Thermodynamic optimization of the Dy–Nd–Fe–B system and application in the recovery and recycling of rare earth metals from NdFeB magnet

2015 ◽  
Vol 17 (4) ◽  
pp. 2246-2262 ◽  
Author(s):  
Marie-Aline Van Ende ◽  
In-Ho Jung ◽  
Yong-Hwan Kim ◽  
Taek-Soo Kim
Keyword(s):  
Rare Earth ◽  
Liquid Metal ◽  
Phase Diagrams ◽  
Rare Earth Metals ◽  
Extraction Process ◽  
Metal Extraction ◽  
Thermodynamic Optimization ◽  
Ndfeb Magnet ◽  
Complex Phase ◽  
Selective Recovery

The developed thermodynamic database for the Dy–Nd–Fe–B–Mg system enables the calculation of complex phase diagrams for the selective recovery of Nd and Dy from NdFeB magnet scrap using the liquid metal extraction process.

Phase Equilibria in a Liquid Metal of Fe-La-Ce-O System at 1600 °С

2020 ◽  
Vol 299 ◽  
pp. 468-474 ◽  
Author(s):  
Gennady G. Mikhailov ◽  
L.A. Makrovets ◽  
O.V. Samoilova
Keyword(s):  
Rare Earth ◽  
Liquid Metal ◽  
Phase Equilibria ◽  
Phase Diagrams ◽  
Liquid Iron ◽  
Rare Earth Metals ◽  
Liquid Oxygen ◽  
Oxide Systems ◽  
Calculation Technique ◽  
Steelmaking Technology

Thermodynamic modeling of phase equilibria in a liquid metal of Fe–La–Ce–O system at 1600 °С, using the technique of constructing the solubility surfaces for the components of a metal, was carried out. The calculation technique allowed assessing the depth of liquid iron de-oxidation at a complex use of lanthanum and cerium as deoxidizing agents. Also, diagrams of de-oxidants’ consumption for one ton of liquid oxygen-containing iron were calculated in the course of the work. Carrying out a calculation of the solubility surfaces for the components of a metal required simulation of phase diagrams of the following oxide systems: FeO–La2O3–Ce2O3, FeO–CeO2–La2O3, CeO2–La2O3–Ce2O3. The obtained results might be of interest for optimization of the use of rare-earth metals in steelmaking technology.

THERMODYNAMICS OF THE PROCESSES OF INTERACTION OF LIQUID METAL COMPONENTS IN Fe – Mg – Al – La – O SYSTEM

2018 ◽  
Vol 61 (6) ◽  
pp. 460-465
Author(s):  
G. G. Mikhailov ◽  
L. A. Makrovets ◽  
L. A. Smirnov
Keyword(s):  
Rare Earth ◽  
Liquid Metal ◽  
Rare Earth Elements ◽  
Phase Equilibria ◽  
Thermodynamic Modeling ◽  
Equilibrium Constants ◽  
Rare Earth Metals ◽  
Oxide Systems ◽  
Metal Melts ◽  
Steel Deoxidation

At the present time, rare-earth elements in metallurgy are used in  the form of mischmetal – a rare-earth elements natural mixture (with  atomic numbers from 57 to 71). It contains about 50  wt.  % of cerium.  The remaining elements are mainly lanthanum and niobium. The specific composition is determined by the ore deposit. Inconstant composition of the modifier containing rare-earth metals (REM) can significantly reduce its efficiency. Experimentally, for every branded steels  composition the ratio of various REMs can’t be selected because of the  high costs of obtaining technically pure rare-earth metals. The task of  determining the each rare earth element optimum concentrations and  complex ligature composition can be solved by thermodynamic modeling. In the framework of thermodynamic modeling, the interaction  between magnesium, aluminum and lanthanum with oxygen in liquid  iron is presented. And the thermodynamic model of steel deoxidation  by these active metals composition is considered. On the basis of available literature data on the phase diagrams of the systems MgO – Al2O3 ,  MgO – La2O3 and La2O3 – Al2O3 , the coordinates of the invariant equilibria points in the system MgO – La2O3 – Al2O3 were determined. The  phase diagram of the system MgO – La2O3 – Al2O3 was constructed. It  made possible to establish all phase equilibria realized in the process  of deoxidation of steel with magnesium, lanthanum and aluminum and  to describe these phase equilibria by chemical reactions equations. The  activity of the components in liquid oxide melts was determined using  the theory of subregular ionic solutions, which takes into account the  dependence of the coordination number of cations on the composition  of the oxide melt. The activity of components in metal melts conjugated with oxide systems were determined by Wagner’s theory using the  parameters of the first order interaction. Equilibrium constants values  for the steel deoxidation reactions are installed indirectly by thermodynamic calculations. On the basis of the obtained data the components  solubility surface in the metal melts of Fe – Mg – Al – La – O system  was constructed, which allowed to determine the liquid metal composition regions associated with the corresponding oxide phase.

