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

ABSTRACT

The solubilities of ternary system (CaCl2 + SrCl2 + H2O) and quaternary system (NaCl + CaCl2 + SrCl2 + H2O) at T =288.15 K and p = 0.1 MPa were investigated experimentally with the method of isothermal dissolution equilibrium, and the corresponding phase diagrams were plotted. Compared with the phase diagram of the ternary system (CaCl2 + SrCl2 + H2O) at 291.15 K which only includes one crystallization region of a completely miscible solid solution (Ca,Sr)Cl2*6H2O, there were also found the pure single salts CaCl2*6H2O and SrCl2*6H2O in the ternary system at 288.15 K besides the crystallization of solid solution (Ca,Sr)Cl2*6H2O. The solid solution of (Ca,Sr)Cl2*6H2O was also formed in the quaternary system (NaCl + CaCl2 + SrCl2 + H2O) at 288.15 K, and there were four crystalline fields in the quaternary system, which correspond to single salts NaCl, SrCl2*6H2O, CaCl2*6H2O and the solid solution (Ca,Sr)Cl2*6H2O, respectively. On the basis of the analyses of the phase diagrams of (CaCl2 + SrCl2 + H2O) and (NaCl + CaCl2 + SrCl2 + H2O) at 288.15 K, CaCl2*6H2O and SrCl2*6H2O can be separated from each other through avoiding crystallizing in the solid solution crystallization region in the systems, and SrCl2*6H2O and NaCl can be produced using CaCl2 as salting-out agent directly.