particularly preparation and recovery of useful components from sewage at mining and concentrating mills, metallurgical, chemical and food factories. SUBSTANCE: method comprises two stages for preparation of sewage: first stage is intended for recovering useful components by withdrawing greater part thereof from sewage by deposition with coagulant, and flotation, and second stage is intended for purifying sewage from constituents thereof to permissible concentration of impurities, and is carried out by artificial addition of mineral suspension, coagulant, and surfactant. Undesired impurities are separated by flotation or deposition. Method makes it possible to intensify purification process by combination of condensation, coagulation and flotation processes. EFFECT: more efficient purification method. 5 cl, 1 tbl