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Materials Science and Nanotechnology Engineering Department, Faculty of Engineering, Yeditepe University , Istanbul , Turkey
Materials Science and Nanotechnology Engineering Department, Faculty of Engineering, Yeditepe University , Istanbul , Turkey
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Materials Science and Nanotechnology Engineering Department, Faculty of Engineering, Yeditepe University , Istanbul , Turkey
Materials Science and Nanotechnology Engineering Department, Faculty of Engineering, Yeditepe University , Istanbul , Turkey
NdFeB (Neodymium-Iron-Boron) magnets are essential for technologies such as electric vehicles, wind turbines, and medical devices due to their high energy density. However, the growing demand for these magnets, coupled with the limited availability of rare earth elements (REEs), emphasizes the need for efficient recycling of end-of-life (EOL) NdFeB magnets to ensure long-term sustainability. A key step in the recycling process is demagnetization, which enables effective dismantling, sorting, and material recovery. Although demagnetization is typically performed at temperatures above the Curie temperature (300–400°C, depending on the magnet composition), limited studies have focused on optimizing this process for metallurgical recycling.
This study investigates the demagnetization behavior of EOL NdFeB magnets at 250°C, 300°C, and 350°C for durations of 20, 30, and 40 minutes in an open-atmosphere muffle furnace. The results show that complete demagnetization occurs at 300°C after a minimum of 30 minutes, whereas samples treated at 250°C remain magnetic, regardless of duration. At 350°C, full demagnetization was achieved at all tested time intervals. These results align with previous research indicating that effective demagnetization temperatures typically range between 350°C and 450°C. However, this study demonstrates that lower temperatures (300°C) can also lead to complete demagnetization under controlled conditions.
These findings highlight the potential to optimize the demagnetization step in the recycling process, contributing to more efficient hydro- and pyrometallurgical methods for rare earth element recovery. By reducing the temperature required for demagnetization, energy consumption is minimized, improving the cost-effectiveness and sustainability of NdFeB recycling. This advancement supports the development of more sustainable rare earth element recovery processes and contributes to circular economy efforts.
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