Calculation of thermodynamic properties of LiFAlF3, NaFAlF3 and KFAlF3

Abstract The scheme of dissociation of cryolite in NaFAlF 3 melts is proposed and applied to the LiFAlF 3 and KFAlF 3 systems. The constants and enthalpies of dissociation for alkali-cryolites are evaluated from experimental data. The mole fractions of each proposed species at 1298K in these three melt systems are calculated, and the variation of alumina solubility in alkali-cryolite can be explained on the basis of the ionic structure for the M F- AlF 3 ( M : Li, Na and K) melts. The thermodynamic properties and liquidus data of M F-AlF 3 systems are calculated by using the selected evaluated parameters. Some results are compared with experimental values.