LAUSR

Abstract Phase diagrams of aqueous saline systems constitute the cornerstone for chemical industry of inorganic salts. Although quite a few of theoretical models have been proposed, most of them rely on the empirical parameters that are determined in prior by fitting experimental data. Herein, we propose a new molecular thermodynamic approach for predicting the phase diagrams of aqueous saline solutions. This approach is developed relying on the molecular interaction and the assumption that the ion dissolution in solvent is analogous to gas adsorption. By means of this approach, the phase diagrams of several typical types of ternary aqueous saline solutions are predicted, by combining classical density functional theory with the solubility data of one single salt. The predictions have overall good agreements with the corresponding experimental measurement. The developed approach is simple yet generic, and it can be extended to investigate phase diagrams for multi-salt aqueous solutions and other related systems.