Materials Transactions Online

Materials Transactions, Vol.58 No.03 (2017) pp.400-405
© 2017 The Japan Institute of Metals and Materials

Electrochemical Recovery of Rare Earth Elements from Magnets: Conversion of Rare Earth Based Metals into Rare Earth Fluorides in Molten Salts

Aida Abbasalizadeh1, Annelies Malfliet2, Seshadri Seetharaman3, Jilt Sietsma1 and Yongxiang Yang1

1Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628CD, Delft, The Netherlands
2Department of Materials Engineering, Kasteelpark Arenberg 44 - bus 2450, BE-3000 Leuven, Belgium
3Royal Institute of Technology (KTH), Sweden

In the present work, selective extraction of rare earth (RE) metals from NdFeB magnets is investigated by studying the effects of various fluxes, viz. AlF3, ZnF2, FeF3 and Na3AlF6 in the LiF-NdFeB system. The aim is to convert RE from RE magnet into the fluoride salt melt. The results show the complete selective separation of neodymium (also dysprosium) from the magnet and formation of rare earth fluoride, leaving iron and boron unreacted. The formed rare earth fluoride can subsequently be processed in the same reactor through an electrolysis route so that RE can be deposited as a cathode product. The results of XRD and EPMA analysis of the reacted samples indicate that AlF3, ZnF2 and FeF3 can act as strong fluorinating agents for extraction of rare earth from NdFeB magnet, converting the RE to REF3.

The results confirm the feasibility of the rare earth metals recovery from scrap NdFeB magnet as raw material. The fluoride conversion-electrolysis route suggested in the present work enables the extraction of rare earth metals in a single step using the above-mentioned fluxes.

[doi:10.2320/matertrans.MK201617]

(Received 2016/09/01; Accepted 2016/12/19; Published 2017/02/25)

Keywords: rare earth, recycling, rare earth magnet, fluorination

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REFERENCES

  1. K. Binnemans, P.T. Jones, B. Blanpain, T. Van Gerven, Y. Yang, A. Walton and M. Buchert: J. Clean. Prod. 51 (2013) 1-22.
  2. O. Takeda, T.H. Okabe and Y. Umetsu: J. Alloy. Compd. 408-412 (2006) 387-390.
  3. Y. Bian, S. Guo, L. Jiang, J. Liu, K. Tang and W. Ding: ACS Sustainable Chemistry & Engineering 4 (2016) 810-818.
  4. T. Nohira, S. Kobayashi, K. Kobayashi, R. Hagiwara, T. Oishi and H. Konishi: ECS Trans. 33 (2010) 205-212.
  5. A.M. Martinez, O. Kjos, E. Skybakmoen, A.r. Solheim and G.M. Haarberg: ECS Trans. 50 (2013) 453-461.
  6. S. Riaño and K. Binnemans: Green Chem. 17 (2015) 2931-2942.
  7. H.D. Bandara, K.D. Field and M.H. Emmert: Green Chem. 18 (2016) 753-759.
  8. B. Mishra and D.L. Olson: J. Phys. Chem. Solids 66 (2005) 396-401.
  9. W. Han, Q. Chen, Y. Sun, T. Jiang and M. Zhang: Metall. Mater. Trans., B 42 (2011) 1367-1375.
  10. Y. Castrillejo, M.R. Bermejo, P. Díaz Arocas, A.M. Martínez and E. Barrado: J. Electroanal. Chem. 575 (2005) 61-74.
  11. P. Taxil, L. Massot, C. Nourry, M. Gibilaro, P. Chamelot and L. Cassayre: J. Fluor. Chem. 130 (2009) 94-101.
  12. S. Seetharaman, O. Grinder: US patent application nr. 12/991128, ref. no.: 12057 (2010).
  13. A. Abbasalizadeh, S. Seetharaman, L. Teng, S. Sridhar, O. Grinder, Y. Izumi and M. Barati: Journal Of Materials 65 (2013) 1552-1558.
  14. T.H. Okabe, S. Shirayama: Method and apparatus for recovery of rare earth element, US8323592 B2 (2012).
  15. A. Abbasalizadeh, L. Teng, S. Sridhar and S. Seetharaman: Mineral Processing and Extractive Metallurgy 124 (2015) 191-198.
  16. T. Uda: Mater. Trans. 43 (2002) 55-62.


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