Turning Nd‐Fe‐B Swarf Into High‐Value Bulk Feedstocks via Sustainable Hydrogen Plasma: From Rare‐Earth Oxides to Metals and Hydrides

Abstract

ABSTRACT Rare‐earth permanent magnets (REPMs) are crucial for electric vehicles, wind turbines, and other high‐efficiency electric motor systems. However, their production is energy‐intensive, and global recycling rates are below 0.2%. Machining swarf is the main industrial waste from REPMs production. Despite its high rare‐earth elements (REEs) content (∼20 wt.%), it has received limited attention for sustainable recycling. We introduce hydrogen plasma reduction (HPR) as a new environmentally friendly method to recover REEs from REPM swarf. By tuning the hydrogen content and treatment time, we achieve phase separation into metallic Fe and a Nd 2 O 3 ‐rich rare‐earth fraction, providing a concentrated intermediate for subsequent REPM production. The process also enables direct rare‐earth hydride formation, confirming the plasma‐assisted partial rare‐earth metallization in the molten state. This procedure turns REPM swarf into separated, high‐value, high‐purity feedstock in a single, acid‐free step. Against the ∼70 kg CO 2 ‐eq kg −1 footprint of conventional REPM production, this recycling route offers a pathway toward substantially lower‐emission magnet production while reducing reliance on primary REE supply.