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High-Gradient Magnetic Separation of Compact Fluorescent Lamp Phosphors: Elucidation of the Removal Dynamics in a Rotary Permanent Magnet Separator

Boelens, Peter; Lei, Zhe; Drobot, Björn; Rudolph, Martin; Li, Zichao; Franzreb, Matthias ORCID iD icon; Eckert, Kerstin; Lederer, Franziska


In an ongoing effort towards a more sustainable rare-earth element market, there is a high potential for an efficient recycling of rare-earth elements from end-of-life compact fluorescent lamps by physical separation of the individual phosphors. In this study, we investigate the separation of five fluorescent lamp particles by high-gradient magnetic separation in a rotary permanent magnet separator. We thoroughly characterize the phosphors by ICP-MS, laser diffraction analysis, gas displacement pycnometry, surface area analysis, SQUID-VSM, and Time-Resolved Laser-Induced Fluorescence Spectroscopy. We present a fast and reliable quantification method for mixtures of the investigated phosphors, based on a combination of Time-Resolved Laser-Induced Fluorescence Spectroscopy and parallel factor analysis. With this method, we were able to monitor each phosphors’ removal dynamics in the high-gradient magnetic separator and we estimate that the particles’ removal efficiencies are proportional to (d$^{2}$·χ)$^{1/3}$. Finally, we have found that the removed phosphors can readily be recovered easily from the separation cell by backwashing with an intermittent air–water flow. ... mehr

Verlagsausgabe §
DOI: 10.5445/IR/1000141446
Veröffentlicht am 21.12.2021
DOI: 10.3390/min11101116
Zitationen: 5
Web of Science
Zitationen: 4
Zitationen: 4
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Funktionelle Grenzflächen (IFG)
Publikationstyp Zeitschriftenaufsatz
Publikationsjahr 2021
Sprache Englisch
Identifikator ISSN: 2075-163X
KITopen-ID: 1000141446
HGF-Programm 43.33.11 (POF IV, LK 01) Adaptive and Bioinstructive Materials Systems
Erschienen in Minerals
Verlag MDPI
Band 11
Heft 10
Seiten Art. Nr.: 1116
Vorab online veröffentlicht am 12.10.2021
Schlagwörter rare-earth elements; compact fluorescent lamp phosphors; time-resolved laser-induced fluorescence spectroscopy; PARAFAC; rotary permanent magnet separator; high-gradient magnetic separation; kelvin force
Nachgewiesen in Dimensions
Web of Science
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