Rare earth recovery from end-of-life motors employing green chemistry design principles

2016 ◽  
Vol 18 (3) ◽  
pp. 753-759 ◽  
Author(s):  
H. M. Dhammika Bandara ◽  
Kathleen D. Field ◽  
Marion H. Emmert

This manuscript describes the development of an efficient process for the recovery of rare earth elements from materials mixtures such as in motors with a recovery rate of >80%. Selective dissolution enables efficient separation of steel and copper and selective precipitation of RE salts is the key for obtaining pure RE products.

2019 ◽  
Vol 236 ◽  
pp. 117573 ◽  
Author(s):  
Linda Omodara ◽  
Satu Pitkäaho ◽  
Esa-Matti Turpeinen ◽  
Paula Saavalainen ◽  
Kati Oravisjärvi ◽  
...  

2020 ◽  
Vol 22 (4) ◽  
pp. 1105-1112 ◽  
Author(s):  
Xuan Xu ◽  
Saso Sturm ◽  
Zoran Samardzija ◽  
Janez Scancar ◽  
Katarina Markovic ◽  
...  

A closed loop of recovering rare-earth elements and transition metals from Nd–Fe–B magnets with the total re-use of the electrolyte using a facile electrolysis-selective precipitation procedure.


2015 ◽  
Vol 156 ◽  
pp. 239-258 ◽  
Author(s):  
Cristian Tunsu ◽  
Martina Petranikova ◽  
Marino Gergorić ◽  
Christian Ekberg ◽  
Teodora Retegan

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1049
Author(s):  
Khalid A. M. Salih ◽  
Mohammed F. Hamza ◽  
Hamed Mira ◽  
Yuezhou Wei ◽  
Feng Gao ◽  
...  

The strong demand for rare-earth elements (REEs) is driven by their wide use in high-tech devices. New processes have to be developed for valorizing low-grade ores or alternative metal sources (such as wastes and spent materials). The present work contributed to the development of new sorbents for the recovery of rare earth ions from aqueous solutions. Functionalized mesoporous silica composite was synthesized by grafting diethylenetriamine onto composite support. The physical and chemical properties of the new sorbent are characterized using BET, TGA, elemental analysis, titration, FTIR, and XPS spectroscopies to identify the reactive groups (amine groups: 3.25 mmol N g−1 and 3.41 by EA and titration, respectively) and their mode of interaction with Nd(III) and Gd(III). The sorption capacity at the optimum pH (i.e., 4) reaches 0.9 mmol Nd g−1 and 1 mmol Gd g−1. Uptake kinetics are modeled by the pseudo-first-order rate equation (equilibrium time: 30–40 min). At pH close to 4–5, the sorbent shows high selectivity for rare-earth elements against alkali-earth elements. This selectivity is confirmed by the efficient recovery of REEs from acidic leachates of gibbsite ore. After elution (using 0.5 M HCl solutions), selective precipitation (using oxalate solutions), and calcination, pure rare earth oxides were obtained. The sorbent shows promising perspective due to its high and fast sorption properties for REEs, good recycling, and high selectivity.


2022 ◽  
Vol 176 ◽  
pp. 107361
Author(s):  
Payam Rasoulnia ◽  
Robert Barthen ◽  
Aino-Maija Lakaniemi ◽  
Harri Ali-Löytty ◽  
Jaakko A. Puhakka

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 721 ◽  
Author(s):  
Marino Gergoric ◽  
Christophe Ravaux ◽  
Britt-Marie Steenari ◽  
Fredrik Espegren ◽  
Teodora Retegan

Over the last decade, rare-earth elements (REEs) have become critical in the European Union (EU) in terms of supply risk, and they remain critical to this day. End-of-life electronic scrap (e-scrap) recycling can provide a partial solution to the supply of REEs in the EU. One such product is end-of-life neodymium (NdFeB) magnets, which can be a feasible source of Nd, Dy, and Pr. REEs are normally leached out of NdFeB magnet waste using strong mineral acids, which can have an adverse impact on the environment in case of accidental release. Organic acids can be a solution to this problem due to easier handling, degradability, and less poisonous gas evolution during leaching. However, the literature on leaching NdFeB magnets waste with organic acids is very scarce and poorly investigated. This paper investigates the recovery of Nd, Pr, and Dy from NdFeB magnets waste powder using leaching and solvent extraction. The goal was to determine potential selectivity between the recovery of REEs and other impurities in the material. Citric acid and acetic acid were used as leaching agents, while di-(2-ethylhexyl) phosphoric acid (D2EHPA) was used for preliminary solvent extraction tests. The highest leaching efficiencies were achieved with 1 mol/L citric acid (where almost 100% of the REEs were leached after 24 h) and 1 mol/L acetic acid (where >95% of the REEs were leached). Fe and Co—two major impurities—were co-leached into the solution, and no leaching selectivity was achieved between the impurities and the REEs. The solvent extraction experiments with D2EHPA in Solvent 70 on 1 mol/L leachates of both acetic acid and citric acid showed much higher affinity for Nd than Fe, with better extraction properties observed in acetic acid leachate. The results showed that acetic acid and citric acid are feasible for the recovery of REEs out of NdFeB waste under certain conditions.


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