Abstract:A large number of fluorine-containing sludge generated by photovoltaic power generation industry contains high content of calcium fluoride, which can be used as a resource recycling to realize the reduction, harmless and resource utilization of fluorine-containing sludge. The fluorine-containing sludge was used as raw materials for impurity removal treatment, and the influence of multiple disposals on impurity removal was explored. Based on the moisture content, morphology observation, chemical composition and structure analysis and sedimentation performance test results of fluorine-containing sludge, the technical route of resource utilization of calcium fluoride sludge was optimized. The results show that compared with the two-step and three-step combined treatment, the four-step combined treatment of salinization, acidification, fluorination and alkalization can remove silicon, calcium and heavy metals in non calcium fluoride form more effectively. The mass fraction of calcium fluoride in the fluoride sludge treated by four-step process can reach 85%, and the final yield can reach 72.53%.