The outstanding properties of Nd-Fe-B magnets have positioned them as crucial components in various key technologies, including energy applications, wind turbine generators, motors for hybrid and electric vehicles, loudspeakers, and consumer electronics [1]. The ongoing expansion of e-mobility and renewable energies will drive an increased demand for these high-performance magnets [2]. However, the reliance on rare earths (RE) in their production presents challenges due to the critical nature of RE supply security and market dynamics. Moreover, the mining of the RE is associated with serious environmental problems and is also dominated by only a few suppliers outside Europe. Extensive research has been conducted to mitigate the dependency and supply risks associated with rare earth elements (REEs). This involves minimizing the use of heavy rare earths (HREs) on magnets [3] and implementing effective recycling methods for existing REEs obtained from industrial residues, pre-consumer scrap, and end-of-life products [4,5]. Despite these efforts, the practical application of these measures in industrial settings is still undergoing development.

Our study specifically targets the efficient functional recycling of high-performance Nd-Fe-B magnets sourced from diverse scrap magnet waste streams. Simultaneously, it aims to demonstrate to potential industries that primary magnets can be replaced in various applications by more sustainable recycled magnets without any performance losses. This substitution not only reduces costs and supply risks but also contributes to a more sustainable circular economy.

To achieve efficient functional recycling, Nd-Fe-B magnets sourced from diverse end-of-life products (such as electro-motors, wind turbines, and magnetic resonance imaging (MRI) magnets) along with production wastes were gathered, analysed, and recycled. In order to assess and showcase the potential applications of these recycled Nd-Fe-B magnets, various prototypes (including loudspeakers, organizer magnets, industrial motors, E-Scooter, lawn mower robots, cleaning robots, e-bikes, e-scooters and hoverboards) were investigated for their ease of dismantling and their magnetic property profiles.

The properties of the recycled magnets were compared (Figure 1) with the target values of the primary magnets that were removed from the devices subjected to investigation. The findings indicate that recycled magnets exhibit sufficient magnetic properties, making them viable substitutes for primary magnets in various applications. Through testing on different test benches, it was confirmed that installing recycled magnets (e.g., in e-bikes, e-scooters, and hoverboards) in these applications does not compromise the performance and indeed is perfectly feasible (Figure 2).