Solubility measurement and solid-liquid equilibrium model for the ternary system MgBr2 + MgSO4 + H2O at 288.15 K

The solubility of magnesium minerals and the refractive index of the ternary system MgBr2 + MgSO4 + H2O at 288.15 K were investigated using an isothermal dissolution method. It was found that there are two invariant points in the phase diagram and the solubility isotherm of this ternary system consists of three branches, corresponding to equilibrium crystallization of Epsomite (MgSO4·7H2O, Eps), hexahydrite (MgSO4·6H2O, Hex) and magnesium bromide hexahydrate (MgBr2·6H2O, Mb). Neither solid solutions nor double salts were found. The refractive indices calculated from empirical equation are i...