METHOD FOR PRODUCTION OF RARE EARTH ALLOY FINE POWDER

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PROBLEM TO BE SOLVED : To provide a method for production of rare earth alloy fine powders by which the rare earth alloy fine powders of a low oxygen content for high magnetic properties are obtained and handling of the rare earth alloy fine powders remaining in a pulverizing system is facilitated. SOLUTION : The method for production of the rare earth alloy fine powders comprises pneumatically pulverizing raw material alloy crude powders containing rare earth elements by using a pulverizing system. For example, the pneumatic pulverization is performed in the state of maintaining the oxygen concentration within the closed circuit of the pulverizing system at <0.2% and during the pneumatic pulverization and/or after the pneumatic pulverization, vibration is applied to at least a part of piping constituting the pulverizing system. Also, the inner wall of at least a part of the piping constituting the pulverizing system may be formed to a surface roughness subjected to polishing by a grinding wheel using abrasive grains of grain size ≥#100 stipulated in Japanese Industrial Standards (JIS R6001). Further, at least a part of the piping constituting the pulverizing system may be grounded. Further also, at least a part of the piping constituting the pulverizing system may be composed of a non-magnetic material. During the pneumatic pulverization, AC magnetic fields may be applied from the outside to the piping composed of the non-magnetic material. COPYRIGHT : (C)2007, JPO&INPIT