McMaster University Researchers Review High Temp Recycling Strategies for Recovering Rare Earth Elements

Highlights

• Only 1% of magnets currently derive from recycled materials, highlighting the urgent need for advanced REE recycling technologies.
• Four major recycling approaches evaluated:
  • Hydrometallurgical methods
  • Electrochemical methods
  • Biometallurgical methods
  • Pyrometallurgical methods
• High-temperature processes show promising potential for recovering rare-earth elements from end-of-life magnets, despite ongoing challenges in energy consumption and scalability.

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Ali Zakeri (opens in a new tab) and Leili Tafaghodi, (opens in a new tab) both affiliated with the Department of Materials Science and Engineering at McMasters University in Canada, provide an in-depth review of high-temperature recycling strategies for recovering rare-earth elements (REEs) from magnet waste. Published in the Journal of Sustainable Metallurgy, the authors point out that as global demand for REEs intensifies, driven by their critical role in electronics, telecommunications, and clean energy, recycling has become an essential strategy to mitigate supply risks and reduce environmental impact.

Currently, only about 1% of all magnets are made of recycled materials.

The study evaluates key challenges in REE recycling, including low recovery rates, inefficient separation techniques, and the complexity of extracting REEs from diverse waste streams.  The Canada-based authors compare four major recycling approaches:

• Hydrometallurgical
• Electrochemical
• Biometallurgical
• Pyrometallurgical

They highlight their respective advantages and limitations. The focus, however, is on high-temperature processes such as oxidation-reduction reactions, flux extraction, collector slag systems, chlorination, liquid metal extraction, and molten salt electrolysis. These techniques offer promising efficiencies for recovering REEs from end-of-life magnets, but challenges such as energy consumption, secondary waste generation, and scalability remain.

The review underscores the urgent need for innovation in high-temperature recovery processes to enhance their economic viability and environmental sustainability. The authors call for further research into optimizing process conditions, improving selectivity in REE separation, and integrating advanced technologies to streamline recycling workflows.

As rare-earth dependence continues to grow, advancing these recycling methods will be critical in securing a more sustainable and resilient REE supply chain.