METHOD OF COMPLEX PROCESSING OF WASTEWATER GALVANIC PRODUCTION Russian patent published in 2018 - IPC C02F9/10 C02F1/70 C02F1/62 C22B5/04 C22B34/32 C02F101/22 C02F103/16 

FIELD: technological processes.

SUBSTANCE: invention can be used in electroplating in the processes of chromium plating, chemical oxidation, electrochemical polishing, etching and passivation of metals and alloys. Method involves treating chrome-containing waste water with a solution of Na₂SO₃, alkalescency with 10 % NaOH solution to 3÷5 pH, processing of the obtained material with ferrite suspension, previously prepared by mixing, pts. wt. including: FeSO₄ – 10, NaOH – 3, NaNO₃ – 1. Ferritic suspension is injected at the rate of 1÷2 g of iron contained in the resulting suspension per 1 g of contaminating metals, and not less than 80÷100 mg of iron per 1 liter of wastewater. After that, re-alkalescency is carried out with 10 % NaOH solution to 7÷9 pH to obtain a chromium precipitate. Separation of the precipitate from the solution is carried out on a magnetic separator, its heat treatment is carried out in two stages: at 180÷200 °C for 1.5÷2.0 hours and at 450÷550 °C for 15÷30 min. To the heat-treated precipitate, in a stoichiometric ratio, aluminum grains obtained by grinding aluminum waste are added, and aluminothermic reduction is carried out to produce ferrochrome and aluminothermic slag.

EFFECT: method provides higher efficiency of processing of chromium-containing industrial wastewater while reducing the cost of implementing the method and expanding the range of commercial products obtained.

3 cl, 1 ex