Phase Equilibria in the Ternary System MgCl2 + SrCl2 + H2O and the Quaternary Systems NaCl + MgCl2 + SrCl2 + H2O and KCl + MgCl2 + SrCl2 + H2O at 373 K

The stable phase equilibria of the ternary system MgCl2 + SrCl2 + H2O and the two quaternary systems NaCl+ MgCl2 + SrCl2 + H2O and KCl + MgCl2 + SrCl2 + H2O at 373 K were investigated using an isothermal method. Based on the experimental results, the isothermal solubility diagram of the ternary system MgCl2 + SrCl2 + H2O, and the solubility diagrams and water content diagrams of the two quaternary systems were constructed. The results show that the ternary system MgCl2 + SrCl2 + H2O at 373 K belongs to the simple co-saturated type without complex salt or solid solution. There are two invariant points, three univariant curves and three crystallization fields corresponding to SrCl2 center dot 2H(2)O, SrCl2 .H2O and MgCl2 center dot 6H(2)O.The quaternary system NaCl+ MgCl2 + SrCl2 + H2O at 373 K is of the simple co-saturated type and no complex salt or solid solution are found. The phase diagram contains two invariant points, five univariant curves and four crystallization fields (where the solids are NaCl, MgCl2 center dot 6H(2)O, SrCl2 center dot H-2O and SrCl2 center dot 2H(2)O). The system KCl + MgCl2 + SrCl2 + H2O at 373 K has a double salt named carnallite (KCl center dot MgCl2 center dot 6H(2)O) without solid solution formation. The phase diagram contains three invariant points, seven univariant curves and five crystallization fields (where the solids are KCl, MgCl2 center dot 6H(2)O, SrCl2 center dot H-2 O, SrCl2 center dot 2H(2)O and KCl center dot MgCl2 center dot 6H(2)O).