三元体系硼酸钠-硼酸镁-水和硼酸钾-硼酸镁-水15℃时相平衡研究  

Phase equilibria in ternary systems sodium borate-magnesium borate-water and potassium borate-magnesium borate-water at 15℃

作　　者：董兴锋 王居奎 赵冬 王士强 郭亚飞 邓天龙 DONG Xing-feng;WANG Ju-kui;ZHAO Dong;WANG Shi-qiang;GUO Ya-fei;DENG Tian-long(Tianjin Key Laboratory of Marine Resources and Chemistry,College of Chemical Engineering andMaterial Science,Tianjin University of Science and Technology,Tianjin 300457,China)

机构地区：[1]天津科技大学化工与材料学院天津市海洋资源与化学重点实验室,天津300457

出　　处：《化学工程》2020年第5期54-58,共5页Chemical Engineering(China)

基　　金：国家自然科学基金资助项目(U170602,U1507109,U1607123,21773170);天津市自然科学基金资助项目(17JCYBJC19500)。

摘　　要：采用等温溶解平衡法,研究了三元体系硼酸钠-硼酸镁-水和硼酸钾-硼酸镁-水在15℃时固液相平衡,测定了2个体系的溶解度和平衡液相的密度、折光率、pH值。研究结果表明:两个三元体系15℃稳定相图中均有一个共饱点,2个两相区,1个三相区(分别为L+Na 2 B 4 O 7·10H 2 O+Mg 2 B 6 O 11·15H 2 O、L+K 2 B 4 O 7·4H 2 O+Mg 2 B 6 O 11·15H 2 O),体系存在3种固相为:Na 2 B 4 O 7·10H 2 O、K 2 B 4 O 7·4H 2 O和Mg 2 B 6 O 11·15H 2 O,无复盐或固溶体生成。溶液中硼酸钠(硼酸钾)对多水硼镁石有很强的盐析效应,液相的密度、折光率和pH值随溶液中硼酸钠(硼酸钾)质量分数的增加呈有规律的变化。Solid-liquid phase equilibria of the ternary systems(Na 2 B 4 O 7-Mg 2 B 6 O 11-H 2 O)and(K 2 B 4 O 7-Mg 2 B 6 O 11-H 2 O)at 15 o C were studied by an isothermal dissolution equilibrium method,and solubility of these two systems,density,refractive index,and pH value of the equilibrium solution were measured.The results show that these two systems at 288 K consists of one invariant point,two biphasic regions and one tirphasic regions corresponding to L+Na 2 B 4 O 7·10H 2 O+Mg 2 B 6 O 11·15H 2 O and L+K 2 B 4 O 7·4H 2 O+Mg 2 B 6 O 11·15H 2 O,three solid phases correspond to Na 2 B 4 O 7·10H 2 O,K 2 B 4 O 7·4H 2 O and Mg 2 B 6 O 11·15H 2 O,and neither double salts nor solid solutions form.The K 2 B 4 O 7 and Na 2 B 4 O 7 in solution both have a strong salting-out effect on inderite,and the density,refractive index,and pH value changed regularly with Na 2 B 4 O 7 or K 2 B 4 O 7 mass fraction increaing.

关 键 词：固液相平衡 溶解度 水盐体系相图 多水硼镁石 

分 类 号：TQ[化学工程]