Selective Extraction and Recovery of Rare Earth Metals (REMs) from NdFeB Magnet Grinding Sludge

2018 ◽  
pp. 2399-2407 ◽  
Author(s):  
Waraporn Piyawit ◽  
Pisit Sawananusorn ◽  
Loeslakkhana Srikhang ◽  
Panya Buahombura ◽  
Narong Akkarapattanagoon ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Metals ◽  
Selective Extraction ◽  
Ndfeb Magnet

Binary phase diagrams of the rare earth metals with zinc: the Tb–Zn, Ho–Zn and Er–Zn systems

2005 ◽  
Vol 96 (12) ◽  
pp. 1369-1379 ◽  
Author(s):  
Adriana Saccone ◽  
Anna Maria Cardinale ◽  
Stefano Delfino ◽  
Riccardo Ferro
Keyword(s):  
Rare Earth ◽  
Phase Diagrams ◽  
Rare Earth Metals ◽  
Binary Phase ◽  
Binary Phase Diagrams ◽  
The Rare Earth

scholarly journals Influence of Rare Earth Metals on Microstructure and Inclusions Morphology G17CrMo5-5 Cast Steel

2014 ◽  
Vol 59 (3) ◽  
pp. 993-996 ◽  
Author(s):  
J. Kasińska
Keyword(s):  
Rare Earth ◽  
Carbon Steel ◽  
Liquid Metal ◽  
Cast Steel ◽  
Rare Earth Metals ◽  
Metallic Inclusions

Abstract This paper presents influence of rare earth metals (REM) on the microstructure and morphology of non-metallic inclusions of G17CrMo5-5 cast carbon steel The research has been performed on successive industrial melts. Each time about 2000 kg of liquid metal was modified. The REM was in the form of mishmetal of the composition 49, 8% Ce, 21, 8% La, 17, 1% Nd, 5, 5% Pr and 5, 35% the rest of REM. Therareearth metals were put into the ladle during tapping of heat melt from the furnace.

Hydrometallurgical Process for Selective Extraction of Nd and Rare-Earth Metals from End-of-Life Hard Disk Drives NdFeB Magnet Scrap

2020 ◽  
Vol 845 ◽  
pp. 81-86
Author(s):  
Panya Buahombura ◽  
Anuthai Kareram ◽  
Waraporn Piyawit ◽  
Sarum Boonmee
Keyword(s):  
Rare Earth ◽  
Acid Solution ◽  
End Of Life ◽  
Rare Earth Metals ◽  
Hard Disk Drives ◽  
Hard Disk ◽  
Hydrometallurgical Process ◽  
Disk Drives ◽  
Ndfeb Magnet ◽  
Xrd Pattern

This paper proposed a recycling process for neodymium-iron-boron (NdFeB) magnet scrap from the end-of-life (EOL) of hard disk drives by using hydrometallurgical process. Initial chemical composition of NdFeB magnet scrap was consisted of 25.37%Nd, 6.53%Pr, 0.90%Co, 3.63%B and 63.57%Fe. After de-magnetization and crushing into proper size, magnet scraps were directly leached by H2SO4 solution. More than 90% dissolved into acid solution with remaining small amount of residuals and Ni-coated metal. Neodymium precipitated from leached solution by pH-control to the optimum condition at pH 0.6 using NaOH solution. Solid Nd-precipitates XRD pattern was observed in form of NaNd (SO4)2.(H2O) and FeSO4.(H2O). Elemental analysis of Nd-precipitates by WD-XRF. The precipitates contained 26.50%Nd, 8.46%Pr and 1.19%Fe. In order to elimination of Fe, Nd-precipitates was leached by using H2SO4 solution to dissolve FeSO4.(H2O) into acid solution to obtain high concentration of Nd and rare-earth metals (REMs) compound. As a result, XRD pattern of Nd-compound after Fe-removal confirmed that the high purity NaNd (SO4)2.(H2O) compound was obtained. The final composition of precipitates analyzed by WD-XRF was 26.36%Nd, 8.13%Pr with Fe as low as 0.14%Fe.

Review of the Liquid Metal Extraction Process for the Recovery of Nd and Dy from Permanent Magnets

2021 ◽  
Author(s):  
Mohammad Zarar Rasheed ◽  
Sun-Woo Nam ◽  
Ju-Young Cho ◽  
Kyoung-Tae Park ◽  
Bum-Sung Kim ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Permanent Magnets ◽  
Extraction Process ◽  
Metal Extraction

ChemInform Abstract: PHASE DIAGRAMS OF RARE EARTH METALS WITH GALLIUM

1979 ◽  
Vol 10 (44) ◽  
Author(s):  
S. P. YATSENKO ◽  
A. A. SEMYANNIKOV ◽  
B. G. SEMENOV ◽  
K. A. CHUNTONOV
Keyword(s):  
Rare Earth ◽  
Phase Diagrams ◽  
Rare Earth Metals
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