Rare Earths

Optimum processing for high-performance magnets

Rare earths as a component of neodymium-iron-boron alloys (NdFeB) or samarium-cobalt alloys (SmCo) are used to produce magnets that are used in electric motors, among other things. They therefore play an important role in electromobility, but also in aviation, wind turbines and medical technology. The performance of the magnets depends crucially on the quality of their ingredients. Optimised processing of the rare earths is particularly important here, and Hosokawa Alpine has developed the ideal process for this.

Grinding of rare earths

With the AFG-R jet mill

One of the major challenges in processing NdFeB is that neodymium is pyrophoric: very fine particles oxidise when they come into contact with oxygen. A system for processing the material must therefore be gas-tight and run with inert gas (nitrogen or argon). An integrated passivation process is also required, which fills the system with air in a controlled manner when it needs to be opened. This allows even the smallest particles to oxidise in a controlled manner without causing damage.

The AFG-R fluidised bed counter jet mill from Hosokawa Alpine fulfils these requirements. This version of the AFG jet mill has a bottom nozzle so that even difficult-to-grind particles can be ground. At the same time, it produces ultra-fine particles with a fineness of d₅₀ < 3-5 µm to produce extremely strong magnets.

Find out more about processing rare earths!