Abstract: In order to research the influence of the desulphurization additives on the wet limestonegypsum FGD system, the desulphurization additives experiment had been carried out in the 330MW unit of Hubei Huadian Xisaishan Power Generation Company Limited. The variations of some parameters, such as the contents of CaCO3，Cl- and CaSO3 in the slurry in absorption tower and the CaSO4 content and the water ration in the gypsum before and after the experiment were analyzed. The experiment result shows that by using the desulphurization additives, when the volume fraction of SO2 in flue gas in inlet of absorption tower is 0.7%, the SO2 removal efficiency increased from 92% to 95%, two slurry circulating pumps were shut down, the content of Cl- in absorption tower decreased, the utilization rate of the CaCO3 increased, the gypsum purity increased, and the water ratio of the gypsum was reduced.

Key words: wet limestone-gypsum desulphurization, desulphurization additives, limestone activity, slurry circulating pump, gypsum purity, water ratio of gypsum