Desulfurized Gypsum

Desulfurized gypsum is an industrial by-product gypsum obtained after the flue gas produced by the combustion of sulfur-containing fuel is desulfurized and purified by fine lime or limestone powder slurry. Its chemical composition is the same as that of natural dihydrate gypsum, mainly CaSO4·2H2O. At present, coal-fired power generation is still the main power generation method in my country, and SO2 emitted by coal in the process of thermal power generation accounts for more than 50% of my country's annual emissions. The massive emission of sulfur dioxide causes serious environmental pollution. The use of flue gas desulfurization technology to generate desulfurized gypsum is an important measure to solve the technological development of coal-fired related industries. According to incomplete statistics, the emission of wet desulfurization gypsum in my country has exceeded 90 million t/a, and the treatment method of desulfurization gypsum is mainly stacking, which not only occupies land, but also causes huge waste of resources.

Gypsum has the functions of light weight, noise reduction, fire prevention, thermal insulation, etc. It can be used in cement production, building gypsum production, decoration engineering and other fields. At present, many scholars have carried out research on plastering plaster. The research shows that gypsum plastering material has micro-expansion, good workability and plasticity, and can replace traditional plastering materials and be used in interior wall decoration. Xu Jianjun and other studies have shown that desulfurized gypsum can be used to make lightweight wall materials. Studies by Ye Beihong and others have shown that the plastering gypsum produced by using desulfurized gypsum can be used for the plastering layer of the inner side of the outer wall, the inner partition wall and the ceiling, and at the same time, it can solve the common quality problems such as shelling and cracking of traditional plastering mortar. Lightweight plastering plaster is a new type of environmentally friendly plastering material. It uses hemihydrate gypsum as the main cementing material and is prepared by adding lightweight aggregates and additives. Compared with traditional cement plastering materials, it is less prone to cracking and sticking. It has the advantages of good knotting, good shrinkage, green environmental protection and so on. The use of desulfurized gypsum to produce hemihydrate gypsum not only solves the problem of lack of natural building gypsum resources, but also realizes the resource utilization of desulfurized gypsum, and achieves the purpose of protecting the ecological environment. Therefore, on the basis of the research on desulfurization gypsum, this paper tests the setting time, flexural strength and flexural strength of light plaster desulfurization gypsum with different gypsum powder content, light aggregate content, retarder content and cellulose ether content. Compressive strength, study the factors affecting the performance of lightweight plastering desulfurization gypsum mortar, and provide a theoretical basis for the development of lightweight plastering desulfurization gypsum mortar.