Rare Earth Magnets Recycling: Study of a Safer and Cost-Effective Technique

Rare Earth magnets are currently adopted in different industrial sectors, from household utilities to automotive applications, informatics to sensors, etc. Rare Earth magnets show the best magnetic performance, predominantly in the case of Neodymium magnets, and help in reducing the weight/volume ratio. On the other hand, the instability of the raw material market should be considered together with the location of Rare Earth materials in a few areas of the planet, with an expensive extraction process. For these reasons, recycling Neodymium-Iron-Boron magnets is considered a necessary and promising solution. Different techniques are available, but they are generally expensive or rather dangerous. Some methods to recover NdFeB powder from various devices are based on Hydrogen, such as Hydrogen decrepitation or hydrometallurgical methods, and alternatively chemical processes. This work proposes a new method based on a mechanical technique without using Hydrogen, resulting in a safer, less complicated and cheaper process. Based on the vacuum impact mill, the mechanical process of grinding the magnets recovered from hard disk drives has been tested. The obtained powder shows NdFeB magnetic characteristics and can be used again to produce permanent magnets.