Experimental Study on Median Temperature Sulfur Fixation Characteristics and Mechanism in Flue Gas of Alkaliferous Industry Waste

The median temperature sulfur fixation characteristics in flue gas of experimental wastes were studied by tube furnace, the phase composition and mineral content of sulfur fixation product were analyzed by XRD and thermal gravimetric, median-temperature sulfur fixation mechanism of alkali industrial waste were discussed, which provide theoretical basis for preparation of waste type median-temperature sulfur fixation agents. It can be found that some experiments alkali industrial waste such as: alkali slag, red mud and salt slurry have better sulfur fixation characteristics because of rich in Al₂O₃, Fe₂O₃ and SiO₂, and so on, On the one hand, Al₂O₃, SiO₂ and Fe₂O₃ make initial grain size of carbonate crystallization small and dispersion high, which can increase surface area of sulfur fixation reaction, thin product thickness, reduce diffusion resistance of product layer and raise the proportion of carbonate forming sulfate, on the other hand, Al₂O₃, SiO₂ and Fe₂O₃ play the role of transferring oxygen during the formation process of CaSO₄, which result in CaSO₃ is easily oxidized and form sulfate calcium.