METHOD OF RECYCLING RARE EARTH MAGNET POWDER

摘要

PROBLEM TO BE SOLVED: To provide a method of recycling rare earth magnet powder as rare earth bonded magnet material which uses thermosetting resin as a binder without deteriorating it in magnetic properties. SOLUTION: This recycling method comprises at least a process of recovering a mixed powder of rare earth magnet powder and resin from a rare earth bonded magnet which uses thermosetting resin as a binder. Resin which binds rare earth magnet powder together in the rare earth bonded magnet is decomposed, and the other resin which covers the rare earth magnet powder is not decomposed. Thereafter, the bonded magnet pieces subjected to a resin decomposing process are ground into a mixed powder by application of a force, and a mixed powder of rare earth magnet powder of desirable grain size and resin powder is recovered from the above the mixed powder by classification. Or, a grinding process is so carried out as to enable grains which are 100 μm or below in diameter and contained in the recovered mixed powder of rare earth magnet powder and resin powder to amount to 40 wt.%. The recovered mixed powder of rare earth magnet powder and resin powder is substituted for a part or all of virgin rare earth magnet powder so as to be reused.