Gypsum, is solid waste of the fertilizer, phosphoric acid production emissions. With the development of phosphate fertilizer industry in recent years, emissions of gypsum are increased to more than 10 million tons/y of phosphorus. Those large number of discharged gypsum waste, will take up land, cause serious environmental pollution, so reasonable conversion of gypsum resources is seriously and immediately. gypsum mill is important.

Gypsum is an important renewable resource, containing phosphorus, fluorine and other magazines, the main chemical components are CaO and SO3. gypsum mainly exist in four types of crystalline needles, tabular crystals, dense crystalline, crystal nuclei form. In phosphoric acid production process, part of the phosphate rock is not decomposed, gypsum washing the filtration process is not completely and the addition of additive are all reasons of gypsum containing phosphorus, fluorine and other impurities. gypsum can be used in pharmacy industry.

Ways and methods of gypsum recycling are: the produce of construction gypsum powder, gypsum board and gypsum block; as cement retarder, production of cement and sulfuric acid and ammonium sulfate; can be made into paper filler; can be used as soil conditioner in agriculture field.

Recently, an innovative of new technology is to extract rare earth elements from gypsum. Poland had reported this technology as early as in the 1990s about extracting rare earths from apatite; and our country carried out a experimental study of launched comprehensive utilization of gypsum and extraction of rare earths, it is learned that this innovative technology can solve three problems once: extracting important rare earth metals from industrial waste, gypsum building materials, and waste recycling.