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The solubilities and physicochemical properties, including density and pH, in the ternary system (LiBO + CaBO + HO) at (288.15 and 298.15) K were investigated using the isothermal dissolution equilibrium method. According to the experimental results of the ternary system at (288.15 and 298.15) K, the stable phase diagrams and the diagrams of physicochemical properties were plotted versus composition. In the phase diagrams of the ternary system at (288.15 and 298.15) K, there is one invariant point (LiBO·8HO + CaBO·6HO), two univariant isotherm dissolution curves, and two crystallization regions corresponding to lithium metaborate octahydrate (LiBO·8HO) and calcium metaborate hexahydrate (CaBO·6HO), respectively. This system at both temperatures belongs to hydrate type I classification and neither double salt nor solid solution were found. A comparison of the phase diagrams for the ternary system at (288.15 and 298.15) K shows that the numbers of solid phase and the minerals present are the same; the crystallized area of CaBO·6HO increased at the higher temperature, while that of LiBO·8HO decreased. The physicochemical properties (density and pH values) of the ternary system at the two temperatures change regularly with increasing lithium metaborate concentration. The calculated values of density using empirical equations of the ternary system are in good agreement with the experimental values. [ABSTRACT FROM AUTHOR]

Experimental studies on the metastable solubilities and the physicochemical properties including density, refractive index, conductivity, and pH values in the reciprocal quaternary system containing lithium, sodium, chloride, and sulfate at 273.15 K were determined with the method of isothermal evaporation. According to the experimental results, the dry-salt phase diagram, the water phase diagram, and the physicochemical properties versus composition were plotted. In the dry-salt phase diagram, there are three invariant points, seven solubility isotherm curves, and five crystallization fields corresponding to sodium chloride, mirabilite, lithium chloride dehydrate (LiCl·2H2O), lithium sulfate monohydrate, and a double salt (Li2SO4·3Na2SO4·12H2O). There were no solid solutions formed in the reciprocal quaternary system. The crystallizing region of mirabilite is the largest, while the region of LiCl·2H2O is the smallest with the highest concentration and a strong salting-out effect to NaCl and Li2SO4·H2O. When compared with the stable phase diagram at 273.15 K, the area of the phase region of mirabilite is enlarged significantly, while the areas of the phase regions of NaCl, Li2SO4·H2O, and Li2SO4·3Na2SO4·12H2O are decreased. The calculated values of densities and refractive index in the quaternary system with empirical equations are in good agreement with the experimental values. [ABSTRACT FROM AUTHOR]

Abstract: The solubility and the density in the aqueous ternary system (Li2SO4 +MgSO4 +H2O) at T =308.15K were determined by the isothermal evaporation. Our experimental results permitted the construction of the phase diagram and the plot of density against composition. It was found that there is one eutectic point for (Li2SO4 ·H2O+MgSO4 ·7H2O), two univariant curves, and two crystallization regions corresponding to lithium sulphate monohydrate (Li2SO4 ·H2O) and epsomite (MgSO4 ·7H2O). The system belongs to a simple co-saturated type, and neither double salts nor solid solution was found. Based on the Pitzer ion-interaction model and its extended HW models of aqueous electrolyte solution, the solubility of the ternary system at T =308.15K has been calculated. The predicted solubility agrees well with the experimental values. [Copyright &y& Elsevier]

Themetastable equilibrium solubilities and the physicochemicalproperties including refractive index, density, viscosity, conductivity,and pH for the aqueous reciprocal five-component system (Li + Na +K + Cl + SO4+ H2O) at 308.15 K were studiedusing the isothermal evaporation method. According to the experimentaldata, the dry-salt-phase diagram, sodium-phase diagram, water-phasediagram, and the diagrams of physicochemical properties versus compositionwere plotted. The dry-salt-phase diagram of the five-component systemincludes seven four-salt cosaturated points, fourteen univariant solubilitycurves, and eight crystallization zones all saturated with sodiumchloride. Three kinds of double salts of lithium salts (Db1, Li2SO4·3Na2SO4·12H2O; Db2, Li2SO4·Na2SO4; Db3, 2Li2SO4·Na2SO4·K2SO4) were found, and no solidsolution was formed in the metastable five-component system. Becausethe Pitzer mixing ion-interaction parameters containing lithium andsodium such as θLi,Na, ΨLi,Na,Cl, and ΨLi,Na,SO4at 308.15 K are scarce,the solubilities of the five-component system at 298.15 K were calculatedon the basis of Pitzer’s ion-interaction theory and the chemicalequilibrium Harvie–Møller–Weare model (HMW model).A comparison of the calculated phase diagram at 298.15 K and the experimentalphase diagram at 308.15 K was also carried out. [ABSTRACT FROM AUTHOR]