Method for separating lanthanide series elements

The invention provides an environment-friendly, efficient and low-cost method for separating lanthanide series elements. The method comprises the following steps that crystals are generated by the lanthanide series elements and boric acid through a fusing hot method, and the crystals of the same structure are separated from crystal lotion or separation is achieved according to drifting in solvent due to the different densities of the crystals of the different structures. The separating method makes selective polymerization for different kinds of lanthanide series metal on the basis of the flexible ligand boric acid, the lanthanide series components are synthesized under the uniform reaction condition for the first time, the lanthanide series elements are divided into six different components, the crystal density is closely related to the crystal structure, the high separation ratio in the binary lanthanide series elements can be achieved, compared with traditional sub-step crystallization, multiple times of separation caused by the low separation ratio is avoided, and generation of a large amount of effluent is avoided.