Liquid-solid Equilibria in Quinary System Na+, K+, Mg2+//Cl−, NO−3 −H2O at 25 °C

The solubilities of the quinary system Na+, K+, Mg2+//Cl−, NO−3 -H2O and its two quaternary subsystems, Na+, K+, Mg2+//NO−3 -H2O and K+, Mg2+//Cl−, NO−3 -H2O, were studied by isothermal method at 25(C and their phase diagrams were plotted. In the equilibrium phase diagram of quaternary system Na+, K+, Mg2+//NO−3 -H2O, there are one invariant point, three univariant curves and three regions of crystallization with one salt: NaNO3, KNO3 and Mg(NO3)2·6H2O. In the equilibrium phase diagram of quaternary system K+, Mg2+//Cl−, NO−3 -H2O, there are three invariant points, seven univariant curves and five regions of crystallization with one salt: KNO3, KCl, Mg(NO3)2·6H2O, MgCl2·6H2O and KCl·MgCl2·6H2O. In the equilibrium phase diagram of the quinary system Na+, K+, Mg2+//Cl−, NO−3 -H2O, there are four invariant points, and seven regions of crystallization with one salt: NaCl, KCl, NaNO3, KCl·MgCl2·6H2O, KNO3, MgCl2·6H2O and Mg(NO3)2·6H2O.