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Journal of Sustainable Metallurgy

, Volume 4, Issue 2, pp 163–175 | Cite as

Towards an Alloy Recycling of Nd–Fe–B Permanent Magnets in a Circular Economy

  • Oliver Diehl
  • Mario Schönfeldt
  • Eva Brouwer
  • Almut Dirks
  • Karsten Rachut
  • Jürgen Gassmann
  • Konrad Güth
  • Alexander Buckow
  • Roland Gauß
  • Rudolf Stauber
  • Oliver Gutfleisch
Innovations in WEEE Recycling

Abstract

Rare earth permanent magnets are an integral part of many electrical and electronic devices as well as numerous other applications, including emerging technologies like wind power, electric vehicles, fully automized industrial machines, and robots. Due to their outstanding properties, magnets based on Nd–Fe–B alloys are often not substitutable by employing less critical material systems. Today, WEEE (Waste Electrical and Electronic Equipment) take-back systems for a variety of products containing Nd–Fe–B magnets are well established. They form an ideal basis for a systematic provision of scrap magnets that can be recycled. Hydrometallurgical approaches that aim at completely dissolving the material to regain elements or oxides are energy and time consuming. Thus, they are costly and come with a large environmental footprint. Recycled rare earth elements and oxides would have to compete with virgin materials from China and can hardly be processed in Europe, due to the lack of respective industries. This paper presents material-to-material recycling approaches, which would maintain the magnet alloys and use them directly for a new magnet production loop. The recycled magnets compete well with those made from primary materials, that is, in terms of magnetic properties as well as in terms of production costs. They excel by far rare earth permanent magnets made from primary materials regarding the environmental footprint. Regarding the shift towards a Green Economy, humanity will consume less fuels in combustion processes but rather exploit functional materials in renewable energy and mobility technologies in the future. This shift fundamentally depends on a circular economy of noble as well as less-noble technology metals.

Keywords

Nd–Fe–B Permanent magnet Rare earth recycling Hydrogen decrepitation Melt-spinning 

Notes

Acknowledgements

The authors would like to thank the Federal Country Hessen for financial support in setting up the Fraunhofer Project Group IWKS. In addition, the authors are thankful to the German Ministry of Education and Research for financial support for project RECVAL-HPM (Innovative Reuse and Recycling Value Chain for High Power Magnets). The authors are grateful to the Fraunhofer Gesellschaft which supports this research by a major project: Lighthouse Project Criticality of Rare Earths. The authors thank David Kennedy for his support and discussion on the cost estimation.The authors also thank Siam Rummel and Konrad Opelt for their experimental assistance and discussion.

Funding

Funding was provided by Hessisches Ministerium für Wissenschaft und Kunst, Bundesministerium für Bildung und Forschung and Fraunhofer-Gesellschaft.

