Immiscibility of Fluoride–Calcium and Silicate Melts in Trachyrhyolitic Magma: Data on Acidic Volcanic Rocks from the Nyalga Basin, Central Mongolia

Peretyazhko, I. S.; Savina, Elena; Карманов, Н. С.; Dmitrieva, A. S.

doi:10.1134/s0869591118040069

Cited by 9 publications

(3 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…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%

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

et al. 2019

View full text Add to dashboard Cite

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.

show abstract

Section: Introductionmentioning

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

View full text Add to dashboard Cite

show abstract

“…Silicate melts are produced from silica (SiO 2 ) and compounds based on it -silicates [3,4]. Common rocks (sand, basalt, diabase, and marl) [5], industrial by-products (metallurgical slags and ashes) [6], and secondary raw materials (cullet) [7] are used as raw materials to produce silicate melts. Materials and products with different structures and properties, including glass, glass products, and glass-crystalline and partially crystallized materials can be produced from silicate melts depending on the initial feedstock that determines the chemical melt composition and the cooling mode.…”

Section: Introductionmentioning

confidence: 99%

Mathematical Modeling of the Melting Process of Silicate Materials in a Plasma Reactor

2021

View full text Add to dashboard Cite

Results of mathematical modeling of the melting process of silicate materials in a plasma reactor are presented. Quartz sand containing up to ~98 wt% SiO 2 was used as a model material. It has been found that in the initial period of time at the temperature T f = 2500 K of the air-plasma medium, the gas temperature near the phase interface is below the melting temperature. As a result of heat exchange in the gas phase, the thermal energy is transferred first from the central and then from the upper layers of the material to the phase interface. If the thermal energy in the gas phase turns out to be sufficient for the phase transition, then melting begins after some time. When the initial temperature increased to T f = 3000 K, melting begins almost instantly (t m = 0.2 s). In this case, the constant temperature slightly exceeding the melting temperature is established at the phase interface. It has been showed that the velocity of the melting front propagation is determined by the initial gas phase temperature and the thermal and physical characteristics of the material, but weakly depends on the thickness of the filling material layer.

show abstract

“…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%

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

Preprint

View full text Add to dashboard Cite

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

Immiscibility of Fluoride–Calcium and Silicate Melts in Trachyrhyolitic Magma: Data on Acidic Volcanic Rocks from the Nyalga Basin, Central Mongolia

Cited by 9 publications

References 29 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

Mathematical Modeling of the Melting Process of Silicate Materials in a Plasma Reactor

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

Contact Info

Product

Resources

About