CONTRIBUTION TO THE QUASI-CHEMICAL MODEL OF RECIPROCAL MOLTEN-SALT SOLUTIONS

The Gibbs energy of a reciprocal ternary molten salt solution may be estimated from the Gibbs energies of the pure components and of the constituent binary subsystems by means of solution models. The standard sublattice model often gives unsatisfactory results for systems with a large exchange Gibbs energy due to its neglect of the effect of non-random mixing upon the second-nearest-neighbor interactions. An extended quasichemical model is proposed to account for this effect without the introduction of adjustable parameters. Several reciprocal salt phase diagrams are calculated as examples.