Calculation of the Liquidus in Eutectic Salt Mixtures LiF–NaF, LiF–KF, NaF–KF, NaF–CsF, and KF–CsF Using a Thermodynamic Perturbation Theory

Autor: A. G. Davydov, N. K. Tkachev
Rok vydání: 2021
Předmět:
Zdroj: Russian Metallurgy (Metally). 2021:998-1003
ISSN: 1555-6255
0036-0295
DOI: 10.1134/s003602952108005x
Popis: A thermodynamic perturbation theory model is developed to take into account the additional charge–dipole contribution to the free energy of molten alkali halide systems, and it is used to describe the melt–crystal equilibria in binary salt mixtures with common anions. The liquidus lines in the binary phase diagrams LiF–NaF, LiF–KF, NaF–KF, NaF–CsF, and KF–CsF of the eutectic type are calculated. The error in describing the liquidus lines in the phase diagrams of the fluoride mixtures with the use of the tabulated ionic radii and polarizabilities is at most 15% as compared to the available FactSage data. The discrepancies between the calculated and published data become more noticeable for systems containing larger and more polarizable cations. The position of the eutectic equilibrium point is found to shift toward a low-melting-point component by 5–10%, and the eutectic point temperature is lightly overestimated in comparison with the experimental results and the FactSage data.
Databáze: OpenAIRE
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