Desulfurization gypsum (English Name: desulfurization gypsum), also known as flue gas desulfurization gypsum, sulfur gypsum or FGD gypsum, is mainly composed of calcium sulfate dihydrate CaSO4 · 2H2O with a content of ≥ 93% like natural gypsum. Desulfurized gypsum is a by-product of FGD process. FGD process is a technology that uses lime limestone to recover sulfur dioxide from coal or oil flue gas. The technology is to grind lime limestone into slurry, so that the flue gas containing SO2 after dust removal passes through the slurry scrubber to remove SO2. Dalian sanding and derusting said that lime slurry reacts with SO2 to produce calcium sulfate and calcium sulfite. Calcium sulfite is oxidized and transformed into calcium sulfate to obtain industrial by-product gypsum, called desulfurization gypsum, which is widely used in building materials and other industries. Its processing and utilization is of great significance. It not only effectively promotes the further development of national environmental protection and circular economy, but also greatly reduces the mining amount of gypsum and protects resources.