SYSTEM AND METHOD FOR DESULFURIZATION AND DENITRIFICATION OF ALUMINA CALCINATION FLUE GAS, AND USE

摘要

Disclosed are a system and a method for desulfurization and denitrification of an alumina calcination flue gas, and a use. The system comprises an ozone generator (1), a red mud pre-impregnation slurry scrubbing tower (3), and a red mud pre-impregnation tank (5) and a red mud pre-impregnation clear liquid scrubbing tower (10). NO _x in a flue gas is oxidized into a high valence oxynitride by ozone, and with the red mud as an absorbent, the synergistic absorption of SO ₂ and NO _x in the flue gas is achieved, while the dealkalization of the red mud is achieved. By means of the synergistic catalytic oxidation of metal ions such as Fe ³⁺ in a red mud slurry and ozone, the synergistic absorption of sulfur and oxynitride is promoted and the material consumption of the subsequent desulfurization and denitrification is reduced; and the use of a structure of staged absorption in two towers overcomes the problem of the difficulty in absorbing NO ₂ with a low O ₃/NO _X molar ratio by enhancing absorption with sodium alkali in a second stage tower, while decreasing the consumption of and risk of escape of the ozone, wherein same has the advantages of a high purification efficiency and a low operation cost, and has a stronger applicability to the alumina calcination flue gas.