五元体系HCl-NaCl-CaCl_(2)-H_(3)BO_(3)-H_(2)O在298.15 K的Pitzer模型及其应用研究  

Pitzer thermodynamic model of the system HCl-NaCl-CaCl_(2)-H_(3)BO_(3)-H_(2)O at 298.15 K and its application

作　　者：李丹 孙帅琦 张涛 赵一慧 孟令宗 郭亚飞 邓天龙 LI Dan;SUN Shuaiqi;ZHANG Tao;ZHAO Yihui;MENG Lingzong;GUO Yafei;DENG Tianlong(School of Chemistry and Chemical Engineering,Linyi University,Linyi 276000,Shandong,China;College of Chemical Engineering and Materials Science,Tianjin University of Science and Technology,Tianjin 300457,China)

机构地区：[1]临沂大学化学化工学院,山东临沂276000 [2]天津科技大学化工与材料学院,天津300457

出　　处：《化工学报》2021年第6期3160-3169,共10页CIESC Journal

基　　金：山东省自然科学基金项目(ZR2020MB051);国家自然科学基金项目(22073068,U1507112)。

摘　　要：采用等温溶解法测定了三元体系CaCl_(2)-H_(3)BO_(3)-H_(2)O在298.15 K的溶解度和液相的折射率,该三元体系为简单共饱型,有1个共饱点,2条溶解度曲线和2个单盐结晶区,分别为CaCl_(2)·6H_(2)O和H_(3)BO_(3)。结合本文测定和文献中的溶解度数据,拟合了五元体系HCl-NaCl-CaCl_(2)-H_(3)BO_(3)-H_(2)O中含H_(3)BO_(3)的Pitzer参数,结合固相的溶解平衡常数,构建了该五元体系的Pitzer模型,并计算了该五元体系及其子体系的溶解度。根据Pitzer模型和计算相图,对氯化钠、氯化钙共存卤水中硼酸的分离进行了计算,获得了分离过程中的析盐顺序和卤水组成的变化规律。计算结果表明酸性条件下更容易实现H_(3)BO_(3)的分离。Solubility and refractive index in the ternary system CaCl_(2)-H_(3)BO_(3)-H_(2)O at 323.15 K were investigated with the dissolution equilibrium method.The phase diagram of this system consists of one invariant point,two univariant solubility curves and two single-salt crystallization regions for CaCl_(2)·6H_(2)O and H_(3)BO_(3).The Pitzer parameters containing H_(3)BO_(3) in the quinary system HCl-NaCl-CaCl_(2)-H_(3)BO_(3)-H_(2)O were fitted with the solubility data of ternary systems in this study and literatures.Combining the dissolution equilibrium constants of the solid phases in the quinary system,the Pitzer model of this system was constructed.The solubility in the quinary system and its subsystems were calculated with the Pitzer model.The phase diagrams and Pitzer model for the quaternary system were used to conduct computer simulation of H_(3)BO_(3) separation from brine with NaCl and CaCl_(2).The order of salt precipitation and changes in concentration of the brine were obtained.The calculation results show that the separation of H_(3)BO_(3)is easier to achieve under acidic conditions.

关 键 词：Pitzer热力学模型 硼酸 固液相平衡 溶解度 卤水分离 

分 类 号：TQ028.5[化学工程]