Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

ABSTRACT

Solubilities, densities, and refractive indices for the salt-water ternary system (LiCl + LiBO2 + H2O) at T = 288.15 K and 298.15 K and p = 0.1 MPa were determined using the isothermal dissolution equilibrium method. According to the experimental data at two temperatures, the phase diagrams and the diagrams of densities and refractive indices versus lithium chloride composition in the solution were plotted, respectively. In the phase diagrams at 288.15 K and 298.15 K, in all there are three crystallizing regions corresponding to lithium metaborate octahydrate (LiBO2*8H2O, Lb8), lithium metaborate dihydrate (LiBO2*2H2O, Lb2), and lithium chloride monohydrate (LiCl*H2O, Lc1), three univariant curves and two invariant points corresponding to (Lb8 + Lb2) and (Lb2 + Lc1). It was found that there are two kinds of hydrates for lithium metaborates (Lb8 and Lb2) formed at both termperatures, and the hydrate for lithium metaborate belongs to hydrate type II. Neither double salts nor solid solutions were found. A comparison of the phase diagrams at two temperatures shows that the areas of the crystalline regions of Lb8 and Lc1 are decreased and that of Lb2 is increased with increasing temperature. The density and refractive index in the ternary system at two temperatures change regularly with the increasing LiCl mass fraction in the solution to reach the maximum values in the ternary-invariant-point. The correlation equations of density and refractive index were used, and the calculated results agree well with the experimental data.