摘要
采用等温溶解平衡法研究四元体系硼酸锂-硼酸钾-硼酸镁-水15℃时固液相平衡,测定了体系溶解度和平衡液相的密度、折光率.研究发现:该体系15℃稳定相图中包含一个共饱点(L+Li_(2)B_(4)O_(7)·3H_(2)O+K_(2)B_(4)O_(7)·4H_(2)O+Mg_(2)B_(6)O_(11)·15H_(2)O),其液相组成为w(Li_(2)B_(4)O_(7))1.31%、w(K_(2)B_(4)O_(7))10.57%、w(MgB_(4)O_(7))0.05%;3个固相结晶区为Li_(2)B_(4)O_(7)·3H_(2)O、K_(2)B_(4)O_(7)·4 H_(2)O、Mg_(2)B_(6)O_(11)·15H_(2)O,体系无复盐或固溶体生成.溶液中硼酸锂、硼酸钾对多水硼镁石有很强的盐析效应,液相的密度和折光率随溶液中硼酸锂浓度的增加呈有规律的变化.采用经验公式对密度和折光率进行关联,计算值和实验值吻合较好.
The phase equilibrium of the quaternary system of lithium borate-potassium borate-magnesium borate-water has been studied at 15℃with the method of isothermal solution saturation.Solubility,density and refractive index were analyzed.Phase diagram of this system contains one invariant point(L+Li_(2)B_(4)O_(7)·3H_(2)O+K_(2)B_(4)O_(7)·4H_(2)O+Mg_(2)B_(6)O_(11)·15H_(2)O)whose liquid compositions are w(Li2B4O7)1.31%,w(K2B4O7)10.57%,w(MgB4O7)0.05%;and three crystallization regions correspond to Li_(2)B_(4)O_(7)·3H_(2)O,K_(2)B_(4)O_(7)·4H_(2)O and Mg_(2)B6O_(11)·15H_(2)O,respectively.Neither double salts nor solid solutions formed in this system,and both K2B4O7 and Li2B4O7 in the solution have a strong salting-out effect on inderite.The solution density and refractive index of the quaternary system changed regularly with the increase of Li_(2)B_(4)O_(7) concentration.The density and refractive index calculated with empirical equations can well match those in the experiment.
作者
郑志伟
顾鹏
王士强
郭亚飞
邓天龙
ZHENG Zhiwei;GU Peng;WANG Shiqiang;GUO Yafei;DENG Tianlong(College of Chemical Engineering and Materials Science,Tianjin University of Science&Technology,Tianjin 300457,China;Tianjin Key Laboratory of Marine Resources and Chemistry,Tianjin 300457,China)
出处
《天津科技大学学报》
CAS
2021年第2期15-19,共5页
Journal of Tianjin University of Science & Technology
基金
国家自然科学基金资助项目(U1707602,U1507109)
天津市自然科学基金资助项目(17JCYBJC19500)。
关键词
固液相平衡
溶解度
水盐体系
多水硼镁石
stable phase equilibrium
solubility
salt-water system
inderite
