Na_2B_4O_7-NaBr-Na_2SO_4-H_2O四元体系348K相平衡研究  

Study on phase equilibria in Na_2B_4O_7-NaBr-Na_2SO_4-H_2O quaternary system at 348 K

作　　者：宁慧逸[1] 桑世华[1] 王丹[1] 曾晓晓[1] 

机构地区：[1]成都理工大学材料与化学化工学院,四川成都610059

出　　处：《化学工程》2012年第4期27-30,共4页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(40973047);四川省杰出青年学科带头人培养资助计划资助项目(08ZQ026-017);教育部新世纪优秀人才资助计划资助项目(NCET-07-0125)

摘　　要：采用等温溶解平衡法研究Na2B4O7-NaBr-Na2SO4-H2O四元体系在348 K的相平衡关系,测定了平衡液相的溶解度和密度。根据实验数据绘制相应相图。该四元体系相图中有1个共饱点E,3条单变量曲线E1E,E2E,E3E,3个结晶区的平衡固相分别为:NaBr,Na2SO4和Na2B4O7·5H2O。研究结果表明:该四元体系无复盐和固溶体生成,属于简单四元体系,NaBr对Na2B4O7·5H2O和Na2SO4有较强的盐析作用。并对NaBr和Na2B4O7在不同温度下含有的结晶水数进行了对比分析,简要讨论了密度变化规律。The solubilities and densities of solution in Na2B4O7-NaBr-Na2SO4-H2O quaternary system at 348 K were determined by isothermal equilibrium method.Based on the experimental data,the equilibrium phase diagram was plotted,which consists of one invariant E,three univariant curves（E1E,E2E and E3E）,and three crystallization fields corresponding to NaBr,Na2SO4 and Na2B4O7·5H2O.The experimental results indicate that the quaternary system is of simple eutectic type and no double salt and solid solution,and sodium bromide has the salting-out effect on Na2B4O7·5H2O and Na2SO4.The densities transformation rules were discussed.

关 键 词：水盐体系 相平衡 硼酸盐 

分 类 号：O642.42[理学—物理化学]