化学学报 ›› 2007, Vol. 65 ›› Issue (11): 1089-1093. 上一篇    

研究简报

273.15 K下Li2B4O7-LiCl-H2O体系热力学性质的等压研究及离子作用模型

杨吉民*,1, 姚燕2   

  1. (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)
  • 投稿日期:2006-09-19 修回日期:2007-01-08 发布日期:2007-06-14
  • 通讯作者: 杨吉民

Isopiestic Studies on Thermodynamic Properties and Representation with Ion-interaction Model for the Li2B4O7-LiCl-H2O System at 273.15 K

YANG Ji-Min*,1; YAO Yan2   

  1. (1 Department of Chemistry, Linyi Normal University, Linyi 276005)
    (2 Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008 )
  • Received:2006-09-19 Revised:2007-01-08 Published:2007-06-14
  • Contact: YANG Ji-Min

用等压法研究了273.15 K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273.15 K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273.15 K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. 273.15 K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.

关键词: Li2B4O7-LiCl-H2O体系, 等压法, 渗透系数, Pitzer模型

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 re-cent measurements by using multiple regression and iterative methods. The activity coefficients of LiCl and Li2B4O7 for the system Li2B4O7-LiCl-H2O were calculated by the ion interac-tion 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.

Key words: Li2B4O7-LiCl-H2O system, isopiestic method, osmotic coefficient, Pitzer model