Miscibility Gaps in Fused Salts. Note XII. Systems Formed with Thallium (I) Halides and Lithium or Sodium Halides: the Ternary Li, Tl/Cl, I

Abstract

Demixing was investigated in the molten salt families formed with thallium (I) halides and lithium or sodium halides. Measurements were carried out on the twelve stable diagonals of the corresponding reciprocal ternary mixtures. Liquid-liquid equilibria were found in the three systems TlCl+LiF, TlBr+LiF and TlI+LiCl while in the two systems formed with Til and LiF or NaF measurements could not be carried out owing to the thermal instability of Til.

The reciprocal ternary Li, Tl/Cl, I exhibits demixing in a temperature range which is convenient for investigation: therefore the whole composition square was studied. The upper critical solution point of the gap lies along the stable diagonal at 734°C and x_LiCl = 0.58. The projection of the stratification lens occupies 38.8% of the composition square. Moreover an “a priori” prediction of the liquid-liquid equilibria was carried out by means of the conformal ionic solutiontheory.