On the activity coefficients of components in molten salts

Abstract

The classical activity coefficient is shown to be unsuitable for a characterization of the interaction of components in molten salts. A better approach consists in the use of the „global" activity coefficient by which the model activity must be multiplied to give the thermodynamic activity, or of the suggested „internal"activity coefficient by which the concentration variable is multiplied in the expression for the model activity to become identical with the thermodynamic activity. The conclusions are illustrated on a LiF-NaCl melt. The interrelation between the global and the internal activity coefficients is analyzed. It is suggested that the internal activity coefficient may find application is statistical modelling of melt systems.