METHOD FOR WET CLEANING OF WASTE GAS FROM POT ROOMS OF ALUMINIUM PRODUCTION Russian patent published in 2009 - IPC B01D53/14 C01F11/22 C01D5/00 

FIELD: technological processes.

SUBSTANCE: invention is related to non-ferrous metallurgy and may be used for cleaning of waste gas of pot rooms of aluminium production from remains of hydrogen fluoride and sulphur dioxide with production of sodium sulfate and calcium fluoride as finished products. Waste gas of pot rooms of aluminium production is exposed to cleaning from hydrogen fluoride and sulphur dioxide by means of its irrigation in wet scrubbers with soda-sulfate solution. After wet cleaning of gases 4-10%, soda-sulfate solution is cleaned from fluorine, and calcium fluoride is extracted from it. The remaining solution is returned for gas cleaning. Soda-sulfate solution cleaned from fluorine is exposed to evaporation with extraction of waterless sodium sulfate. Evaporated mother water is mixed with fresh-made soda-alkaline solution and returned to wet gas cleaning together with the main soda-sulfate solution.

EFFECT: makes it possible to prepare high-quality waterless sodium sulfate and to exclude losses of soda, which makes it possible to reduce soda consumption 1,2-1,5 times.

1 cl, 2 dwg, 1 tbl