Abstract:
Phosphogypsum is a by-product of the wet phosphoric acid production process, with a huge output and a large number of piles in the mine, and the entrained phosphorus and fluorine not only have the risk of leakage and pollute the environment in the process of storage and utilization, but also increase the difficulty of its subsequent utilization. At the same time, phosphorus and fluorine are important resources that support the rapid development of China’s economy and society, and it is of great significance to recycle phosphorus and fluorine resources in phosphogypsum. In this paper, a systematic study of phosphogypsum is carried out by collecting and analyzing relevant literature. In terms of ingredient characteristics, the main component of phosphogypsum is calcium sulfate dihydrate, with a content of up to 80%-90%, containing a certain amount of phosphorus, fluorine and other impurities. Phosphorus exists in the form of soluble phosphorus, insoluble phosphorus and eutectic phosphorus, soluble phosphorus is easy to pollute the environment, insoluble phosphorus can be converted into soluble phosphorus to cause harm, eutectic phosphorus affects the application of phosphogypsum in construction and other fields. Fluorine exists in the form of soluble fluorine and insoluble fluorine, soluble fluorine pollutes groundwater and soil, insoluble fluorine affects soil pH value and endangers the ecological environment. The phosphorus and fluorine recovery methods such as chemical precipitation, adsorption, water washing and purification, electrocoagulation, membrane separation, bioremediation and biological leaching are introduced. The advantages and disadvantages of various methods are summarized, and the phosphorus and fluorine recycling of phosphogypsum is prospected. Joint process integration and collaborative optimization, and complement each other’s advantages are promoted. The process of intelligence and automation, and improve stability is accelerated. Interdisciplinary research is expanded. New ideas and new methods are formed, and the efficient recycling of phosphorus and fluorine resources and the unity of environmental, economic and social benefits are realized.