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Revolutionizing Rare Earth Recycling: A Study on Neodymium Recovery from Hard Disk Drives

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Highlights

  • Researchers at IMNR developed a novel microwave-assisted liquid metal extraction method to recover neodymium from spent hard disk drive magnets.
  • The process achieved a 97% recovery rate with 95-98% purity.
  • Magnesium was used as an extractant in the process, along with vacuum distillation.
  • The study represents a promising step towards sustainable rare earth element recycling.
  • Industrial scalability remains a future challenge.

A team of researchers led by Sabina Andreea Fironda from the National Research and Development Institute for Non-Ferrous and Rare Metals (IMNR) in Romania has developed a novel method to extract neodymium (Nd) from spent hard disk drive magnets using microwave-assisted liquid metal extraction (LME). This innovative approach aims to improve the sustainability of rare earth element (REE) recycling, reducing dependence on environmentally harmful mining.

The Study

Published in Magnetism (opens in a new tab), the study hypothesized that microwave heating could enhance LME efficiency, making neodymium recovery from end-of-life NdFeB magnets both feasible and scalable. Researchers conducted a controlled experimental study using magnesium (Mg) as an extractant, followed by vacuum distillation to separate Nd from the Mg-Nd alloy.

The process involved heating crushed HDD magnet scrap (2-5 mm) in a microwave furnace at 800-900°C for up to 8 hours, achieving a 97% recovery rate. The Nd sponge obtained contained 95-98 wt.% purity, demonstrating the method’s effectiveness. The study found that increasing temperature and holding time significantly improved extraction efficiency, confirming that microwave-assisted LME could be an efficient alternative to conventional REE recycling methods.

Always Mind the Details

Despite its promise, the study has several limitations. The prototype microwave system lacked full temperature and pressure control, which may impact reproducibility on an industrial scale. Additionally, while magnesium recycling in this process is possible, energy consumption remains high, and scalability challenges must be addressed. The method also focuses primarily on Nd recovery, whereas other valuable REEs in HDD magnets (such as Dy, Pr, and Tb) remain underexplored.

What Implications?

This research has significant implications for the circular economy and supply chain security of rare earth elements (REEs). As demand for REEs surges due to their critical role in electric vehicles, wind turbines, and advanced electronics, scalable and environmentally friendly recycling methods will be essential. By proving that microwave-assisted LME can efficiently extract neodymium, this study lays the groundwork for further development in sustainable REE recovery, potentially reducing reliance on primary mining and mitigating supply chain risks.

But make no mistake, we are at least a decade away from the use of recycling for REE at scale, and we are highly dependent on the People’s Republic of China.

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