Towards an Alloy Recycling of Nd–Fe–B Permanent Magnets in a Circular Economy
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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.
KeywordsNd–Fe–B Permanent magnet Rare earth recycling Hydrogen decrepitation Melt-spinning
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 was provided by Hessisches Ministerium für Wissenschaft und Kunst, Bundesministerium für Bildung und Forschung and Fraunhofer-Gesellschaft.
- 1.Kopacek B (2017) Mobile hydrometallurgy to recover rare and precious metals from weee. In: ERES 2017—book of abstracts, SantoriniGoogle Scholar
- 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.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.European Commission (2010) Critical raw materials for the EU. Report of the Ad hoc Working Group on defining critical raw materialsGoogle Scholar
- 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
- 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
- 10.Brown DN, Wu Z, He F, Miller DJ, Herchenroeder JW (2014) Dysprosium-free melt-spun permanent magnets. J Phys 26:064202Google Scholar
- 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
- 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.Krebs D (2017) Sustainable production of rare earths in greenland. In: ERES 2017—book of abstracts, SantoriniGoogle Scholar
- 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.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
- 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
- 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.Walton A, Williams A (2011) Rare earth recovery. Mater World 19:24–26Google Scholar
- 36.Coey J (ed) (1996) Rare-earth iron permanent magnets. OxfordGoogle Scholar
- 37.QYR NdFeB Research Center (2016) Global NdFeB market 2016: industry, analysis, research, share, growth, sales, trends, supply, forecast to 2021Google Scholar