A holistic approach for the recovery of rare earth elements and scandium from secondary sources under a circular economy framework – A review

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Yüksekdağ A., Köse Mutlu B., Siddiqui A. F., Wiesner M. R., Koyuncu İ.

Chemosphere, vol.293, 2022 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Review
  • Volume: 293
  • Publication Date: 2022
  • Doi Number: 10.1016/j.chemosphere.2022.133620
  • Journal Name: Chemosphere
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Aqualine, Aquatic Science & Fisheries Abstracts (ASFA), Artic & Antarctic Regions, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, EMBASE, Environment Index, Food Science & Technology Abstracts, Geobase, Greenfile, MEDLINE, Metadex, Pollution Abstracts, Public Affairs Index, Veterinary Science Database, Civil Engineering Abstracts
  • Keywords: Circular economy, Secondary sources, Rare earth elements, Scandium, Sustainability, Pilot-scale recovery
  • Istanbul Technical University Affiliated: Yes


© 2022 Elsevier LtdLimited natural resources and a continuous increase in the demand for modern technological products, is creating a demand and supply gap for rare earth elements (REEs) and Sc. There is therefore a need to adopt the sustainable approach of the circular economy system (CE). In this review, we defined six steps required to close the loop and recover REEs, using a holistic approach. Recent statistics on REEs and Sc demand and the number of waste generations are reported and studies on more environmentally friendly, economic, and/or efficient recovery processes are summarized. Pilot-scale recovery facilities are described for several types of secondary sources. Finally, we identify obstacles to closing the REE loop in a circular economy and the reasons why secondary sources are not preferred over primary sources. Briefly, recovery from secondary sources should be environmentally and economically friendly and of an acceptable standard concerning final product quality. However, current technologies for recovery from for secondary sources are limiting and technology needs will vary depending on the source type. The quality/purity of the recovered metals should be proven so that they do not result in any adverse effects on the product quality, when they are being used as secondary raw material. In addition, for industrial-scale facilities, process improvements are required that consider environmental conditions.