The removal of the carbon from Nd-Fe-B magnet scraps is indispensable for
high-quality recycling by induction melting method as a preliminary process. The
decarburization under reduced pressure was developed by using the Nd-Fe-B magnet
grinding sludge that is highly contaminated with carbon and recycling has been
assumed to be difficult. The grinding sludge scrap was effectively decarburized
without generating an excessive iron oxide by heating under reduced pressure.
The decarburized powder was deoxidized by using the molten salts reduction with
Ca, which has large affinity with oxygen. Consequently, the decarburized powder
could be deoxidized even the level that can be melted industrially. In this
research, the preliminary process using the Nd magnet grinding sludge scraps
before induction melting is described.