The University of Birmingham

Allan Walton

Ivor Rex Harris

John D Speight

Andrew Williams

Oliver Peter Brooks

Neil Rowson

John Speight

A method of processing NdFeB magnetic powder comprises: providing a source of hydrogenated NdFeB powder (); feeding said powder into an inlet of a cyclone separator (); separating the powder into an overflow enriched in Nd-rich grain boundary phase and an underflow enriched in NdFeBHmatrix phase particles (); optionally feeding the underflow back into the inlet of the cyclone separator whereby to further enrich the underflow in the NdFeBHmatrix phase particles (); and collecting the underflow ().

Processing of NdFeB magnetic material

A process is provided for the production of rare earth magnets comprising the steps of exposing a rare earth alloy to hydrogen gas at an elevated temperature so as to effect hydrogenation and disproportionation of the alloy, mechanically processing the disproportionated alloy, and degassing the processed alloy so as to effect hydrogen desorption and recombination of the alloy. The process of the invention finds use in the production and shaping of rare earth magnets, and may be particularly applicable to the production of thin magnetic sheets.

Magnet production

The present invention discloses a method for recovering rare earth particulate material from an assembly comprising a rare earth magnet and comprises the steps of exposing the assembly to hydrogen gas to effect hydrogen decrepitation of the rare earth magnet to produce a rare earth particulate material, and separating the rare earth particulate material from the rest of the assembly. The invention also resides in an apparatus for separating rare earth particulate material from an assembly comprising a rare earth magnet. The apparatus comprises a reaction vessel having an opening which can be closed to form a gas-tight seal, a separator for separating the rare earth particulate material from the assembly, and a collector for collecting the rare earth particulate material. The reaction vessel is connected to a vacuum pump and a gas control system, and the gas control system controls the supply of hydrogen gas to the reaction vessel.

Magnet recycling

The present invention discloses a method for recovering rare earth particulate material from an assembly comprising a rare earth magnet and comprises the steps of exposing the assembly to hydrogen gas to effect hydrogen decrepitation of the rare earth magnet to produce a rare earth particulate material, and separating the rare earth particulate material from the rest of the assembly. The invention also resides in an apparatus for separating rare earth particulate material from an assembly comprising a rare earth magnet. The apparatus comprises a reaction vessel having an opening which can be closed to form a gas-tight seal, a separation means for separating the rare earth particulate material from the assembly, and a collection means for collecting the rare earth particulate material. The reaction vessel is connected to a vacuum pump and a gas control system, and the gas control system controls the supply of hydrogen gas to the reaction vessel.

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Dudley, United Kingdom

Allan Walton