Coupled Phase Diagram/Thermodynamic Analysis of the Nine Common‐Ion Binary Systems Involving the Carbonates and Sulfates of Lithium, Sodium, and Potassium

The thermodynamic properties and phase diagrams of the nine common‐ion binary systems of alkali carbonates and sulfates have been critically evaluated by the technique of computer‐assisted simultaneous optimization. Coefficients of series expansions for the excess thermodynamic properties of all phases have been found which can be used to reproduce the thermodynamic properties and to calculate the phase diagrams within experimental error limits. Henrian activity coefficients of dilute solid solutions and Gibbs energies of formation of compounds have also been determined. The resultant calculated thermodynamic properties and phase diagrams are self‐consistent, and represent the best estimates which can be made based on currently available data. A consistent set of values for the thermodynamic properties of the pure salts has also been adopted, and some thermodynamic properties of the pure alkali carbonates and sulfates have been revised.