三元体系Li+, Cs+//SO42--H2O 298 K稳定相平衡研究

三元体系Li⁺, Cs⁺//SO₄^2--H₂O 298 K稳定相平衡研究

摘要: 采用等温溶解平衡法研究了三元体系Li⁺，Cs⁺//SO₄^2--H₂O 298 K稳定相平衡关系。测定了平衡液相各组分溶解度、密度和折光率数据并绘制了相应的等温平衡相图、密度-组成图和折光率-组成图。结果表明：该体系属于复杂体系，有复盐3Li₂SO₄·Cs₂SO₄·2H₂O和Li₂SO₄·Cs₂SO₄形成；其稳定相图由4个固相结晶区、4条单变量曲线和3个相称共饱点组成，4个固相结晶区分别对应Li₂SO₄·H₂O、3Li₂SO₄·Cs₂SO₄·2H₂O、Li₂SO₄·Cs₂SO₄和Cs₂SO₄。

Abstract: The stable phase equilibria of the ternary system Li⁺, Cs⁺//SO₄^2--H₂O at 298 K were studied using isothermal solubility equilibrium method. The solubility, density and refractive index of the equilibrium liquid phase were measured and the corresponding equilibrium phase diagram, density-composition diagram and refractive index-composition diagram were plotted. The results indicated that the system is a complex one with the formation of double salts, such as 3Li₂SO₄·Cs₂SO₄·2H₂O and Li₂SO₄·Cs₂SO₄. The stable phase diagram consists of four solid phase crystallization zones, four univariate curves and three commensurate invariant points. The four solid phase crystallization zones correspond to the salts of Li₂SO₄·H₂O, 3Li₂SO₄·Cs₂SO₄·2H₂O, Li₂SO₄·Cs₂SO₄ and Cs₂SO₄.