Nd composite selective recovery from waste permanent magnet scrap powders by solid-fluorination reaction |
Yun-Ho Jin1,2, Hee-Seon Kim1, Jae-Kyo Yang1, Dae-Weon Kim1, Dong-Wan Kim2 |
1Center for Advanced Materials and Processing, Institute for Advanced Engineering, Yong In, 17180, South Korea 2School of Civil, Environmental, and Architectural Engineering, Korea University, Seoul, 02841, South Korea |
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Received: September 7, 2023; Revised: November 13, 2023 Accepted: November 21, 2023. Published online: December 14, 2023. |
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ABSTRACT |
This study proposes a novel waste permanent magnet (WPM) recycling technology by avoiding conventional technology that relies on strong acid and developing a feasible process using relatively inexpensive reagents, thereby reducing overall process cost to acceptable levels. Nd2Fe14B WPMs were transformed into a fluoride/oxide composite material through oxidation/fluorination heat treatment. The phase transition from FeF3-NdF3 to Fe2O3-NdF3 composition was performed via heat treatment. The Fe2O3-NdF3 composition is selectively leached using an oxalic acid. It was confirmed that Fe2O3 was selectively leached, and NdF3 was leached at less than 1 wt.% under various leaching conditions. The neodymium fluoride produced using this technology is expected to be applicable to related fields such as Nd smelting flux or catalysts, and this technology is expected to be applied to various materials containing Fe. |
Key words:
Permanent magnet · Phase transition · Oxalic acid · Selective leaching · Recovery |
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