Abstract: Dongfang power plant came across many unqualified cases in the year of producing FGD gypsum. By analyzing the cause of unqualified gypsum in Dongfang power plant,it is found out that the main influencing factors of the quality include the operating conditions deviating from the design parameter of desulfurization system, the limited mixed burning of coal, the low efficiency of ESP and the insufficient output of gypsum cyclone separator. Therefore, this paper puts forward three improvement approaches:by controlling the entrance flue gas, by controlling the operational parameters of desulfurization system, and by strengthening the analysis work in environmental laboratory.

Key words: the quality of gypsum, reason analysis, equipment modification, operational control