A Corresponding States Method for the Prediction of Surface Tension of Molten Carbonate Mixtures

A methodology using the theory of corresponding states has been developed to predict the surface tension of molten alkali carbonate mixtures and alkali-alkaline-earth carbonate mixtures as a function of composition and temperature. To correlate the dimensionless surface tension, the parameters for pure components are determined. The potential parameters of pure salt are defined at the melting point with respect to a standard salt. A size-dependent mixing rule is proposed to predict properties of a mixture based on the heats of mixing of molten salts. Selected experimental data of binary mixtures at 40-60 mol % Li are used to fit key parameters. The correlations developed by this method provide very good accuracy for both binary and ternary alkali carbonate mixtures (within 1.5% deviation for ternary alkali carbonates). In alkali-alkaline-earth carbonate mixtures, a similar accuracy is only achieved in the low alkaline-earth fraction range. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3371415] All rights reserved.