采用等温蒸发法研究了五元体系Li+、K+//CO32-、SO42-、B4O72-、H2O 273 K介稳相平衡关系,测定了它们在273 K条件下的介稳平衡的溶解度和溶液密度,根据实验数据绘制了相应的该五元体系在273 K条件下Li2CO3饱和的介稳平衡相图(干盐投影图和水含量图)。研究结果表明该五元体系介稳平衡中有复盐K2SO4·Li2SO4生成,其低温273 K时介稳相图中有4个共饱点和9条单变量曲线,6个 Li2CO3饱和的结晶区分别为 LiBO2·8H2O、K2B4O7·4H2O、K2CO3·3/2H2O、K2SO4、Li2SO4·H2O和复盐K2SO4·Li2SO4。对该五元体系在288 K和273 K时的介稳平衡相图进行了比较和讨论。
An experimental study on metastable equilibria of the quinary system Li+, K+//CO32-, SO42-, B4O72--H2O at 273 K was made by isothermal evaporation method. Metastable equilibrium solubilities and densities of the solution were determined experimentally. Using the experimental data, the metastable equilibrium phase diagrams (dry-salt phase diagram and water content diagram) were plotted. The experimental results show that the double salt K2SO4·Li2SO4 is formed in the quinary system Li+, K+//CO32-, SO42-, B4O72--H2O at 273 K. And it was found that the metastable equilibrium phase diagram has four invariant points, nine univariant curves, and six fields of crystallization saturated with Li2CO3 corresponding to LiBO2·8H2O, K2B4O7·4H2O , K2CO3·3/2H2O,K2SO4,K2SO4·Li2SO4 and Li2SO4·H2O. The comparison and discussion between the metastable phase diagram for the quinary system Li+, K+//CO32-, SO42-, B4O72--H2O at 273 K and at 288 K were made.