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PhD topic Maximilain Ueberschaar
of recycling processes for the recovery of rare earth elements in
elements” (REE) is a group of single metals, which are related to
the third group in the chemical classification of elements and belong
to the lanthanides. Except of promethium, most of these REEs occur
contigued in nature (Rohstoff-Welt, 2012). REEs have unique
physical-chemical properties and are used therefore widely in many
electric and electronic equipment (EEE). They are indispensable for
information technology, telecommunication equipment, consumer
electronics in general and for appliances out of the renewable energy
The major part of the worldwide reserves of REE is located in China and in the former Soviet Union. Other areas with known deposits are Australia, USA, India and Canada. Although China holds only a third of the worldwide REE ores, it produces over 95% of the available quantities (Angerer et al., 2009). The dependence of consuming nations is therefore very high. The rising demand for REE worldwide and the restrictive export regulations of China exacerbate the upcoming supply problems (Röttger, 2011). Single elements like Neodymium, Praseodymium, Dysprosium, Terbium, Lanthanum, Yttrium and Europium are expected to be mostly affected. To keep the raw material supply in future stable, these elements have to be recycled to keep them available for further production processes. However, latest studies show-recycling rates for REE of under 1% (UNEP, 2011). Reasons are separation and sorting processes, which are not optimized on the recovery of REE. This thesis aims on the development of recycling processes to recover rare earth elements in WEEE.
Research approach and methodology
To achieve the research objectives, literature research and practical investigations are necessary. To obtain an overview on recycling processes in general and especially for the recovery of rare earth elements, literature knowledge and interviews with actors in the recycling sector form the basis for further investigations. A database set-up holds information about actually processed mass flows in recycling facilities and available techniques. Particular important mass flows will be investigated. Various separation systems will be compared as well as manual disassembly. Laboratory analysis show the potential of rare earth elements in investigated mass flows related to used treatment processes and therefore the losses with the actual recycling techniques. Further on, sorting processes will be evaluated. For this purpose in the recycling sector already used separation aggregates will be compared with systems out of other industry sectors (for example element detection with X-ray fluorescence analysis). The REE enriched mass flows will be chemically analyzed. Results will show the contents of rare earth metals and by-metals in practically producible material mixes. On this basis, subsequent enrichment process routes can be figured out.
Expected results and scientific importance
The results of the planned doctoral thesis create the basis for a successful recovery of rare earth elements in WEEE. It investigates the possibilities of particular separation and sorting technologies to concentrate REE in separate mass flows. This leads to a higher purity of other recycling products and to a more environmental friendly and sustainable closed loop management for REE. A precise economic assessment is not part of this thesis.
Rohstoff-Welt (2012) Seltene Erden. URL: www.rohstoff-welt.de/basiswissen/seltene-erden_rare-earth-elements.php ; 2012-01-23
Angerer, G. et al. (2009) Rohstoffe für Zukunftstechnologien. Karlsruhe; Deutschland: Fraunhofer IRB Verlag
Michelle Röttger (2011) China säubert Markt für seltene Erden. Financial Times Deutschland, Hamburg
UNEP, International Resource Panel (2011) Recycling Rates of Metals: A Status Report. Paris, Frankreich: UNEP DTIE Sustainable Consumption and Production Branch