真空蒸馏Zn-Ni二元合金气−液相平衡研究

Research on vapor-liquid equilibrium of Zn-Ni binary alloy in vacuum distillation

在系统压力5~10 Pa、蒸馏温度1173~1423 K条件下,开展Zn-Ni二元合金真空蒸馏实验研究。结果表明:液相中Ni含量(质量分数)由18.21%增至96.05%时,气相中的Zn含量由0增至99.9966%,并且通过实验获得真空蒸馏中Zn-Ni二元合金的气−液平衡(Vapor-liquid equilibrium,VLE)实验数据。采用Wilson方程预测了Zn-Ni二元合金组元的活度,且平均绝对偏差分别为0.0062和0.0112,平均相对偏差分别为5.8170%和4.8179%。另外,基于VLE理论,采用Wilson方程计算了Zn-Ni合金的VLE数据,绘制VLE相图,并与实验值进行了比较。结果表明:计算值与实验值相吻合,表明采用Wilson方程预测Zn基合金的VLE数据是可靠的。本研究结果不仅验证了Wilson方程在预测VLE数据用于指导真空蒸馏分离合金的可行性,同时也丰富了锌基合金的热力学数据,可为有色金属真空分离实践提供可靠的理论依据和指导。

Under the conditions of system pressure of 5−10 Pa and temperature of 1173−1423 K,the vacuum distillation experiments of zinc-nickel(Zn-Ni)binary alloy were carried out.The results show that the Ni content(mass fraction)in the liquid phase increases from 18.21%to 96.05%at 1423 K and the Zn content in the vapor phase increases from 0 to 99.9966%.The experimental data of the vapor-liquid equilibrium(VLE)of the Zn-Ni binary alloy in vacuum distillation were obtained through experiments.The Wilson equation is used to predict the activity of the components of Zn-Ni binary alloy,the average absolute deviations are 0.0062 and 0.0112,respectively,and the average relative deviations are 5.8170%and 4.8179%,respectively.Based on VLE theory,the VLE data of Zn-Ni alloy were calculated using Wilson equation,and VLE phase diagram was drawn.The comparison between calculated values and experimental VLE data shows that the calculated values are in good agreement with the experimental data,which indicates that the prediction of VLE data of Zn-based alloys by Wilson equation is reliable.The results of this study not only verify the feasibility of the Wilson equation thermodynamic model in predicting the use of VLE data to guide the vacuum distillation separation of alloys,but also enrich the thermodynamic data of zinc-based alloys and provide a reliable theoretical basis and guidance for the practice of vacuum separation of non-ferrous metals.