A method for preparing high-strength gypsum by normal-pressure solution method

Abstract

The invention provides a method for preparing high-strength gypsum by adopting an atmospheric pressure solution. The method comprises the following steps: preparing a composite chloride salt solution with a mass concentration of 5-30 %; stirring and heating the composite chloride salt solution to 65-96 DEC G and keeping the constant temperature stably for 30 min; then, adding flue gas desulfurization gypsum with the mass concentration of 5-20 % and organic acids crystal modifier with the mass concentration of 0.1-1.8 % to the composite chlorate solution; controlling the reaction temperature and keeping the reaction temperature at the pre-arranged temperature; in a reaction condition of 5 to 8 pH value and 0.5-6 h stirring time, quickly filtering the mixed slurry with hot water of 95-98 DEC G; obtaining the high-strength gypsum after drying and powder grinding. According to the invention, building materials recycling of the desulfurized gypsum and the high-strength gypsum is realized; the wastes are changed into valuable, so that the method provided by the invention has remarkable social, environmental and economic benefits; pressure vessels are not required during the technological process; the energy consumption is low; the equipment is simple; the operation is convenient; the reaction conditions are easy to control; the obtained product is uniform in crystal structure and stable in quality; the standard consistency of water is 43%; the rupture strength reaches 5.34 M pa within two hours; the absolutely dry strength of the high-strength gypsum reaches 30.21 M pa.

Description

technical field [0001] The invention relates to the technical field of building raw material preparation, in particular to a method for preparing high-strength gypsum by an atmospheric pressure solution method. Background technique [0002] As we all know, my country's energy structure is dominated by coal combustion, which generally has a high sulfur content, and the vast majority of sulfur dioxide emissions come from coal combustion, causing serious pollution. In order to solve the environmental problems caused by industrial waste gas, the government stipulates in legal form that the coal-fired flue gas must be desulfurized. At present, the leading technology for the prevention and control of flue gas pollution in domestic coal-fired power plants is the wet limestone-gypsum method, and its market share is as high as 90%, the result of this is that the output of desulfurization gypsum increases rapidly with the construction and operation of flue gas desulfurization equipmen...

AI Technical Summary

Problems solved by technology

Although the first three production processes are relatively mature, their practical application is greatly restricted due to lengthy process, complex equipment, large initial investment and high energy consumption.

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