三元体系Na2B4O7-MgB4O7-H2O273K相平衡

摘要

采用等温溶解平衡法研究了三元体系Na2B4O7-MgB4O7-H2O 273 K稳定相平衡关系.测定了该体系平衡时各组分的溶解度,根据实验数据和固相组成绘制了三元体系Na2B4O7-MgB4O7-H2O 273 K等温相图.实验结果表明:该体系组分之间没有形成复盐和固溶体,属于简单共饱和型体系;体系的稳定相图由1个共饱点,2条单变量曲线,2个固相结晶区组成,结晶区分别对应Na2B4O7·10H20和MgB4O7·9H2O.文中还对该三元体系在不同温度时的稳定相图作了对比分析和讨论.%The phase equilibrium in ternary system Na2B4O7-MgB4O7-H2O at 273 K was studied using isothermal solubility equilibrium method.The solubilities of the components in the system were measured.Based on the determined equilibrium data and the corresponding equilibrium solid phase,the isothermal phase diagram of the ternary system can be obtained.The experimental results show that the ternary system is simple total saturated type,and no double salt and solid solution are found.Besides,the phase diagram is constituted of a eutectic point,two univariant solubility curves,and two solid phase crystalline regions.The two equilibrium solid phases corresponding to the system are Na2B4O7 · 10H2O and MgB4O7 · 9H2O.Furthermore,the phase diagrams at different temperatures were compared.