The main components of desulfurized gypsum are the same as those of natural gypsum. They are both calcium sulfate dihydrate (CaSO4·2H2O). The color is slightly yellow, neutral or slightly alkaline. The physical and chemical properties of natural gypsum have the same laws. However, as an industrial by-product, desulfurized gypsum has its own characteristics compared with natural gypsum, which are mainly manifested in the appearance, chemical composition, especially impurities, particle morphology and other properties that are significantly different from those of natural gypsum. In addition, the grade of desulfurized gypsum is slightly higher than that of natural gypsum, and it contains less impurities, making it a chemical gypsum of better quality.

1. Physical properties of desulfurized gypsum
The particle characteristics and physical state of desulfurized gypsum are also quite different from those of natural gypsum. Desulfurization gypsum contains 10%-15% of attached water and is in the form of wet powder. The appearance of normal desulfurized gypsum is almost white, and it is yellow-white or gray-brown with the change of impurity content. Desulfurized gypsum is finer than natural gypsum, with a particle size generally not exceeding 90μm, and more than 85% of the particle size is between 30μm and 60μm. The gradation is not as good as that of finely ground natural gypsum. The coarse particles of natural gypsum after grinding are mostly impurities, and the fine particles are mostly gypsum, while the coarse particles of desulfurized gypsum are mostly gypsum and the fine particles are mostly impurities. For the above reasons, although desulfurized gypsum is fine, its specific surface area is not as good as natural gypsum.
 
2. Chemical properties of desulfurized gypsum
In terms of chemical composition, the main components of desulfurized gypsum and natural gypsum are calcium sulfate dihydrate. The content of calcium sulfate dihydrate in desulfurized gypsum is higher than 90%, which is higher than 70% to 80% in natural gypsum. It can be seen from Table 1 that the free water content of desulfurized gypsum is generally about 10%, and it also contains fly ash, organic carbon, calcium carbonate, calcium sulfite, and soluble salts composed of sulfates or chlorides of sodium, potassium, and magnesium, etc. Impurities. It can be seen from Table 1 that the chemical composition of the two is very similar. During the use of desulfurized gypsum, the concentration of some soluble salts, such as potassium, sodium, and chloride ions, must be strictly controlled.
 
3. Comparison of chemical composition between desulfurized gypsum and natural gypsum

 
Henan Zhengzhou Mining Machinery Co., Ltd. is a supplier of integrated desulfurization gypsum disposal solutions. It has technical support from experts in metallurgy, building materials, and chemical industries, and has long-term cooperation with the School of Chemical Engineering of Zhengzhou University. With a skilled process route and a professional mechanical design team, the company has built a pilot test production line to meet various test needs. The company is also a supplier of complete sets of equipment. Can do all the processes from design, construction, installation, and debugging, in the decades of continuous development of the company, we have been committed to contributing to the cause of environmental protection, adhering to the concept of "morality in advance, benefits for others", and efficient service to every customer.