Highlights

• Hydrothermal leaching emerges as the most sustainable REE recovery method, with the lowest environmental impact of 8.8 kg CO₂-equivalent per kg of REE salt.
• Researchers project net positive cash flows of $41 million over a 13-year plant lifespan, demonstrating significant economic potential.
• Study provides crucial insights for investors and policymakers seeking circular supply chain solutions for rare earth element recycling.

A new peer-reviewed study published in ACS Sustainable Chemistry & Engineering offers compelling evidence that hydrothermal processing is the most sustainable and economically advantageous method for recovering rare earth elements (REEs) from NdFeB waste magnets—a key component of electric vehicle motors and wind turbines. Researchers compared four upstream processing strategies and found that hydrothermal leaching not only had the lowest environmental impact—emitting just 8.8 kg CO₂-equivalent per kg of REE salt—but also delivered the highest return on investment (187.1%) and a rapid payback period of just 0.8 years. In contrast, hydrogen decrepitation methods were found to be the least viable, with high electricity consumption and poor financial performance.

The findings could be a game-changer for rare earth recycling amid tightening global supply chains and rising geopolitical tensions. With projected net positive cash flows of $41 million over a 13-year plant lifespan, the study provides crucial guidance for investors and policymakers eyeing domestic and circular supply chain solutions. However, Rare Earth Exchanges (REEx) cautions that these results, while promising, are based on modeled scenarios. Industrial-scale validation, regulatory alignment, and strategic capital allocation will determine whether such recycling innovations can effectively displace reliance on Chinese upstream supply.

Source: Sharifian, S., Nili, S., & Vahidi, E. (2025). ACS Sustainable Chemistry & Engineering (opens in a new tab).