Desulfurization gypsum promotes the development of circular economy in my country and has a wide range of downstream applications

Desulfurization gypsum, also known as sulfur gypsum, FGD gypsum, flue gas desulfurization gypsum, is a by-product of the sintering flue gas desulfurization process. The moisture content is about 10% to 17%. The main component is calcium sulfate dihydrate, containing sodium ions, chloride ions, There are many impurities such as magnesium ions, among which the content of chloride ions is relatively high. The main ash is silica and iron oxide, and contains a small amount of sodium oxide, calcium sulfite, magnesium chloride, calcium carbonate, etc.

Promoting the use of desulfurized gypsum is of great significance. On the one hand, it can reduce the amount of natural gypsum mined, protect existing gypsum mineral resources, reduce environmental pollution and damage caused during the mining process, and is conducive to sustainable development; on the other hand, the processing of desulfurized gypsum promotes The development of my country’s circular economy has found a new outlet for desulfurization waste and reduced secondary pollution problems caused by the accumulation of desulfurization waste.

According to the “2023-2027 Desulfurization Gypsum Industry In-depth Market Research and Investment Strategy Suggestions Report” released by the Industrial Research Center, my country’s desulfurization Gypsum mainly comes from chemical raw materials and chemical products manufacturing, ferrous metal smelting and rolling processing industry, non-ferrous metal smelting and rolling processing industry, electricity/heat production and supply industry, paper making and paper products industry, non-metallic mineral manufacturing industry, etc. Among them, the electricity/heat production and supply industry is the industry with the largest output of desulfurization gypsum in my country, accounting for more than 80% of the total output of desulfurization gypsum in my country.

Compared with natural gypsum, desulfurized gypsum has the advantages of uniform particles, large specific surface area, renewable recycling, high purity, good stability, less harmful substances, high quality and low price. It is widely used in agriculture, building materials, cement industry, industry Molds, chemicals, food processing and other fields.

In the agricultural field, desulfurization gypsum contains minerals such as calcium ions, silicon ions, and sulfide ions, which can be used as a land conditioner to provide nutrients for plants, adjust soil pH, and increase crop harvests in saline-alkali lands. Desulfurized gypsum can also be used to make fertilizers. Desulfurized gypsum is reacted with cheap ammonium carbonate to produce ammonium sulfate fertilizer that is rich in nutrients and has high product value. The calcium carbonate produced by the reaction can also be used to produce cement.

In the field of building materials, desulfurized gypsum can be used as raw material to produce gypsum boards, gypsum bricks and other building materials, with high production efficiency, low energy consumption, and no waste water or residue is produced during the production process. In the cement field, desulfurized gypsum can be used as a retarder to improve and balance cement strength and adjust cement setting time; desulfurized gypsum can be used to produce alkalinity cement and acts on the glass fiber production process. In addition, desulfurization gypsum can also be used to make highway roadbed fillers, reinforce soft soil foundations, prepare sulfur elements, prepare potash fertilizers, produce tailings cement for filling, produce sulfuric acid, prepare calcium sulfate whiskers, etc.

Industrial analysts said that developed countries have strict regulatory systems for sulfur dioxide emissions. Therefore, in sintering plants, coal-fired industrial boilers, and kilns, Flue gas desulfurization devices are basically installed in furnaces, power plants and other places. The output of desulfurization gypsum is high. In developed countries, the technology is mature and the utilization rate of desulfurization gypsum is high. my country’s desulfurization gypsum industry started late, and the sintering flue gas desulfurization technology is not mature enough, and a complete industrial chain of desulfurization by-products has not been formed. As the country vigorously promotes green energy-saving and environmentally friendly technologies such as integrated desulfurization, denitrification and dust removal during the 14th Five-Year Plan, my country’s desulfurization gypsum has great development potential.