Abstract: Pitzer-Li equation is employed for the evaluation of the thermodyna-mic properties of aqueous NaCl up to 823 K and 100 MPa, with maximum concentration of NaCl up to 65.2 wt%, which happens to be the saturation solubility of NaCl at the triple point. Thermodynamic properties evaluated include water activity, mean ionic activity coefficient of NaCl and Gibbs free energy. The calculated values correlate quite well with experimental data obtained. Parameters of short-range interparticle interaction (w) and Gibbs energies of NaCl fusion (△sG20/RT) over 623-823 K and up to 100 MPa required for such calculations are also presented. The changes of w with changes in temperatures are discussed. A reference pressure method is introduced to calculate the values of d, ρ and Ax for the Debye-Huckel term in PL equation at all lower pressures over the 623-823 K range and the reference pressures P, at different temperatures are also given.

摘要： 本文将(I)报中提出的简易方程式推广应用到823K和100MPa的NaCl水溶液,NaCl的最高浓度达65.2wt%(三相点时的饱和溶解度)下热力学性质的计算.这些热力学性质包括溶液中水的活度、氯化钠的平均离子活度系数、溶液的Gibbs自由能,计算值与实验值吻合较好.文中列出了不同温度压力下的w和△_8G_2~0/RT值及其变化曲线、和本文提出的参考压力值P_r,为高温高压下电解质水溶液的研究作了初步的探索.