Effect of the Temperature Conditions of Sulfation Process on Extraction of Rare-Earth Metals from Refractory Ore

Bochevskaya, Yelena; Абишева, З. С.; Karshigina, Z. B.; Sargelova, Elmira Abdikhalikovna; Kvyatkovskaya, Marina N.; Akchulakova, S. T.

doi:10.1007/s11015-018-0695-x

Cited by 2 publications

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“…Cerianite is tetravalent cerium dioxide (CeO 2 ) and has the fluorite structure (space group (Fm3m)) [1]. In nature, cerianite exists in rare earth ores [2][3][4][5]. Cerianite has oxygen storage capacity due to a facile redox reaction from tetra-to trivalent cerium, as described in Equation (1) [6], and the ability to improve dispersion of noble metals [7] and provide thermal stabilization of alumina supports [8].…”

Section: Introductionmentioning

confidence: 99%

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Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-Ray Absorption Fine Structure

et al. 2019

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Prolonged high-intensity grinding can modify the crystal structure of solid substances and/or induce chemical reaction, which is referred to as mechanochemical reaction. Such reactions can exert positive influences on hydrometallurgical processes, therefore, many researchers have applied mechanochemical reactions for metals dissolution from minerals. The mechanism of mechanochemical reaction has been investigated using solid analyses and simulations. Structural changes caused by mechanochemical reactions are not yet sufficiently clarified because the ground samples are amorphous. The objective of this study was to analyze structural changes of cerianite in weathered residual rare earth ore by mechanochemical reduction. The ore was ground by planetary ball milling for 10, 60 and 720 min. Structural change was analyzed by the X-ray absorption near-edge structure and extended x-ray absorption fine structure analysis at the cerium LIII- and K-edges. These analyses revealed that the structural change of cerianite in this ore induced by mechanochemical reduction involved oxygen vacancy production. The process of the oxygen vacancy formation was closely coupled with the quantum effect of localization–delocalization of the 4f electron of cerium.

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Section: Introductionmentioning

confidence: 99%

“…k3 -weighted cerium K-edge extended X-ray absorption fine structure spectra of tetravalent cerium oxide for samples with and without grinding.…”

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confidence: 99%

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-Ray Absorption Fine Structure

et al. 2019

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“…Cerianite is tetravalent cerium dioxide (CeO2) and has the fluorite structure (space group ( 3 )) [1]. In nature, cerianite exists in rare earth ores [2][3][4][5]. Cerianite has oxygen storage capacity due to a facile redox reaction from tetra-to trivalent cerium, as described in equation (1) [6], and the ability to improve dispersion of noble metals [7] and provide thermal stabilization of alumina supports [8].…”

Section: Introductionmentioning

confidence: 99%

“…Cerium phosphate (CePO4) and CeO2 were used as reference materials.The EXAFS functions were derived from the raw XAFS spectra by pre-and post-edge linear background subtraction and then normalized with respect to the edge jump. After being k 3weighted, where k is the photoelectron wave number, the EXAFS function was Fourier transformed from the k3 -weighted EXAFS function to a radial distribution function (RDF) using a Hanning window function within 1-12 × 10 10 m −1 . Structural parameters for different coordination shells surrounding both the central tri-and tetravalent cerium atoms, i.e., coordination number, atomic distance, and Debye-Waller factor, were obtained by curve fitting using both the k 3weighted EXAFS function and RDF.…”

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Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-ray Absorption Fine Structure

Kato¹,

Tsunazawa

Liu

et al. 2019

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Prolonged high-intensity grinding can modify the crystal structure of solid substances and/or induce chemical reaction, which is referred to as mechanochemical reaction. Such reactions can exert positive influences on hydrometallurgical processes, therefore, many researchers have applied mechanochemical reactions for metals dissolution from minerals. The mechanism of mechanochemical reaction has been investigated using solid analyses and simulations. Structural changes caused by mechanochemical reaction are not yet sufficiently clarified because the ground samples are amorphous. The objective of this study was to analyze structural changes of cerianite in weathered residual rare earth ore by mechanochemical reduction. Structural change was analyzed by x-ray absorption near-edge structure and extended x-ray absorption fine structure analysis at the cerium LIII- and K-edges. These analyses revealed that the structural change of cerianite in this ore induced by mechanochemical reduction involved oxygen vacancy production. The process of the oxygen vacancy formation was closely coupled with the quantum effect of localization–delocalization of the 4f electron of cerium.

show abstract

Effect of the Temperature Conditions of Sulfation Process on Extraction of Rare-Earth Metals from Refractory Ore

Cited by 2 publications

References 7 publications

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-Ray Absorption Fine Structure

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-Ray Absorption Fine Structure

Structural Change Analysis of Cerianite in Weathered Residual Rare Earth Ore by Mechanochemical Reduction Using X-ray Absorption Fine Structure

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