Recycling of Nd-Fe-B Magnets from Scrap Hard Disc Drives

Abstract:

A hydrogen-based treatment, including Hydrogen Decrepitation (HD) and Hydrogen Disproportionation-Desorption-Recombination (HDDR), was used as part of a recycling procedure for scrap neodymium-iron-boron magnets. Chemical methods of removing nickel coating out of magnets were tested, however ineffectively. Powders were obtained from magnets after the HD and were further processed by the HDDR. Finally, material with maximum energy product (BH)_max of 74 kJ/m³ was produced. Chemical composition of magnets (MS, EDS), magnetic properties (VSM) and microstructure observations (SEM) were carried out.

• Periodical: Key Engineering Materials (Volume 682)
• Pages: 308-313
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.682.308
• Online since: February 2016
• Authors: Mateusz Szymański*, Bartosz Michalski, Marcin Leonowicz, Zbigniew Miazga
• Keywords: Critical Metals, HDDR, Magnets, Rare Earths, Recycling

References

[1] K. Binnemans, P.T. Jones, B. Blanpain, T. Van Gerven, Y. Yang, A. Walton, M. Buchert, Recycling of rare earths: a critical review, J. Clean. Prod. 51, (2013) 1-22.

DOI: 10.1016/j.jclepro.2012.12.037

[2] S. Massari, M. Ruberti, Rare earth elements as critical raw materials: Focus on international markets and future strategies, Resour. Policy, 38, (2013) 36-43.

DOI: 10.1016/j.resourpol.2012.07.001

[3] Information on http: /www. parliament. uk/documents/post/postpn368rare_earth_metals. pdf.

[4] M. Schluep, Ch. Hagelueken, R. Kuehr, F. Magalini, C. Maurer, Ch. Meskers, E. Mueller, F. Wang, Recycling From E-Waste To Resources - United Nations Environment Programme, Oktoberdruck AG, Berlin, (2009).

[5] M.A. Hudson, C. van Schaik, A. Heiskanen, K. Meskers, C. Hagelüken, UNEP Metal Recycling: Opportunities, Limits, Infrastructure, A Report of the Working Group on the Global Metal Flows to the International Resource Panel, Reuter, (2013).

[6] A. Walton, A.I. Bevan, V.S.J. Mann, J.D. Speight, I.R. Harris, A.J. Williams, H. Yi, The Use of Hydrogen to Separate and Recycle NdFeB Magnets from Electronic Waste, Proceedings of the 22nd International Workshop on Rare-Earth Permanent Magnets and their Applications 2012, 10-13.

DOI: 10.1016/j.jclepro.2015.05.033

[7] K. Güth, T.G. Woodcock, L. Schultz, O. Gutfleisch, Recycling of sintered Nd-Fe-B magnets by the d-HDDR route, Proceedings of the 22nd International Workshop on Rare-Earth Permanent Magnets and their Applications 2012, 14-17.

DOI: 10.1002/aenm.201200337

[8] B.F.A. da Silva, S.R. Janasi, H. Takiishi, D. Rodrigues, M.F. de Campos, Hybrid Bonded Rare-Earth Magnets Produced with Strontium Ferrite and Recycled NdFeB Powders, Proceedings of the 22nd International Workshop on Rare-Earth Permanent Magnets and their Applications 2012, 322-325.

[9] E.A. Périgo, S.C. da Silva, R.V. Martin, H. Takiishi, F.J.G. Landgraf, Properties of hydrogenation-disproportionation-desorption-recombination NdFeB powders prepared from recycled sintered magnets, J. Appl. Phys. 111 (2012), 07A725.

DOI: 10.1063/1.3677761

[10] G.C. Hadjipanayis, Bonded Magnets, Proceedings of the NATO Advanced Research Workshop on Science and Technology of bonded magnets. Springer, Netherlands, (2003).

[11] G. Herzer, Grain size dependence of coercivity and permeability in nanocrystalline ferromagnets, IEEE Trans. Magn. 26, (1990), 1397-1402.

DOI: 10.1109/20.104389

[12] S. Sugimoto, D. Book, HDDR Process for the Production of High Performance Rare-Earth Magnets, in: Yi Liu, D.J. Sellmyer, D. Shindo (Eds. ), Handbook of Advanced Magnetic Materials, Springer US, 2006, pp.977-1007.

DOI: 10.1007/1-4020-7984-2_23

[13] R.S. Sheridan, A.J. Williams, I.R. Harris, A. Walton, Improved HDDR processing route for production of anisotropic powder from sintered NdFeB type magnets, J. Magn. Magn. Mater. 350, (2014) 114-118.

DOI: 10.1016/j.jmmm.2013.09.042

[14] P. J. McGuiness, I. R. Harris, E. Rozendaal, J. Ormerod, M. Ward, The production of a Nd-Fe-B permanent magnet by a hydrogen decrepitation/attritor milling route, J. Mater. Sci. 21 (1986), 4107-4110.

DOI: 10.1007/bf02431659

[15] H.K. Jun, I. I. Yaacob, Investigation of Particle Size Effects on the Magnetic Properties and Corrosion Behaviour of Mechanically Alloyed Nd-Fe-B Powder, Key Eng. Mat. 306-308 (2006), 971-976.

DOI: 10.4028/www.scientific.net/kem.306-308.971

[16] Information on http: /www. enesmagnets. pl.

[17] Information on http: /www. magfine. com/what-is-magfine.