Abstract: A 2 million t/a graterotary kiln flue gas desulfurization unit is based on a single tower single cycle limestonegypsum wet flue gas desulfurization technology.With the promotion and implementation of ultralow emission in the steel industry,the existing desulfurization devices cannot meet the new environmental emission requirements,so the original desulfurization system needs to be improved.The reconstruction using single pylon dual cycle limestonegypsum wet desulphurization process,on the basis of the original desulfurization absorption tower increased partition spray after lifting,and increase the spray layer,the outside of absorber tower increase new external loop slurry box,and the cycle of form a complete set of slurry pump,as well as the process water system for pulp,the limestone slurry preparation system,compressed air system and gypsum dewatering system renovation design of related.After the efficiency enhancement transformation of the desulfurization system according to the optimized design,the SO2 concentration at the desulfurization tower outlet is no more than 35 mg/Nm3,and the droplet emission concentration is no more than 50 mg/Nm3.After the implementation of the project,the emission concentration of sulfur dioxide has been greatly reduced,reaching the ultralow emission standard,and the environmental benefits are very obvious.

Key words: Gratekiln, Wet flue gas desulfurization, Dual cycle, Desulfurization improving