Regeneration of magnets to form ND-FE-B magnets with improved or restored magnetic performance

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing a recycled Nd-Fe-B sintered magnet using a magnetic material derived from a waste magnet assembly. SOLUTION: The manufacturing method demagnetizes a magnetic material derived from a waste magnet assembly by periodic heating and cooling of the magnetic material, fragmentes an adhesive adhering to the magnetic material, and forms a coating layer of the magnetic material. A step of cracking and performing at least one mechanical or chemical treatment on the magnetic material to remove the coating layer to prepare an impurity-free magnetic material, the demagnetizing magnetic material. It comprises the steps of fragmenting to form a powder and mixing the powder with the rare earth material R and the element additive A to produce a homogeneous powder. The rare earth material R contains at least one of Nd or Pr, and the element additive A contains at least one of Nd, Pr, Dy, Co, Cu, and Fe. [Selection diagram] FIG. 5