Liquid Metal Leaching for Rare Earth Magnet Recycling–Startup Seeks to Disrupt the Industry

Highlights

• Researchers develop advanced method to recover rare earth elements from NdFeB magnets using liquid magnesium with up to 80% efficiency.
• Innovative process reduces impurities through strategic leaching techniques, including mechanical stirring and pre-leaching demagnetization.
• Study demonstrates potential for cost-effective and sustainable recycling of critical materials used in electric vehicles, wind turbines, and electronics.

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A recent study published in the journal Metals (opens in a new tab) investigates the optimization of recycling rare earth elements (REEs) like neodymium (Nd) and praseodymium (Pr) from NdFeB magnets using liquid magnesium (Mg). These magnets are essential for modern technologies such as electric vehicles, wind turbines, and electronics. The study focuses on three key factors: leaching time, stirring, and magnet demagnetization, to improve recycling efficiency and reduce impurities.

The study was led by Associate Professor Adam Powell (opens in a new tab),  Emmanuel Opoku, MS (opens in a new tab) and colleagues at Worcester Polytechnic Institute finding first and foremost prolonged leaching (up to 5 hours at 900 °C) significantly enhances the recovery of Nd and Pr. Recovery peaked at 5 hours, with higher concentrations of REEs extracted into the Mg alloy.

Note below some of these inventors are founders of a company seeking to exploit this technology. They may be looking for investors.

Also importantly, mechanical stirring during the leaching process improved the homogeneity of REE distribution and increased recovery rates, achieving up to 80% efficiency. Stirring minimized the accumulation of REEs at the bottom of the alloy, ensuring a more even mix.

Finally, pre-leaching demagnetization reduced the co-extraction of nickel and copper impurities by over 80%. This step likely altered the magnet’s surface properties, improving selectivity for REEs and reducing contamination.

So, what are the implications?  Rare Earth Exchanges provides a breakdown of this study.

Implications	Summary
Cost-Effective Recycling	The process minimizes the energy and cost typically associated with traditional methods like oxide separation and reduction.
Environmental Impact	By recovering REEs from waste magnets, this method reduces reliance on mining, supporting sustainable resource management.
Technological Relevance	Improved recovery techniques align with the growing demand for REEs in clean energy and high-tech industries.

Recommendations:

The academic researchers suggest more investigation exploring alternative surface passivation methods to further enhance selectivity, such as sulfidation or fluoridation. Additionally, integrating efficient stirring mechanisms and optimizing leaching durations can further improve scalability for industrial applications.

Other authors include Chinenye Chinwego and Brajendra Mishra.

The Venture

Authors Chinenye Chinwego and Adam Powell are the co-founders and part owners of Excava LLC (opens in a new tab) whose goal is to commercialize the rare earth magnet recycling process described herein. Author Adam Powell is the lead inventor of U.S. Patent 11,773,500 on the G-METS distillation of metals which is a part of the rare earth magnet recycling process flowsheet shown in Figure 2 (opens in a new tab) (though it does not play a role in this leaching study).