The Application Of Flue Gas Desulfurization Gypsum On Building Materials From Yao-Meng Power Co., Ltd.

With the sustained and rapid development of our national economy, great material wealth were created as well as serious problems about environment and natural resources.Therefore, much attention has been paid on energy savings and pollutant reductions. In a long period in the future, yield of flue gas desulfurization gypsum (FGD gypsum) increases with the continuous installation of flue gas desulfurization apparatus.FGD gypsum is a waste of coal-fired power plant, comprehensive utilization of FGD gypsum is of great significance to economy and environment, which not only can reduce the land occupation of desulfurization products of coal-fired power plant, reduce the secondary pollution, but also can partly replace natural gypsum resources. As a consequence, there is a growing interest in looking for avenues where the FGD gypsum can be used of value added products, which have great significance to realize sustainable development and the value added comprehensive utilization of FGD gypsum.In this paper, characteristic differences between FGD gypsum and natural gypsum were investigated by chemical analysis, differential thermal analysis (DSC) and X-ray diffraction analysis (XRD).The results show that FGD gypsum has similar performance in the physical properties, chemical properties and mineral composition to natural gypsum. Both of them the main component were dihydrate calcium sulphate (CaSO4·2H2O).The particle size of FGD gypsum was finer than natural gypsum. FGD gypsum was easy to lose crystal water. In this paper, the effect of drying temperature and drying time on mechanical properties of FGD gypsum, for improving the application value of FGD gypsum. The study found that mechanical properties of FGD gypsum was best which dried at 190℃for two hours. FGD gypsum can be used as building gypsum.FGD gypsum was taken as raw materials in place of natural gypsum as cement retarder. The effects of process conditions such as FGD gypsum content and drying temperature of FGD gypsum on Portland cement, ordinary Portland cement and slag cement were studied. The results show that FGD gypsum can be used as a substitute for natural gypsum cement retarder. The performance of Portland cement, ordinary Portland cement and slag cement were best when FGD gypsum content was 4%.The setting time of cement was impacted by drying temperature of FGD gypsum. Setting time of cement was extended with the drying temperature of FGD gypsum was increased.In this paper, FGD gypsum was used in polymer-modified cement compounds for waterproofing membrane. The impact of FGD gypsum amount and cement type on self-closing performance was studied. The results show that the self-closing performance of polymer-modified cement compounds for waterproofing membrane was best when FGD gypsum content was 20%.When use ordinary Portland cement, the self-closing performance of polymer-modified cement compounds for waterproofing membrane was better than use alumina cement and expansive cement.