298.15 K下KCl-RbCl-H_2O体系热力学性质的等压研究

Isopiestic Studies on Thermodynamic Properties for KCl-RbCl-H_2O System at 298.15 K

用等压法测定了298.15 K下氯化物型含铷卤水的三元子体系KCl-Rb Cl-H2O的等压平衡浓度,混合溶液的离子强度范围从0.5 mol·kg-1到4.9 mol·kg-1。由实验结果计算了混合溶液的渗透系数、水活度,根据Pitzer离子相互作用模型对实验结果进行参数化研究,拟合得到了描述KCl-Rb Cl-H2O混合溶液中离子间相互作用的Pitzer混合参数。用Pitzer模型计算的混合溶液的渗透系数、水活度与实验结果相一致。

As a subsystem of chloride type and rubidium contained brines, isopiestic molalities for the ter- nary KCl -RbCl - H2O system at 298.15 K have been measured isopiestieally. The investigated ionic strengths of ternary mixing solutions were from 0.5 to 4.9 mol. kg-1. Osmotic coefficients and activities of water have been calculated from the measurements. On the basis of the experimental osmotic coefficients Pitzer mixing parameters which describe interactions between different ions have been calculated by using multiple regression method. The measured osmotic coefficients data and water activity data are in good agreements with those calculated by the Pitzer model.