Research progress in preparation and purification methods of high-purity dysprosium and terbium metals

High purity dysprosium and terbium metals serve as the fundamental raw materials in various fields, including permanent magnet materials, magnetostrictive materials, magneto-optical storage materials, magnetic refrigeration materials and electric light source materials. The calcium thermal reduction method and the intermediate alloying method used in the preparation of industrial pure dysprosium and terbium metals are summarized, and the vacuum distillation method, zone melting method and solid state electromigration method are described in detail. The technology of hydrogen ionization arc melting, electrochemical deoxidation and solid phase external inspiratory are also summarized. Finally, we considers the future development direction of high purity dysprosium and terbium metals from the perspective of market orientation and operability, and provides reference for the development of high purity rare earth metals dysprosium and terbium industries.