Hydrogen in-situ refining method for preparing high purity gadolinium

Li, Guoling; Li, Li; Fu, Kai; Wang, Chongyun; Zheng, Jie; Xu, Li; Tian, Wenjie; Li, Xingguo

doi:10.1016/j.jallcom.2015.06.222

Cited by 10 publications

(8 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When used as a magnetocaloric material, high purity Gd is desired [ 18 , 19 ]. Commonly, gadolinium is prepared from gadolinium oxide (99%), and the final metal is obtained using fluorination, reduction, and distillation processes, as well as ultra-purification procedures such as zone refining and solid-state electro transport [ 18 , 31 ].…”

Section: Discussionmentioning

confidence: 99%

“…However, one of the most important factors when choosing Gd as a magnetocaloric material is its purity [ 18 , 19 ]. There have been few detailed studies highlighting the metallic impurities in Gd.…”

Section: Introductionmentioning

confidence: 99%

“…These studies have predominantly focused on the interstitial impurities, such as O, N, and C. The various impurities present in Gd metal can be classified as follows: (i) rare-earth metallic impurities; (ii) alkali and alkali-earth metallic impurities; and (iii) others, e.g., Ti impurities [ 18 ]. Recently, an effective approach to prepare high purity Gd via hydrogen in-situ refining method for removing O and N was proposed in detail by Li et al [ 19 ].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Microstructural Anisotropy of Magnetocaloric Gadolinium Cylinders: Effect on the Mechanical Properties of the Material

et al. 2016

View full text Add to dashboard Cite

The development of advanced materials and technologies based on magnetocaloric Gd and its compounds requires an understanding of the dependency of mechanical properties on their underlying microstructure. Therefore, the aim of the study was to characterize microstructural inhomogeneities in the gadolinium that can be used in magnetocaloric refrigeration systems. Microstructures of magnetocaloric gadolinium cylinders were investigated by light microscopy and FE-SEM (Field Emission Scanning Electron Microscopy), EDS (Energy-dispersive X-ray Spectroscopy), and BSE (Back-scattered Electrons) in both the extrusion and the extrusion-transversal directions. XRD (X-ray Diffraction) analyses were performed to reveal the presence of calcium- and fluorine-based compounds. Metallographic characterization showed an oxidized and inhomogeneous microstructure of the cross-sections. The edges and the outer parts of the cylinders were oxidized more intensively on the surfaces directly exposed to the processing tools. Moreover, a significant morphological anisotropy of the non-metallic inclusions was observed. CaF inclusions act as active nucleation sites for internal oxidation. The non-metallic, Ca- and F-containing inclusions can be classified as complex calciumoxyfluorides. The solubility of Er and Yb in the CaF was negligible compared to the Gd matrix and/or the oxide phase. Lower mechanical properties of the material are a consequence of the lower structural integrity due to selective oxidation of surfaces and interfaces.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Microstructural Anisotropy of Magnetocaloric Gadolinium Cylinders: Effect on the Mechanical Properties of the Material

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Consequently, also, the PMI (E-factor + 1) resulted sensibly lower for mechanochemistry (1.29 and 1.30 for 35a and 35b respectively) compared to solution-based reactions (17 and 240 35a and 35b respectively). [90][91][92] Moreover, the mechanochemical strategy avoids using toxic solvents (DMF, ACN), excess reagents, corrosive highly concentrated solutions of strong acids, and bases for synthesis and workup. Also, there is no need for pH adjustments or heating-cooling thermal cycles -which strongly reduces the environmental impact and production cost and improves the process's safety.…”

Section: Green Metrics Used In Mechanochemical Reactionsmentioning

confidence: 99%

Green metrics in mechanochemistry

Fantozzi,

Volle,

Porcheddu

et al. 2023

Chem. Soc. Rev.

View full text Add to dashboard Cite

show abstract

“…However, its significant weight loss and high cost have hindered the wide use of EBM. Recently, hydrogen plasma arc melting (HPAM) was developed for refining active metals such as Hf, Cr, Zr, Nb, Ti, Tb, and Gd [14,15,16,17,18,19,20,21,22]. It was found that hydrogen in the plasma could increase the efficiency of metallic impurity removal.…”

Section: Introductionmentioning

confidence: 99%

Manganese Removal from Liquid Nickel by Hydrogen Plasma Arc Melting

Guo

Hou

et al. 2018

Materials

View full text Add to dashboard Cite

In this work, the removal of manganese from nickel melts by Ar and (10%, 20% and 40%) H2 plasma arc melting under various pressures (0.01–0.02, 0.04–0.05 and 0.09–0.1 MPa) was investigated experimentally. The results show that only a slight reduction in the manganese content is obtained by Ar plasma arc melting (PAM). By contrast, the manganese content of liquid nickel decreases noticeably upon the addition of hydrogen to plasma gas, and the rate of manganese removal increases with increasing hydrogen volume fraction. In addition, the reduction in the pressure enhances the efficiency of manganese removal from liquid nickel by hydrogen plasma arc melting (HPAM). The process of manganese removal by HPAM was found to obey a first-order rate law. From kinetic analysis, the rate of reduction in the manganese content increases proportionally to the 0.73–0.75th power of the hydrogen volume fraction in the plasma gas. However, the rate of the manganese content reduction increases proportionally to approximately 0.88th power of %H2 in the plasma gas for the initial manganese content of 0.89 mass%, which is slightly higher than that for the initial manganese concentration of 0.45 mass%. Thermodynamic analysis indicates that the volatilization of manganese benefits from negative pressure and the presence of active hydrogen atoms that act as the transfer media of the metal vapor in the gas boundary layer.

show abstract

Hydrogen in-situ refining method for preparing high purity gadolinium

Cited by 10 publications

References 20 publications

Microstructural Anisotropy of Magnetocaloric Gadolinium Cylinders: Effect on the Mechanical Properties of the Material

Microstructural Anisotropy of Magnetocaloric Gadolinium Cylinders: Effect on the Mechanical Properties of the Material

Green metrics in mechanochemistry

Manganese Removal from Liquid Nickel by Hydrogen Plasma Arc Melting

Contact Info

Product

Resources

About