273.15K下Li_2B_4O_7-LiCl-H_2O体系热力学性质的等压研究及离子作用模型  

Isopiestic Studies on Thermodynamic Properties and Representation with Ion-interaction Model for the Li_2B_4O_7-LiCl-H_2O System at 273.15K

作　　者：杨吉民[1] 姚燕[2] 

机构地区：[1]临沂师范学院化学系,临沂276005 [2]中国科学院青海盐湖研究所,西宁810008

出　　处：《化学学报》2007年第11期1089-1093,共5页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20373084);临沂师范学院科研基金(No.XJS04064)资助项目.

摘　　要：用等压法研究了273.15K下Li2B4O7-LiCl-H2O体系不同质量摩尔浓度分数的等压平衡浓度和水活度;计算了LiCl和Li2B4O7混合盐溶液的渗透系数等热力学性质.用273.15K下的实验数据对Pitzer离子相互作用模型进行了参数化研究,拟合求取了273.15K下Pitzer离子相互作用参数,用获得的参数计算了LiCl和Li2B4O7在Li2B4O7-LiCl-H2O体系中的活度系数.273.15K下由相应的Pitzer模型计算的渗透系数值与实验结果一致.这对完善含锂、硼盐湖卤水体系的热力学模型具有重要意义.The isopiestic molalities and the water activities have been determined at 273.15 K for the Li2B4O7-LiCl-H2O system by isopiestic method, and the vapor pressures and the osmotic coefficient have been calculated from the measurements. The experimental data have been represented by the different forms of the ion interaction model based on the primary Pitzer model of osmotic coefficient. The Pitzer ion interaction parameters were evaluated from recent measurements by using multiple regression and iterative methods. The activity coefficients of LiC1 and LiaB4O7 for the system LiaB4O7-LiCl-H2O were calculated by the ion interaction model parameterized at low concentrations. The experimental data of osmotic coefficients measured and calculated by using the Pitzer model are in reasonable agreements. These studies are useful for improving the thermodynamic model for salt lake brine complex systems containing lithium and borate.

关 键 词：Li2B4O7-LiCl-H2O体系 等压法 渗透系数 PITZER模型 

分 类 号：O642[理学—物理化学]