Molar Volume and Electrical Conductivity Measurements in the Ternary Molten Salt System NaCl ‐ CsCl ‐ MnCl2 : II . Electrical Conductivities

Abstract Starting with the same sample, the electrical conductivities of quartz and coesite have been measured at pressures of 1, 6, and 8.7 GPa, respectively, over a temperature range of 373–1273 K in a multi-anvil high-pressure system. Results indicate that the electrical conductivity in quartz increases with pressure as well as when the phase change from quartz to coesite occurs, while the activation enthalpy decreases with increasing pressure. Activation enthalpies of 0.89, 0.56, and 0.46 eV, were determined at 1, 6, and 8.7 GPa, respectively, giving an activation volume of –0.052 ± 0.006 cm3/mol. FTIR and composition analysis indicate that the electrical conductivities in silica polymorphs is controlled by substitution of silicon by aluminum with hydrogen charge compensation. Comparing with electrical conductivity measurements in stishovite, reported by Yoshino et al. (2014), our results fall within the aluminum and water content extremes measured in stishovite at 12 GPa. The resulting electrical conductivity model is mapped over the magnetotelluric profile obtained through the tectonically stable Northern Australian Craton. Given their relative abundances, these results imply potentially high electrical conductivities in the crust and mantle from contributions of silica polymorphs. The main results of this paper are as follows:The electrical conductivity of silica polymorphs is determined by impedance spectroscopy up to 8.7 GPa.The activation enthalpy decreases with increasing pressure indicating a negative activation volume across the silica polymorphs.The electrical conductivity results are consistent with measurements observed in stishovite at 12 GPa.

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Molecular Dynamics Simulation Study of the Effect of Ni, Fe, Cu on Cryolite Molten Salt System 78% Na3AlF6-9.5%AlF3-5.0%CaF2-7.5%-Al2O3

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1026.39 ◽

2021 ◽

Vol 1026 ◽

pp. 39-48

Author(s):

Han Bing He ◽

Yu Si Wang ◽

Ze Xiang Luo ◽

Jing Zeng

Keyword(s):

Molecular Dynamics ◽

Diffusion Coefficient ◽

Molten Salt ◽

Diffusion Mechanism ◽

Research Work ◽

Dynamics Simulation ◽

Salt System ◽

Electrolyte System ◽

Aluminum Composite ◽

Molten Salt System

The effect of different additives Ni, Fe, Cu on the structure and properties of electrolyte system 78% Na3AlF6- -9.5%AlF3-5.0%CaF2-7.5%Al2O3 at 1200K and 1.01Mpa was studied by molecular dynamics method. The radial distribution function, coordination number, diffusion coefficient, conductivity, and viscosity of the system were discussed in detail. The results demonstrated that the order of the self-diffusion coefficient of ions in the electrolyte system is: Na+ > F- > O2- > Ca2+ >Al3+. The addition of Ni and Fe connected the free aluminum composite ion groups in the system through fluorine bridges, which enhanced the interaction between Al3+ and Al3+. The addition of Cu weakened the interaction between Al3 + and Al3+ and the F-. The interaction between Al3+ and Na+, [AlF7]4- ionic groups might appeared in the melt system. After adding NiO, Fe2O3, and Cu, the electrical conductivity of the system increased, and the viscosity decreased. The research work revealed the influence of Ni, Fe, Cu on the ion existence form, mobility, inter-ion interaction and diffusion mechanism of cryolite molten salt system, which has important guiding significance for aluminum electrolysis production.

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First-principles molecular dynamics investigation on KF-NaF-AlF3 molten salt system

Chemical Physics Letters ◽

10.1016/j.cplett.2019.06.060 ◽

2019 ◽

Vol 730 ◽

pp. 587-593 ◽

Cited By ~ 1

Author(s):

Hui Guo ◽

Jie Li ◽

Hongliang Zhang ◽

Tianshuang Li ◽

Jiawei Luo ◽

...

Keyword(s):

Molecular Dynamics ◽

Molten Salt ◽

First Principles ◽

Salt System ◽

Molten Salt System ◽

First Principles Molecular Dynamics

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ChemInform Abstract: Experimental Observations of a Thoria Oxide-Ion Sensor in a Molten Salt System.

ChemInform ◽

10.1002/chin.200220015 ◽

2010 ◽

Vol 33 (20) ◽

pp. no-no

Author(s):

S. X. Li ◽

S. D. Herrmann

Keyword(s):

Molten Salt ◽

Salt System ◽

Ion Sensor ◽

Molten Salt System ◽

Oxide Ion

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Effect of Na3WO3F3 Content on the Liquidus Temperature of NaCl-KCl-Na3WO3F3 Molten Salt System

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.908.159 ◽

2014 ◽

Vol 908 ◽

pp. 159-162

Author(s):

Jie Li ◽

Yang Pei ◽

Ya Bin Liu ◽

Yun Gang Li

Keyword(s):

Thermal Analysis ◽

Differential Thermal Analysis ◽

Molten Salt ◽

Liquidus Temperature ◽

Eutectic Composition ◽

Eutectic Temperature ◽

Salt System ◽

Molten Salt System

The liquidus temperature of molten salt NaCl-KCl-Na3WO3F3 system was measured by differential thermal analysis. The results show that in the molten salt system when XNaCl:XKCl=1:1, XNa3WO3F3<0.6 the liquidus temperature decreased with increase of Na3WO3F3 content; when XNaCl:XKCl=1:1, XNa3WO3F3> 0.6 the liquidus temperature increased with the increase of Na3WO3F3 content; the eutectic temperature is 612.9 °C, the eutectic composition is XNaCl=0.2, XKCl=0.2, XNa3WO3F3=0.6.

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