Abstract:The flotation purification technology of phosphogypsum was studied in view of the by-product of wet phosphoric acid in a large phosphorus chemical industry in Yunnan. The research shows that when the pulp pH is 1.3 and the dosage of collector YP8-2 is 0.3kg/t, the mineral processing index of 97.63% CaSO4.2H2O content and 94.72% recovery can be obtained through the full-size "one coarse, two fine and one sweep" direct flotation closed circuit process; Through the direct flotation closed circuit process flow of "one coarse, one fine and one sweep", the beneficiation index with the content of CaSO4.2H2O of 98.92% and the recovery of 98.19% can be obtained. The results of the purification test of gypsum, a by-product of phosphoric acid industry, provide pretreatment technology for the high value utilization of phosphogypsum resources.