Solid-Liquid Equilibria in the Quaternary Systems KCl-MgCl2-SrCl2-H2O and NaCl-KCl-SrCl2-H2O at 348 K

摘要

Solid-liquid equilibria in the quaternary systems KCl-MgCl2-SrCl2-H2O and NaCl-KCl-SrCl2-H2O at 348 K were measured by the isothermal solution saturation method. The composition of the equilibrium solid phase, solubilities of salts, and densities of saturated solution in the two systems were determined. Phase diagrams, water content diagrams and solution density diagrams of quaternary systems were plotted according to experimental data. The phase diagram of the quaternary system NaCl-KCl-SrCl2-H2O has one invariant point, three univariant curves as the boundary of NaCl, KCl and SrCl2 2H(2)O. This phase diagrams were simple co-saturation type without complex salt and solid solution. For the quaternary system KCl-MgCl2-SrCl2-H2O, one complex salt KCl MgCl2 6H(2)O (Car) had been found in this system, consisted of five univariant curves, two invariant points and four crystallization regions of MgCl2 6H(2)O (Bis), KCl, SrCl2 2H(2)O and KCl MgCl2 6H(2)O. And the densities transformation rules were simply discussed. Simultaneously, the solubilities and densities data in invariant point of the quaternary system NaCl-KCl-SrCl2-H2O had been compared with the experimental data of previous researchers.