采用等温溶解平衡法研究了三元体系KCl-K2B4O7-H2O在323K时的稳定相平衡关系及稳定平衡液相的密度,测定了该三元体系稳定平衡溶液溶解度和密度。研究发现:该三元体系为简单共饱和型.无复盐及固溶体形成。根据溶解度数据绘制了相图,相图中有1个三元共饱点、2条单变量曲线、2个结晶相区,即氯化钾(KCl)结晶区和四硼酸钾(K2B4O7·4H2O)结晶区;平衡固相为KCl和K2B4O7·4H2O。由相图可以看出,KCl对K2B4O7有较强的盐析作用。
An experimental study on phase equilibria at 323 K in the ternary system KCl-K2B4O7-H2O was made by isother- mal method.Phase equilibrium solubilities and densities of the solution were determined.Experimental results showed that the ternary system was a type of simple common saturation without double salt and solid solution.On the basis of solubility data, the phase diagram was plotted,which consisted of one invariant point, two univariant curves, and two crystallization zones,i.e. KCl-and K2B4O7.4H2O-erystallization zones.The equilibrium solid phase was KC1 and K2B4O7·4H2O.The phase diagram showed that KCl had the salting-out effect on K2B4O7.