改进的MIVM在Cd-Cu-Zn合金的活度计算和气液平衡研究

Study on Activity Calculation and Vapor-Liquid Equilibrium of Modified MIVM in Cd-Cu-Zn Alloy

在湿法炼锌的冶炼过程中,通过锌粉置换硫酸锌溶液中的铜和镉,采用真空蒸馏技术综合回收利用高镉渣是一项重要的工艺。本文采用改进的分子相互作用体积模型(M-MIVM)对Cd-Cu-Zn合金的活度进行了预测,并以此为基础,预测了Cd-Cu-Zn合金在真空蒸馏过程中的气液平衡。结果表明,在二元合金中的活度实验值与模型计算值比较中,M-MIVM的总平均标准偏差0.0037,相较于传统的局部组成模型有更好的精确度和稳定性。本文研究可为高纯镉的生产以及粗镉的综合回收利用提供较为准确的基础热力学数据;同时,也为预测真空蒸馏的气液相平衡计算提供理论基础。

In the process of hydrometallurgy of zinc,copper and cadmium in the solution of zinc sulfate are replaced by zinc powder,and vacuum distillation is an important process for comprehensive recovery and utilization of high cadmium slag.In this paper,the modified molecular interaction volume model(M-MIVM)is used to predict the activity of Cd-Cu-Zn alloy,and on this basis,the vapor-liquid equilib-rium of Cd-Cu-Zn alloy during vacuum distillation is predicted.The results show that the total average standard deviation of M-MIVM is 0.0037 in the comparison between the experimental value of activity in the binary alloy and the calculated value of the model,which has better accuracy and stability than the traditional local composition model.This study can provide more accurate basic thermodynamic data for the production of high-purity cadmium and the comprehensive recovery and utilization of crude cadmium;at the same time,it also provides a theoretical basis for predicting the vapor-liquid equilibrium calculation of vacuum distillation.