The phase and density diagrams of the systems MgCl2–MgB4O7–H2O and KCl–K2B4O7–H2O at 273 K

The method of isothermal dissolution was used to study the solubilities and the densities of the two systems MgCl2–MgB4O7–H2O and KCl–K2B4O7–H2O at 273 K. By the X-ray diffraction the equilibrium solids were determined. The phase diagrams and density versus composition diagrams of the systems MgCl2–MgB4O7–H2O and KCl–K2B4O7–H2O at 273 K were plotted. The both diagrams are consisted of one invariant, two stable solubility isothermal curves and two crystallization fields. The crystallization fields for the system MgCl2–MgB4O7–H2O corresponds to MgB4O7 · 9H2O and MgCl2 · 6H2O. Those for the system KCl–K2B4O7–H2O corresponds to K2B4O7 · 4H2O and KCl.