高温高压下流体中电解质活度系数的确定

Determination of Mean Molar Activity Coefficients of Electrolytes In Aqueous Solutions At High Temperature and Pressure

高温高压下流体中电解质的活度系数在地球化学领域有着广泛的应用。本文实验测量了１００～５００℃、０－１１～１２ＧＰａ 下０．０１ ｍｏｌＬＫＣｌ 溶液的电导率，并利用Ｈüｃｋｅｌ 方程由实验确定的摩尔电导和极限摩尔电导计算出了ＫＣｌ 的平均摩尔活度系数。平均摩尔活度系数随温度升高而减小，随压力升高而增大，而在高温高压下随温度压力的升高几乎保持恒定。

The activity coefficients of electrolytes in aqueous solutions at elevated temperatures and pressures are important in many geochemical applications. The electrical conductivities of 0.01mol/L KCl solutions were measured at temperatures from 100℃ to 500℃ and pressures from 0.1 MPa to 1.2 MPa. The activitiy of KCl were calculated using Hǖckel equation from the molar conductivities and the limiting molar conductivities determined from the experiments. The activity coefficients increase with pressure and decrease with temperature and are almost constant at elevated temperatures and pressures.