(1. 昆明理工大学 真空冶金国家工程实验室，昆明 650093；
2. 昆明理工大学 云南省有色金属真空冶金重点实验室，昆明 650093；
3. 昆明理工大学 复杂有色金属资源清洁利用国家重点实验室，昆明 650093；
4. 昆明理工大学 冶金与能源工程学院，昆明 650093)
摘 要: 采用正规溶液模型、亚正规溶液模型以及简化的分子相互作用体积模型(Simplified molecular interaction volume model, SMIVM)预测Pb-Sn、Sb-Sn、Bi-Sn合金组元的活度，并计算模型的预测偏差。结果表明：SMIVM的平均标准偏差最小，分别为0.0050和0.0046，表明采用SMIVM预测锡基合金组元的活度是可靠的。在此基础上，采用SMIVM，结合真空冶金及气液平衡理论，建立二元合金体系的气-液平衡(Vapor-liquid equilibrium, VLE)预测模型。采用该模型计算上述锡基合金的VLE数据，并绘制VLE相图(包括T-x(y)和p-x(y)相图)，最后采用VLE实验数据检验其可靠性。结果表明：采用该方法预测锡基合金体系的气-液相平衡具有较高的可靠性。依据气-液平衡相图，分析真空蒸馏分离锡基合金的实验条件以及不同蒸馏条件下的产物成分，可为真空蒸馏设备的改进及蒸馏过程优化提供理论依据。
关键字: 真空蒸馏；锡基合金；活度；气-液相平衡；热力学模型
（1. National Engineering Laboratory for Vacuum Metallurgy, Kunming University of Science and Technology, Kunming 650093, China;
2. Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province, Kunming University of Science and Technology, Kunming 650093, China;
3. State Key Laboratory Breeding Base of Complex Nonferrous Metal Resources Clean Utilization in Yunnan Province, Kunming University of Science and Technology, Kunming 650093, China;
4. Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China）
Abstract:The activities of components of Pb-Sn, Sb-Sn, Bi-Sn alloys were predicted using the regular solution model(RSM), the sub-regular solution model (SRSM) and the simplified molecular interaction volume model (SMIVM). The average standard deviation of the MIVM is the smallest, which is 0.0050 and 0.0046, respectively, indicating that the simplified MIVM is reliable for the prediction of the activities of components of Sn-based alloys. The vapor-liquid equilibrium (VLE) prediction model for binary alloy systems is developed by using the MIVM combined with vacuum metallurgy and VLE theory. The VLE data of the above Sn-based alloys was calculated, and the VLE phase diagrams (including T-x(y) and p-x(y) phase diagram) were drawn by using the calculated VLE data. A comparison between the calculated VLE data and experimental data was also carried out for validation purpose, which indicates that the method is reliable for prediction of VLE of Sn-based alloy systems. The experimental conditions for separating Sn-based alloys by vacuum distillation and the composition of product under different distillation conditions were analyzed based on the VLE phase diagrams, which can provide theoretical basis for the improvement of vacuum distillation equipment and the optimization of distillation process.
Key words: vacuum distillation; tin-based alloy; activity; VLE; thermodynamic model
