1090K下MgCl_2-KCl-CaCl_2三元熔盐体系的密度预测

Prediction of the density of molten MgCl_2-KCl-CaCl_2 ternary at 1090 K

镁电解工艺中使用的电解质需要具有合适的密度范围.MgCl2-KCl-CaCl2三元熔盐体系是镁电解质的重要基础三元系.使用了新一代溶液几何模型,预测了这一三元系在1 090 K下的密度.首先勘正了标准数据库中的MgCl2-CaCl2熔盐二元系的密度表达式.对已知3个二元系KCl-CaCl2、MgCl2-CaCl2、KCl-MgCl2数据,采用三次式表达的Redlich-Kister关系式拟合得到了它们的超额密度函数.并计算各组分之间的相似系数.最终获得全组分范围内的三元熔盐体系密度分布图.已知成分点的实验值与预测值之间相对误差在2.21%～0.99%之间,这表明了预测结果的可靠性.

Electrolyte used for magnesium production should be maintained in a proper range of densities.MgCl2-KCl-CaCl2 ternary is one of the important basal melts of the electrolyte. The new generational geometric model is employed to predict the density of the ternary at the temperature of 1 090 K. Before the prediction,the density functions of molten MgCl2-CaCl2 binary to temperature are revised based on the data of NSRDS.The excess density functions of KCl-CaCl2,MgCl2-CaCl2,KCl-MgCl2 are fitted with Redlich-Kister equation.And the similarity coefficients of the three components in the ternary are worked out. The calculation results of the model are compared with the known experimental data. The relative errors of the predicted data are in the range of 2.21 %～0.99 %. Therefore, it is proposed that the prediction results are reliable.