中文摘要：

采用等温蒸发法研究了四元体系Li^＋，Na^＋//SO4^2-，CO3^2--H2O 288K介稳相平衡及平衡液相的密度、电导率、折光率、粘度和pH值，测定了该四元体系288K条件下介稳平衡溶液溶解度及物化性质．根据实验数据绘制了相应的介稳相图．研究发现：该体系介稳平衡中有复盐Na3Li（SO4）2·6H2O形成．其介稳相图中有3个共饱点，7条单变量曲线，平衡固相为：Li2SO4·H2O，Na2SO4，Na3Li（SO4）2·6H2O，Li2CO3，Na2CO3·10H2O．复盐Na3Li（SO4）2·6H2O和一水硫酸锂（Li2SO4·H2O）的结晶区较小，而Li2CO3的结晶区最大；该四元体系介稳平衡条件下未发现Na2SO4·10H2O的结晶区．

英文摘要：

An experimental study on metastable equilibria at 288 K in the quaternary system Li^＋, Na^＋//SO4^2- , CO3^2 -H2O was done by isothermal evaporation method. Metastable equilibrium solubilities and physico-chemical properties such as density, conductivity, pH, refractive index and viscosity of the solution were determined experimentally. The experimental results of the metastable equilibria show that the double salt [Na3Li（SO4）2·6H2O] forms in the quaternary system Li^＋, Na^＋//SO4^2-, CO3^2--H2O at 288 K. According to the experimental data, the metastable equilibrium phase diagram and the physico-chemical composition diagram were plotted. In the metastable phase diagram, the quaternary system has three invariant points, seven univariant curves, five fields of crystallization [Li2SO4·H2O, Na2SO4, Li2CO3, Na2CO3·10H20, Na3Li（SOa）2,6H2O]. The double salt Na3Li（SOa）2·6H2O and Li2SO4·H2O have smaller crystallization fields than the others. The crystallization field of Na2SO4·10H2O was not found in the metastable equilibria.