METHOD OF INDUSTRIAL WASTE WATER PURIFICATION FROM HEAVY METALS Russian patent published in 2020 - IPC C02F1/62 

FIELD: water treatment.

SUBSTANCE: invention relates to the technology of cleaning waste water from metallurgical, chemical and other industries from toxic substances and using purified effluents in a recycling cycle of enterprises. Purification of acid waste water from heavy metals involves stepwise deposition of heavy metals using alkaline solutions and subsequent precipitation. At the first step, acid waste water is neutralized in the reactor at temperature of 70…80 °C to pH 4.0…4.5 by dust of limestone with subsequent neutralization by dust of dolomite carryover to pH 7.0…8.0. At the second stage, the suspension is fed into an intermediate vessel, ferrosilicon micro spray is added, thoroughly mixed, and then the suspension is transferred to a radial settler, cooled to 25–30 °C, separated effluents are separated into treated sewage water tank. Solid mixture is transferred to third stage - in combined drier of "boiling bed", where it is simultaneously dried at temperature 130…140 °C and grinding to 10…15 mcm for 25…30 min.

EFFECT: invention provides efficient treatment of industrial waste water from heavy metals with simultaneous production of green gypsum.

1 cl, 5 tbl, 1 dwg