Comparison of Different Leaching Media and Their Effect on REEs Recovery from Spent Nd-Fe-B Magnets

Loading...
Thumbnail Image
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
This publication is imported from Aalto University research portal.
View publication in the Research portal
View/Open full text file from the Research portal
Date
2020-02-01
Major/Subject
Mcode
Degree programme
Language
en
Pages
10
806-815
Series
JOM, Volume 72, issue 2
Abstract
Recycling rare-earth elements (REEs) from Nd-Fe-B magnet waste is an important step towards building a sustainable REE supply chain. In this study, two different processes were systematically investigated and compared. In the leaching stage, the effect of increasing H2SO4 or HCl concentrations were studied and it was determined that, although both can successfully promote REEs, B, Fe and Co leaching, HCl solutions extracted a wider range of metals. After leaching, the oxalate and double-sulfate precipitation methods were utilized to separate REEs from either HCl or H2SO4 leachates. Results suggest that, although > 99% REEs precipitation rates could be achieved with oxalate, the purity of REE-containing products is significantly affected by impurities like Fe and Co. In contrast, REE double-sulfate precipitation resulted in a product purity of > 99%; however, high levels of Na2SO4 (8 times the stoichiometric amount) were needed to achieve > 98% of REE precipitation.
Description
Keywords
HIGH-TEMPERATURE OXIDATION, COBALT OXIDES, ACID, DISSOLUTION, MECHANISMS, REDUCTION, KINETICS, SCRAP, IRON
Other note
Citation
Liu , F , Porvali , A , Halli , P , Wilson , B P & Lundstrom , M 2020 , ' Comparison of Different Leaching Media and Their Effect on REEs Recovery from Spent Nd-Fe-B Magnets ' , JOM , vol. 72 , no. 2 , pp. 806-815 . https://doi.org/10.1007/s11837-019-03844-7