Securing critical rare-earth supply through end-of-life NdFeB magnets recycling via molten salt electrolysis with consumable Mg-cathode

Recycling end-of-life (EoL) NdFeB magnets is critical for securing supply of rare-earth element neodymium in the low-carbon transition. We develop a molten salt electrolysis recycling approach using EoL NdFeB magnet anodes and a consumable solid magnesium cathode, operating at 548–650 °C and 0.75–3 A·cm−2 cathodic current density. Selective neodymium dissolution and in situ formation of a liquid Mg– (12.0–15.1 mol%) Nd alloy with average current efficiency of 98.4% are achieved. With high recycling efficiency and continuous operation, this approach overcomes neodymium collection and scalability barriers of conventional chloride electrolysis. Life-cycle assessment shows that the proposed process lowers climate change impacts to 17.36–18.18 kg CO2 eq. kg⁻¹ Nd, approximately 15% of that of primary production. Techno-economic analysis shows that neodymium metal production costs fall to 90.0 USD kg⁻¹ Nd at the 3000 A scale scenario, which is approximately one-third lower than the sales price of Nd metal. Such approach demonstrates significant potential for industrial-scale application and facilitates the integration of neodymium recycling into circular economy strategies. Molten-salt electrolysis with a consumable magnesium cathode recovers neodymium from end-of-life NdFeB magnets at high current efficiency, while life-cycle and economic analyses indicate potential for industrial-scale recycling.