Abstract：In order to solve the urgent need for treatment of ammonium chloride wastewater produced by rare earth extraction and separation, according to the composition of rare earth wastewater, the advantages and disadvantages of evaporation crystallization method, multi-effect evaporation method, break point chloride method, ammonia stripping method, ammonium magnesium phosphate method, MVR evaporation and other processes are comprehensively compared from the aspects of process principle and application scope. The results show that the cost of using tri-effect evaporation steam can be reduced to ￥125.56/t,and suitable for less than 10 000 t/a of rare earth extraction separation enterprises.Refer to electrodialysis, ion exchange, biological treatment, SBR process and other treatment schemes that have not been applied and popularized,The combination of pretreatment+preconcentration+triple effect was proposed. The results show that the combination scheme not only reduces energy consumption, but also realizes ammonia nitrogen treatment. At the same time, ammonia nitrogen and water resources can be recycled and utilized. The byproduct ammonium chloride forms a new profit point, which can be used as raw materials in chemical fertilizer industry.
