Tianjin Key Laboratory of Marine Resources and ChemistryĬollege of Marine and Environmental Sciences, * PHASE EQUILIBRIUM AND PHASE DIAGRAM FOR The solution density and refractive index of the quaternary system change regularly with the increase of K+ concentration. These results indicate that potassium sulfate is easy to saturate and crystallize from solution and that lithium chloride has a high solubility during isothermal evaporation. The crystallization area of potassium sulfate (K2SO4) is the largest, and the crystallized zone of lithium chloride monohydrate (LiCl∙H2O) is the smallest.
![plutonic ternary diagram plutonic ternary diagram](https://geea.lyellcollection.org/content/geochem/17/2/63/F4.large.jpg)
In the phase diagrams of the system there are three invariant points, seven univariant isotherm dissolution curves, and five crystallization regions corresponding to lithium chloride monohydrate (LiCl∙H2O), lithium sulfate monohydrate (Li2SO4∙H2O), potassium chloride (KCl), potassium sulfate (K2SO4), and double salt lithium potassium sulfate (Li2SO4∙K2SO4), where the double salt lithium potassium sulfate (Li2SO4∙K2SO4) is an incongruent double salt. The phase and physicochemical properties diagrams of the quaternary system (Li+, K+//Cl-, SO42-H2O) at 288.15 K were constructed using the solubilities, densities, and refractive indices measured.