“…In the rare earth smelting and separation process, due to processes such as saponification of the extractant, a large amount of ammonia nitrogen wastewater would be produced, which contains high concentrations of calcium and sodium ions, accompanied by a small amount of radioactive elements and heavy metals. The composition of rare earth sewage is complicated and difficult to treat [4,5]. If discharged directly without treatment, it would cause great harm to the environment.…”