【作者】 杨文忠； 王晓云； 刘瑛； 尹晓爽；

【机构】 南京工业大学理学院；

【摘要】 采用等温溶解平衡法研究了四元体系Na⁺,Ca²⁺//Cl^-,SO₄^2--H₂O在25℃的介稳相平衡关系,测定了该温度下四元体系中液相的溶解度及其主要物化性质。根据实验数据,绘制了四元体系干盐图和水图,同时绘制了该体系的物化性质-组成图。四元体系Na⁺,Ca²⁺//Cl^-,SO₄^2--H₂O在25℃时的介稳相图属于简单型,该体系在25℃下有2个共饱和点,6条溶解度曲线和4个结晶相区,其平衡相区分别为NaCl、Na₂SO₄、CaSO₄·2H₂O和CaCl₂·6H₂O结晶区,介稳平衡溶液的密度和电导率呈现规律性变化,均随着SO₄^2-的含量呈现一致的变化,并且和该体系该温度的水图的变化相吻合。更多还原

【Abstract】 The metastable phase equilibrium in the quaternary system Na⁺,Ca²⁺//Cl^-,SO₄^2--H₂O at298 K was studied by using isothermal solution equilibrium method in the paper.The solubilities and physicochemical properties（density and conductivity） of the metastable system were determined at the same temperature.The phase diagrams of the ternary system and the dry-salt system were drawn according to the experimental data.The physicochemical composition diagram was plotted,respectively.The experimental results show that the quaternary system Na⁺,Ca²⁺//Cl^-,SO₄^2--H₂O at 298 K was of simple eutectic type system.In the matestable phase diagram of the ternary system,there existed two invariant points,six solubility curves and four crystallization zones corresponding to NaCl,Na₂SO₄,CaSO₄·2H₂O and CaCl₂·6H₂O.From the diagrams of physicochemical properties versus compositions in the metastable system,the density and conductivity presented the regular change with the SO₄^2- Janecke index,and the change was identical with the trend of dry-salt diagram in the system at 298 K.更多还原