Recovery of Rare Earth Elements from Waste Permanent Magnets Leach Liquors

2020 ◽  
pp. 335-345 ◽  
Author(s):  
Rajesh Kumar Jyothi ◽  
Kyeong Woo Chung ◽  
Chul-Joo Kim ◽  
Ho-Sung Yoon
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Permanent Magnets

A DETERMINATION OF THE SHEAR FORCE OF THIN HIGH-COERCIVITY PERMANENT MAGNETS MADE FROM THE ALLOY WITH RARE-EARTH ELEMENTS

2021 ◽  
pp. 24-30
Author(s):  
A. Ya. Krasilʼnikov ◽  
A. A. Krasilʼnikov
Keyword(s):  
Rare Earth ◽  
Magnetic Flux ◽  
Rare Earth Elements ◽  
Standard Method ◽  
Shear Force ◽  
Permanent Magnets ◽  
High Coercivity ◽  
Research Results ◽  
Magnetic Couplings

The article considers the possibility of using a standard method for calculating the shear force of thin, high-coercivity neodymium–iron–boron type permanent magnets in magnetic clutches (couplings). The research results allowed to introduce a correction coefficients in the method of calculating the transmitting torque in magnetic clutches (couplings) with thin magnets. The possibility of 08H22N6T brand steel using for magnetic flux conductors manufacturing in a magnetic couplings.

Rare earth elements and permanent magnets (invited)

2012 ◽  
Vol 111 (7) ◽  
pp. 07A721 ◽  
Author(s):  
Peter C. Dent
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Permanent Magnets

scholarly journals Selective Roasting of Nd–Fe‒B Permanent Magnets as a Pretreatment Step for Intensified Leaching with an Ionic Liquid

2019 ◽  
Vol 6 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Martina Orefice ◽  
Amy Van den Bulck ◽  
Bart Blanpain ◽  
Koen Binnemans
Keyword(s):  
Ionic Liquid ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Permanent Magnets ◽  
Metallic Phase ◽  
Process Step ◽  
Mechanical Removal ◽  
Oxidative Roasting ◽  
Roasting Temperature ◽  
The Rare Earth

AbstractOxidative roasting of Nd–Fe‒B permanent magnets prior to leaching improves the selectivity in the recovery of rare-earth elements over iron. However, the dissolution rate of oxidatively roasted Nd–Fe‒B permanent magnets in acidic solutions is very slow, often longer than 24 h. Upon roasting in air at temperatures above 500 °C, the neodymium metal is not converted to Nd2O3, but rather to the ternary NdFeO3 phase. NdFeO3 is much more difficult to dissolve than Nd2O3. In this work, the formation of NdFeO3 was avoided by roasting Nd–Fe‒B permanent magnet production scrap in argon atmosphere, having an oxygen content of $$ p_{{{\text{O}}_{2} }} \, \le \,10^{ - 20} \;{\text{atm}}, $$pO2≤10-20atm, with the addition of 5 wt% of carbon as an iron reducing agent. For all the non-oxidizing iron roasting conditions investigated, the iron in the Nd–Fe‒B scrap formed a cobalt-containing metallic phase, clearly distinct from the rare-earth phase at microscopic level. The thermal treatment was optimized to obtain a clear phase separation of metallic iron and rare-earth phase also at the macroscopic level, to enable easy mechanical removal of iron prior to the leaching step. The sample roasted at the optimum conditions (i.e., 5 wt% carbon, no flux, no quenching step, roasting temperature of 1400 °C and roasting time of 2 h) was leached in the water-containing ionic liquid betainium bis(trifluoromethylsulfonyl)imide, [Hbet][Tf2N]. A leaching time of only 20 min was sufficient to completely dissolve the rare-earth elements. The rare-earth elements/iron ratio in the leachate was about 50 times higher than the initial rare-earth elements/iron ratio in the Nd–Fe‒B scrap. Therefore, roasting in argon with addition of a small amount of carbon is an efficient process step to avoid the formation of NdFeO3 and to separate the rare-earth elements from the iron, resulting in selective leaching for the recovery of rare-earth elements from Nd–Fe‒B permanent magnets.

Determination of the Shear Force of High-Coercivity Permanent Magnets Produced from A 5-MM Thick Alloy of Rare-Earth Elements

2020 ◽  
Vol 55 (11-12) ◽  
pp. 1007-1015
Author(s):  
A. Ya. Krasil’nikov ◽  
A. A. Krasil’nikov ◽  
D. V. Taranov
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Shear Force ◽  
Permanent Magnets ◽  
High Coercivity

ChemInform Abstract: Rare Earth Elements and Permanent Magnets (Invited)

ChemInform ◽  
2012 ◽  
Vol 43 (25) ◽  
pp. no-no
Author(s):  
Peter C. Dent
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Permanent Magnets

scholarly journals Optimisation of Permanent Magnets of Bioreactor Magnetic Coupling while Preserving their Efficiency

2019 ◽  
Vol 56 (4) ◽  
pp. 38-48
Author(s):  
M. Konuhova ◽  
E. Kamolins ◽  
S. Orlova ◽  
A. Suleiko ◽  
R. Otankis
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Permanent Magnets ◽  
Magnetic Coupling ◽  
Economic Aspect ◽  
Maximum Torque ◽  
Factors Affecting ◽  
Magnetic Couplings ◽  
Breakaway Torque

Abstract The paper discusses issues related to the optimisation of magnetic couplings used in bioreactors (manufactured by JSC “Biotehniskais Centrs”). The purpose of optimisation was to preserve the maximum breakaway torque of the magnetic coupling while reducing the mass of rare earth elements used in its structure. The paper presents the rationale for the selected optimisation option taking into account the economic aspect. To solve the optimisation problem, the factors affecting the maximum torque of the magnetic coupling, such as the shape and height of the internal and external magnets, the angle of the external and internal magnets, as well as the height of the internal and external yoke, were determined. The design of the existing magnetic coupling was optimised and its prototype was made based on the results of optimisation. The results obtained by means of optimisation were compared with the results obtained experimentally by testing the manufactured prototype.

scholarly journals Recent advances in acid-free dissolution and separation of rare earth elements from the magnet waste

2021 ◽  
Vol 1 (2) ◽  
pp. 112-123
Author(s):  
Grace Inman ◽  
◽  
Denis Prodius ◽  
Ikenna C. Nlebedim
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Energy Efficient ◽  
Permanent Magnets ◽  
Environmentally Friendly ◽  
Key Factors ◽  
Recent Advances ◽  
The U.S

<abstract> <p>The availability of REEs is limiting the successful deployment of some environmentally friendly and energy-efficient technologies. In 2019, the U.S. generated more than 15.25 billion pounds of e-waste. Only ~15% of it was handled, leaving ~13 billion pounds of e-waste as potential pollutants. Of the 15% collected, the lack of robust technology limited REE recovery for re-use. Key factors that drive the recycling of permanent magnets based on rare earth elements (REEs) and the results of our research on magnet recycling will be discussed, with emphasis on neodymium and samarium-based rare earth permanent magnets.</p> </abstract>

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