METHOD FOR CLEANING FLUE GASES OF CALCINATION FURNACES Russian patent published in 2023 - IPC B01D53/56 

FIELD: metallurgy.

SUBSTANCE: used in processes where fuel is burned to produce combustion products containing CO₂, in particular in the process of producing alumina (Al₂O₃) from aluminum hydroxide (Al(OH)₃) in calcination furnaces. A method for purifying flue gases from a calcination furnace in the production of alumina includes (a) supplying flue gases from the calcination furnace sequentially to a multicyclone and an electric precipitator to purify said gases from dust. This is followed by (b) supply of purified gases for wet cleaning into the scrubber. Then (c) irrigation of the gases in the scrubber with a calcination filtrate containing caustic soda with a concentration of at least 16 g/l to obtain a pulp. And then (d) separation of the pulp into liquid and solid phases. In this case, the liquid phase is re-fed to the irrigation stage (c), and the solid phase is returned to the alumina production process at the charge sintering stage.

EFFECT: increasing the degree of purification of the exhaust flue gases of calcination furnaces from dust and reducing the level of CO₂ in the exhaust flue gases.

2 cl, 1 ex, 1 tbl, 1 dwg