【摘要】 采用等温蒸发法研究了K2CO3-KCl-K2B4O7-H2O四元体系298 K介稳平衡相关系,并测定了该体系达介稳平衡时液相的密度、折光率和pH值等物化性质。根据实验数据,绘制了该体系298 K的介稳相图及物化性质-组成图。结果表明:该四元体系属简单共饱型,无复盐或固溶体形成;其溶解度等温图含有一个共饱点、三条单变量曲线和3个结晶相区。3个结晶相区分别对应于K2B4O7.4H2O,K2CO3.32 H2O和KCl。共饱点的平衡液相组成为w(K2CO3)=51.57%,w(KCl)=1.09%,w(K2B4O7)=1.29%,所对应的平衡固相为K2CO3.32 H2O+KCl+K2B4O7.4H2O。更多还原

【Abstract】 The metastable phase equilibrium in K2CO3-KCl-K2B4O7-H2O quaternary system was studied with isothermal evaporation method at 298 K.The solubility and physico-chemical properties(density,refractive index and pH value) of the metastable equilibrium solutions were determined at the same temperature.According to the experimental data,the phase diagram and physico-chemical property-composition diagrams of the quaternary system were plotted.This quaternary system is a simple eutectic type,and no double salt or solid solution was found.The isotherm diagram consists of one invariant point,three univariant curves and three crystallization fields that correspond to K2B4O7·4H2O,K2CO3·3/2H2O and KCl.The composition of the metastable equilibrium solution at the invariant point is: w(K2CO3)=51.57%,w(KCl)=1.09%,and w(K2B4O7)=1.29%.更多还原