References

  1. 1.
    Kopacek B (2017) Mobile hydrometallurgy to recover rare and precious metals from weee. In: ERES 2017—book of abstracts, SantoriniGoogle Scholar
  2. 2.
    Deloitte, BGS, BRGM, TNO (2017) Directorate-general for internal market, industry, entrepreneurship and SMEs (European Commission). Study on the review of the list of Critical Raw Materials—final reportGoogle Scholar
  3. 3.
    European Commission (2014) On the review of the list of critical raw materials for the EU and the implementation of the Raw Materials Initiative. Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the RegionsGoogle Scholar
  4. 4.
    European Commission (2010) Critical raw materials for the EU. Report of the Ad hoc Working Group on defining critical raw materialsGoogle Scholar
  5. 5.
    Gutfleisch O, Willard MA, Brück E, Chen CH, Sankar SG, Liu JP (2011) Magnetic materials and devices for the 21st century: stronger, lighter, and more energy efficient. Adv Mater 23:821–842CrossRefGoogle Scholar
  6. 6.
    US Magnet Materials Association (2010) The US magnet materials story: past-present-future. http://www.usmagneticmaterials.com/documents/usmma-presentation-general-5-08.ppt. Accessed 06 May 2015
  7. 7.
    Alonso E, Sherman AM, Wallington TJ, Everson MP, Field FR, Roth R, Kirchhain RE (2012) Evaluating rare earth element availability: a case with revolutionary demand from clean technologies. Environ Sci Technol 46:3406–3414CrossRefGoogle Scholar
  8. 8.
    Shaw S, Constantinides S (2012) Permanent magnets: the demand for rare earths. In: 8th international rare earths conference, Innovation Metals Corp, Hong Kong, 13–15 Nov 2012Google Scholar
  9. 9.
    Sagawa M, Fujimura S, Togawa N, Yamamoto H, Matsuura Y (1984) New material for permanent magnets on a base of Nd and Fe (invited). J Appl Phys 55:2083–2087CrossRefGoogle Scholar
  10. 10.
    Brown DN, Wu Z, He F, Miller DJ, Herchenroeder JW (2014) Dysprosium-free melt-spun permanent magnets. J Phys 26:064202Google Scholar
  11. 11.
    Poenaru I, Lixandru A, Güth K, Gauß R, Gutfleisch O (2017) Light rare-earths substitution in rapidly solidified Nd2Fe14B-based alloys for resource-efficient permanent magnets fabrication. In: ERES2017: 2nd European rare earth resources conference, SantoriniGoogle Scholar
  12. 12.
    Pathak AK, Khan M, Gschneidner KA Jr, McCallum RW, Zhou L, Sun K, Dennis KW, Zhou C, Pinkerton FE, Kramer MJ, Pecharsky VK (2015) Cerium: an unlikely replacement of dysprosium in high performance Nd-Fe-B permanent magnets. Adv Mater 27(16):2663–2667CrossRefGoogle Scholar
  13. 13.
    Binnemans K, Jones PT, Van Acker K, Blanpain B, Mishra B, Apelian D (2013) Rare earth economics: the balance problem. JOM 65(7):846–848CrossRefGoogle Scholar
  14. 14.
    Topf A (2017) http://www.mining.com/. Accessed 16 June 2017. http://www.mining.com/mountain-pass-sells-20-5-million/. Accessed 19 July 2017
  15. 15.
    Krebs D (2017) Sustainable production of rare earths in greenland. In: ERES 2017—book of abstracts, SantoriniGoogle Scholar
  16. 16.
    Pellegrini M, Godlewska L, Millet P, Gislev M, Grasser L (2017) EU potential in the field of rare earth elements and policy actions. In: ERES 2017—book of abstracts, SantoriniGoogle Scholar
  17. 17.
    Kooroshy J, Tiess G, Tukker A, Walton A (eds) (2015) ERECON, strengthening the European rare earth supply chain: challenges and policy options. http://www.mawi.tu-darmstadt.de/media/fm/homepage/news_seite/ERECON_Report_v05.pdf. Accessed 28 May 2015
  18. 18.
    Binnemans K, Jones PT (2015) Rare earths and the balance problem. J Sustain Metall 1(1):29–38CrossRefGoogle Scholar
  19. 19.
    Gauß R, Gutfleisch O (2016) Magnetische Materialien—Schlüsselkomponenten für neue Energietechnologien. In: Rohstoffwirtschaft und gesellschaftliche Entwicklung. Die nächsten 50 Jahre. Springer, Berlin, pp 99–118Google Scholar
  20. 20.
    Yang Y, Walton A, Sheridan R, Güth K, Gauß R, Gutfleisch O, Buchert M, Steenari B-M, Van Gerven T, Jones PT, Binnemans K (2017) REE recovery from end-of-life NdFeB permanent magnet scrap: a critical review. J Sustain Metall 3:122–149CrossRefGoogle Scholar
  21. 21.
    Binnemans K, Jones PT, Blanpain B, Van Gerven T, Yang Y, Walton A, Buchert M (2013) Recycling of rare earths: a critical review. J Clean Prod 51:1–22CrossRefGoogle Scholar
