Solid-Liquid Phase Equilibrium of the Quaternary System (CaCl2 + CaSO4 + CaB6O10 + H2O) at 288.15 K and Atmospheric Pressure

The solid-liquid phase equilibrium of the quaternary system (CaCl2 + CaSO4 + CaB6O10 + H2O) at 288.15 K and atmospheric pressure were investigated with the method of isothermal dissolution equilibrium. The dry-salt, water-phase diagrams and physicochemical properties including refractive index, density and pH versus composition diagrams were plotted on the basis of the experimental data. In the dry-salt diagram of the quaternary system, there is one invariant point, three solubility curves and three crystallization regions corresponding to single salts antarcticite (CaCl2 center dot 6H(2)O, Ant), gypsum (CaSO4 center dot 2H(2)O, Gy) and gowerite (CaB6O10 center dot 5H(2)O, Gow). No double salt or solid solution was formed. The area of crystallization region of gypsum is the largest, and that of antarcticite is the smallest. In addition, the physicochemical properties showed a regular change with the Janecke index value of J(CaCl2).