Abstract:In order to make the smelting flue gas emissions of the four industrial silicon production lines in Yonglong Company of Mangshi meet the current national and local air pollutant emission standards, based on the silicon smelting process, the limestone-gypsum process was used for desulfurization transformation. The cores of desulfurization system were SO2 absorption system, the limestone slurry preparation and storage system, and the gypsum dehydration system. The flue gas parameters before and after desulfurization were compared. The results showed that the concentration of SO2 and NOx in exhaust gas was less than 150mg/Nm3, which was better than the emission requirements of pollutants in key areas. The dust emission was less than 50mg/Nm3, which meet the national and local pollution emission standards.