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Electrochemical behavior of Nd in its pyrometallurgical recovery from waste magnet

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Abstract

High-purity Nd metal was recovered from waste Nd–Fe–B magnet by the molten salt electrowinning process with chemical pretreatment. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), cyclic voltammetry (CV), chronopotentiometry (CP), and inductively coupled plasma-atomic emission spectrometer (ICP/AES) were used to characterize the deposit and electrochemical behaviors. The results show that NdF3 is effectively synthesized from the Nd–Fe–B magnet using HCl solution and NH4F. During the chemical treatment of the waste magnet, iron impurity is eliminated as a soluble [NH4]3[FeF6] complex. Electrowinning using NdF3 in LiF molten salt shows that Nd metal is deposited from the electrolyte on the cathode at the reduction potentials ranging from −1.48 to −1.35 V (vs. W) with the concentration change of NdF3. The final purity of Nd metal deposit is higher than 99.78 %.

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Acknowledgments

This work was financially supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) of the Korea Government Ministry of Knowledge Economy (No. 20122010300041) and the National Research Foundation of Korea (No. 2011-0091839).

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Authors and Affiliations

  1. Graduate School of Green Energy Technology, Chungnam National University, Daejeon, 305-764, Korea

    Hong-Youl Ryu & Jong-Hyeon Lee

  2. Department of NanoMaterials Engineering, Chungnam National University, Daejeon, 305-764, Korea

    Wan-Gou Kim

  3. Rapidly Solidified Materials Research Institute, Chungnam National University, Daejeon, 305-764, Korea

    Hayk H. Nersisyan

  4. Research Institute of Industrial Science and Technology, Pohang, 790-600, Korea

    Go-Gi Lee & Sung-Koo Jo

  5. Korea Research Institute of Chemical Technology, Daejeon, 305-600, Korea

    Huk-Hee Lee

  6. School of Energy Systems Engineering, Seoul National University, Seoul, 151-742, Korea

    Il-Soon Hwang

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  1. Hong-Youl Ryu
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Correspondence to Jong-Hyeon Lee.

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Ryu, HY., Lee, JH., Kim, WG. et al. Electrochemical behavior of Nd in its pyrometallurgical recovery from waste magnet. Rare Met. 34, 111–117 (2015). https://doi.org/10.1007/s12598-014-0241-3

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  • DOI: https://doi.org/10.1007/s12598-014-0241-3

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