  22. 22.
    Yoon H-S, Kim C-J, Chung K-W, Kim S-D (2016) Solvent extraction, separation and recovery of dysprosium (Dy) and neodymium (Nd) from aqueous solutions: waste recycling strategies for permanent magnet processing. Hydrometallurgy 165:27–43CrossRefGoogle Scholar
  23. 23.
    Bast U, Blank R, Buchert M, Elwert T, Finsterwalder F, Hörnig G, Klier T, Langkau S, Marscheider-Weidemann F, Müller J-O, Thürigen C, Treffer F, Walter T (2014) Recycling von Komponenten und strategischen Metallen aus elektrischen Fahrantrieben. http://www.ifa.tu-clausthal.de/fileadmin/Aufbereitung/Dokumente_News_ETC/MORE_Abschlussbericht.pdf
  24. 24.
    Walton A, Williams A (2011) Rare earth recovery. Mater World 19:24–26Google Scholar
  25. 25.
    Walton A, Yi H, Rowson NA, Speight JD, Mann VSJ, Sheridan RS, Bradshaw A, Harris IR, Williams AJ (2015) The use of hydrogen to separate and recycle neodymium-iron-boron-type magnets from electronic waste. J Clean Prod 104:236–241CrossRefGoogle Scholar
  26. 26.
    Herbst JF (1991) Neodymium-iron-boron permanent magnets. J Magn Magn Mater 100:57–78CrossRefGoogle Scholar
  27. 27.
    Gutfleisch O (2000) Controlling the properties of high energy density permanent magnetic materials by different processing routes. J Phys D 33:R157–R172CrossRefGoogle Scholar
  28. 28.
    Gauß R, Diehl O, Brouwer E, Buckow A, Güth K, Gutfleisch O (2015) Verfahren zum Recycling von seltenerdhaltigen Permanentmagneten. Chem Ing Tec 87(11):1477–1485CrossRefGoogle Scholar
  29. 29.
    Zakotnik M, Devlin E, Harris IR, Williams AJ (2006) Hydrogen decrepitation and recycling of NdFeB-type sintered magnets. J Iron Steel Res Int 13(1):289–295CrossRefGoogle Scholar
  30. 30.
    Zakotnik M, Harris I, Williams A (2009) Multiple recycling of NdFeB-type sintered magnets. J Alloys Compd 469:314–321CrossRefGoogle Scholar
  31. 31.
    Liu W, Li C, Zakotnik M, Yue M, Zhang D, Huang X (2015) Recycling of waste Nd-Fe-B sintered magnets by doping with dysproisum hydride nanoparticles. J Rare Earths 33(8):846–849CrossRefGoogle Scholar
  32. 32.
    Hirota K, Nakamura H, Minowa T, Honshima M (2006) Coercivity enhancement by the grain boundary diffusion process to Nd-Fe-B sintered magnets. IEEE Trans Magn 42(10):2909–2911CrossRefGoogle Scholar
  33. 33.
    Zakotnik M, Tudor C (2015) Commercial-scale recycling of NdFeB-type magnets with grain boundary modification yields products with ‘designer properties’ that exceed those of starting materials. Waste Manag 44:48–54CrossRefGoogle Scholar
  34. 34.
    Kirchner A, Hinz D, Panchnathan V, Gutfleisch O, Müller KH, Schultz L (2000) Improved hot workability and magnetic properties in NdFeCoGaB hot deformed magnets. IEEE Trans Magn 36(5):3288–3290CrossRefGoogle Scholar
  35. 35.
    Brown DN, Smith B, Ma BM, Campbell P (2004) The dependence of magnetic properties and hot workability of rare earth-iron-boride magnets upon composition. IEEE Trans Magn 40(4):2895–2897CrossRefGoogle Scholar
  36. 36.
    Coey J (ed) (1996) Rare-earth iron permanent magnets. OxfordGoogle Scholar
  37. 37.
    QYR NdFeB Research Center (2016) Global NdFeB market 2016: industry, analysis, research, share, growth, sales, trends, supply, forecast to 2021Google Scholar
  38. 38.
    Zakotnik M, Tudor C, Peiró L, Afiuny P, Skomski R, Hatch G (2016) Analysis of energy usage in Nd–Fe–B magnet to magnet. Environ Technol Innov 5:117–126CrossRefGoogle Scholar
  39. 39.
    Sprecher B, Xiao Y, Walton A, Speight J, Harris R, Kleijn R, Kramer G, Visser G (2014) Life cycle inventory of the production of rare earths and the subsequent production of NdFeB rare earth permanent magnets. Environ Sci Technol 48(7):3951–3958CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2018

Authors and Affiliations

  • Oliver Diehl
    • 1
  • Mario Schönfeldt
    • 1
  • Eva Brouwer
    • 1
  • Almut Dirks
    • 1
  • Karsten Rachut
    • 1
  • Jürgen Gassmann
    • 1
  • Konrad Güth
    • 1
  • Alexander Buckow
    • 1
  • Roland Gauß
    • 2
    • 1
  • Rudolf Stauber
    • 1
  • Oliver Gutfleisch
    • 1
    • 3
  1. 1.Fraunhofer ISC, Project Group Materials Recycling and Resource Strategies IWKSHanauGermany
  2. 2.EIT RawMaterials GmbHBerlinGermany
  3. 3.Technische Universität Darmstadt, Materials ScienceDarmstadtGermany

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