Grinding and Classifying of Rare Earth PowdersTheir Use in Enhancing Quality in the Manufacture of Magnets
Neodymium-iron-boron-magnets (Nd-Fe-B) are so-called rare earth magnets distinguished by their very high energy densities. A decisive factor for the quality and properties of permanent magnets is a narrow particle size distribution with the lowest possible fraction of finest- (< 2 µm) and coarsest particles (> 8 µm).
The NETZSCH company offers innovative solutions to this application problem with a patent pending grinding process with downstream classifying of rare earth powders. The design of this process led to the development of jet mills and ultra-fine classifiers with which sensitive Nd-Fe-B-compounds or other rare earth alloys can be ground reliably to fine powders under inert gas operation giving a narrow particle size distribution and defined upper particle size limit with reproducible results.
With NETZSCH m-Jet, a combination of a spiral jet mill with a dynamic air classifier, highest reproducible finenesses independent of the load in the gas jets are