Phase equilibria in the Na,K,Mg,Ca∥SO4,Cl–H2O system at 50°С in the polyhalite crystallization region

Phase equilibria of the Na,K,Mg,Ca||SO4,Cl–H2O system at 50°С in the polyhalite (K2SO4 · MgSO4 · 2CaSO4 · 2H2O) crystallization region were studied using the translation method. Polyhalite was found to be involved, as an equilibrium phase of the title system at 50°С, in 17 invariant points, 36 monovariant curves, and 24 divariant fields. A fragment of equilibrium phase diagram of the title system in the polyhalite crystallization region was constructed.