Method for extracting rare earth elements from mixed rare earth concentrate through chlorination and comprehensively utilizing rare earth elements

The invention discloses a method for extracting rare earth elements from mixed rare earth concentrate through chlorination and comprehensively utilizing the rare earth elements, and belongs to the field of comprehensive utilization and recovery of rare earth. The rare earth concentrate serves as a raw material, chlorine serves as a chlorinating agent, carbon monoxide serves as a reducing agent, aluminum oxide serves as a fluorine-fixing and phosphorus-fixing agent, and oxygen serves as a heat regulator; high-temperature flue gas containing carbon monoxide generated by oxygen-enriched and oxygen-deficient combustion of a gas-fired boiler is used as a heat source and a carbon source to carry out a rare earth carbon thermal chlorination reaction. The final products of the method comprise calcium phosphate solids, a sodium aluminate solution, alkaline earth metal precipitates, rare earth oxides, carbon dioxide, hydrogen, chlorine and the like. Compared with a traditional utilization method, aluminum fluoride and