Papers by Keyword: Natural Gypsum

Abstract: The properties of various thermal modifications and forms of calcium sulfate and the conditions of their mutual transition are studied. It is established that the mode of heat treatment of gypsum raw materials affects significantly the nature of the subsequent hydration of the gypsum binder. It is established that the values of pH and pCa suspensions of gypsum binders depend on the temperature of heat treatment of natural gypsum, vary over time and characterize the processes occurring during hydration and hardening of gypsum binders. The values of pH and pCa suspensions of gypsum binders can serve as design criteria for innovative multiphase gypsum binders.

Abstract: In article the question of use of pressure for receiving quality products on the basis of gypsum is considered. Correlation of characteristics of a raw mix and properties of a material is researched. Are used as input products natural and technogenic gypsum.

Abstract: In this paper, the flue gas desulfurization gypsum (FGD) generated from thermal power plant is used to produce high strength gypsum. The basic properties of super high strength gypsum prepared by FGD gypsum are investigated based on the test results of strength, thermal expansion rate, crystal appearance and size. The results indicate that the properties of high strength gypsum prepared by FGD gypsum above α50 standard. This can be a reference for gypsum-based α super high-strength gypsum related product development.

Abstract: In this paper, the flue gas desulfurization gypsum (FGD) generated from thermal power plant is used to produce high strength gypsum. Compared with the properties of high strength gypsum using natural gypsum, the basic properties of super high strength gypsum prepared by FGD gypsum are investigated based on the test results of strength, thermal expansion rate, crystal appearance and size. The results indicate there is little difference of the properties of high strength gypsum prepared by FGD gypsum and natural gypsum. And furthermore, the FGD gypsum can be used as the good raw material of high strength gypsum preparation instead of natural gypsum.

Abstract: In this work, the solubility of phosphogypsum(PG) in water and saturated lime solution was determined in experiments carried out at different temperatures from 10 to 50°C. The solubility of natural gypsum(NG) was also studied at an attempt to find out differences in solubility between PG and NG due to the effect of impurities. The results show that in pure water media, PG dissolves more rapidly than NG at early time, and then equally with NG. With increasing the temperature of water, the dissolution rates PG decreased while that of NG increased. In saturated lime solution, compared with NG, the solubility of PG was distinctly influenced due to the existence of impurities. Possible reaction among soluble impurities and calcium ion retarded the dissolution of calcium sulfate dihydrate.