A novel method for purification of phosphogypsum
Jinming Wang 1, 2  
,   Faqin Dong 1, 3,   Zhaojia Wang 2, 4,   Feihua Yang 2, 4,   Mingxia Du 1, 3,   Kaibin Fu 1, 3,   Zhen Wang 1, 3
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Southwest University of Science and Technology
Beijing Building Materials Academy of Sciences Research Co., Ltd
Key Laboratory of Solid Waste Treatment and Resource Recycle Ministry of Education
State Key Laboratory of Solid Waste Reuse for Building Materials
Jinming Wang   

Southwest University of Science and Technology
Publication date: 2020-09-25
Physicochem. Probl. Miner. Process. 2020;56(5):975–983
Phosphogypsum is an industrial solid waste from the phosphate fertilizer industry. At present, the accumulation of phosphogypsum has caused very serious economic and environmental problems. A large scale of phosphogypsum is consunmed in the building field. The characteristics of whiteness and phosphorus content are important factors affecting the use of phosphogypsum as a building material. In this study, soluble phosphorus and fluorine were removed by adding lime, and flotation was employed to purify phosphogypsum. A large amount of organic matter and fine slime in the phosphogypsum were removed by reverse flotation, and gypsum was floated by positive flotation. Through the flotation closed-circuit experiment, the whiteness of phosphogypsum was increased from 31.5 to 58.4, the percentage of total phosphorus in gypsum (P2O5) was reduced from 1.78 to 0.89, the grade of calcium sulphate dihydrate was 96.6%, the recovery of concentrate was 74.1%. After removing impurities, the phosphogypsum concentrate reached the first grade national standard of the phosphogypsum building materials in China. The method is cheap and practical, and can be used as an important method for pretreatment of phosphogypsum.