Thermodynamic rationalization of molten-salt clectrodeposition in oxide-based systems

1989 ◽  
Vol 4 (6) ◽  
pp. 1495-1504 ◽  
Author(s):  
S. Crouch-Baker ◽  
R. A. Huggins
Keyword(s):  
Phase Diagram ◽  
Thermodynamic Properties ◽  
Molten Salt ◽  
Salt System ◽  
Single Crystalline ◽  
Crystalline Materials ◽  
Electrodeposition Process ◽  
Isothermal Phase Diagram ◽  
Molten Salt System ◽  
Salt Systems

Electrodeposition from molten-salt systems has been studied extensively as a method of producing both polycrystalline and single-crystalline materials. In this work, the thermodynamic aspects of the electrodeposition process are examined in a number of cases in which the molten-salt system behaves effectively as an oxygen-transporting medium, with particular reference to the thermodynamic properties of the melt. It is demonstrated how information gained from the construction of the appropriate isothermal phase diagram may be used to control and/or rationalize the behavior found in a given melt system on electrolysis.

Calculation of phase diagrams and thermodynamic properties of 14 additive and reciprocal ternary systems containing Li2CO3, Na2CO3, K2CO3, Li2SO4, Na2SO4, K2SO4, LiOH, NaOH, and KOH

1984 ◽  
Vol 62 (3) ◽  
pp. 457-474 ◽  
Author(s):  
A. D. Pelton ◽  
C. W. Bale ◽  
P. L. Lin
Keyword(s):  
Phase Diagram ◽  
Thermodynamic Properties ◽  
Molten Salt ◽  
Phase Diagrams ◽  
Binary Systems ◽  
Ternary Phase ◽  
Ternary Phase Diagram ◽  
Ternary Systems ◽  
Maximum Error ◽  
Critical Assessment

Phase diagrams and thermodynamic properties of five additive molten salt ternary systems and nine reciprocal molten salt ternary systems containing the ions Li+, Na+, [Formula: see text], OH− are calculated from the thermodynamic properties of their binary subsystems which were obtained previously by a critical assessment of the thermodynamic data and the phase diagrams in these binary systems. Thermodynamic properties of ternary liquid phases are estimated from the binary properties by means of the Conformal Ionic Solution Theory. The ternary phase diagrams are then calculated from these thermodynamic properties by means of computer programs designed for the purpose. It is found that a ternary phase diagram can generally be calculated in this way with a maximum error about twice that of the maximum error in the binary phase diagrams upon which the calculations are based. If, in addition, some reliable ternary phase diagram measurements are available, these can be used to obtain small ternary correction terms. In this way, ternary phase diagram measurements can be smoothed and the isotherms drawn in a thermodynamically correct way. The thermodynamic approach permits experimental data to be critically assessed in the light of thermodynamic principles and accepted solution models. A critical assessment of error limits on all the calculated ternary diagrams is made, and suggestions as to which composition regions merit further experimental study are given.

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

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.

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

2019 ◽  
Vol 730 ◽  
pp. 587-593 ◽  
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

Thermodynamic properties of the binary molten salt systems, PbBr2-KBr, PbBr2-RbBr and PbBr2-CsBr, by measurement of the electromotive forces of galvanic cells

1981 ◽  
Vol 34 (3) ◽  
pp. 479 ◽  
Author(s):  
H Bloom ◽  
MS White
Keyword(s):  
Thermodynamic Properties ◽  
Molten Salt ◽  
Activity Coefficients ◽  
Molten Salts ◽  
Free Energies ◽  
Complex Ions ◽  
Galvanic Cells ◽  
Salt Systems

The electromotive forces of galvanic cells for the formation of PbBr2 in the molten binary salt systems, PbBr2-KBr, PbBr2,-RbBr and PbBr2-CsBr, have been measured. Activities, activity coefficients and partial molar free energies have been calculated for each component of the three systems. Integral free energies of mixing have also been calculated. Various models of mixing of molten salts have been applied to the results. The systems contain complex ions, probably mixtures of PbBr42-, PbBr64- with some PbBr3-.

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

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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