Physicochemical Properties of the (LiF + CaF₂)_eut + LaF₃ System: Phase Equilibria, Volume Properties, Electrical Conductivity, and Surface Tension

Abstract

The physicochemical behavior of the molten system (LiF (1) + CaF 2 (2)) eut + LaF 3 (3) has been studied and the phase equilibria, density and volume properties, electrical conductivity, and surface tension have been selected for investigation. Well-established methods for determination of these physicochemical properties of molten salts have been used, such as thermal analysis, the Archimedean method of hydrostatic weighing, and the phase shift and maximum bubble pressure methods. A significant change in all investigated properties was detected in the region of x 3 = 0.04–0.06. In regard to phase equilibria, this region is close to and may contain the eutectic point; in volumetric properties, the initial volume contraction (on increasing mol %) starts to reverse. A sharp change of electrical conductivity reflects the changes in ionic composition, and surface tension also shows different behavior below and above this region.