Method for reducing phosphogypsum by using hot carbon, heat activating potassium feldspar, mineralizing CO2 and co-producing SiO2 and potassium sulfate

Abstract

The invention discloses a novel mineralization method for utilizing CO2. The method comprises the following steps: firstly, uniformly mixing potassium feldspar ore powder, calcium sulfate and carbon powder, forming through a tabletting or agglomerating method; roasting the formed material under nitrogen gas atmosphere, recycling and applying the generated SO2 to sulfuric acid industry; grinding and sieving the roasted product, subjecting the sieved product to mineralization reaction with CO2; filtering and separating the mineralized liquid-solid mixture, and evaporating the filtrate and performing crystallization to prepare potassium sulfate, and the filter residue comprises CaCO3, CaSiO3, aluminosilicate and the like and can be used as a cement material. According to the invention, industrial solid waste phosphogypsum can be reduced, so that the product can be applied to the sulfuric acid industry, and meanwhile, the environment problem can be solved; the CO2 carbonation characteristic is fully utilized, and mineralization and carbon reduction are carried out; the water-insoluble potassium feldspar ore is processed into a water-soluble potassium sulfate fertilizer; a co-melt is formed in the reaction process of reactants, the temperature required by reaction is reduced, and the energy consumption is reduced. The method has the triple effects of saving energy, reducing carbon,protecting environment and producing a chemical, and has a very good industrial application prospect.

Description

technical field [0001] The present invention relates to a kind of utilizing mineral to mineralize CO 2 to fixed CO 2 The purpose of the method is specifically related to the use of thermal carbon reduction of phosphogypsum coupled with thermal activation of potassium feldspar mineralization of CO 2 Parallel production of SO 2 and potassium sulfate method. Background technique [0002] The world economy is growing strongly, and the rapid development of science and technology has greatly improved the quality of human life, which also drives huge energy consumption. Carbon dioxide released by human activities is an important greenhouse gas that causes global warming. Global warming has seriously affected the global climate and ecological environment, including the movement of climate zones, sea level rise and land inundation, changes in ocean currents, vegetation migration and species extinction, frequent El Nino, etc. The concentration of carbon dioxide in the global atmos...

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Problems solved by technology

Due to the high impurity and high calcining energy of phosphogypsum, the quality of gypsum boards, bricks and blocks produced by phosphogypsum is not stable, and the strength is low, and the water resistance is poor. Gypsum is slightly less, and its impurities are far lower than phosphogypsum), and phosphogypsum building material products are still shrinking further

[0014] Since the 1950s in my country, the research work on gypsum decomposition to produce sulfuric acid co-production cement has been carried out. However, due to the high decomposition temperature and the problem of key equipment that has not been effectively solved for a long time, it is difficult to popularize and apply it so far.

In the 1980s, Sanhuan Chemical Co., Ltd. (formerly Yunnan Phosphate Fertilizer Factory), a subsidiary company of Yuntianhua Group, built a set of cement raw material equipment with an annual output of 100,000 tons of sulfuric acid from phosphogypsum using dry-process hollow kiln technology. Since commissioning in 1987, due to the high energy consumption of the rotary kiln, the low decomposition rate of phosphogypsum, the unstable quality of cement clinker, and unreasonable economics, it has not been put into production.

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