Yifu Li

Application of Molecular Interaction Volume Model for Phase Equilibrium of Sn-Based Binary System in Vacuum Distillation

Based on the molecular interaction volume model (MIVM), the activities of components of Sn-Sb, Sb-Bi, Sn-Zn, Sn-Cu, and Sn-Ag alloys were predicted. The predicted values are in good agreement with the experimental data, which indicate that the MIVM is of better stability and reliability due to its good physical basis. A significant advantage of the MIVM lies in its ability to predict the thermodynamic properties of liquid alloys using only two parameters. The phase equilibria of Sn-Sb and Sn-Bi alloys were calculated based on the properties of pure components and the activity coefficients, which indicates that Sn-Sb and Sn-Bi alloys can be separated thoroughly by vacuum distillation. This study extends previous investigations and provides an effective and convenient model on which to base refining simulations for Sn-based alloys.

Application of MIVM for Sn-Ag and Sn-In Alloys in Vacuum Distillation

In this study, the vapor-liquid phase equilibrium compositions of tin-silver (Sn-Ag) and tin-indium (Sn-In) alloys in vacuum distillation were predicted based on the molecular interaction volume model (MIVM) and vacuum distillation theory, which can be used to precisely estimate the separation degree and the product composition in vacuum distillation. The calculated values of activities of components in Sn-Ag and Sn-In alloys are in good agreement with experimental data, which indicates that the method is reliable and convenient due to the MIVM has a clear physical basis and can predict the thermodynamic properties of multi-component liquid alloys using only two infinite dilute activity coefficients. This study provides an effective and convenient model on which to base refining simulations for Sn-based alloys.

Thermodynamic Analysis and Experiments on Vacuum Separation of Sn‐Sb Alloy

In this study, the saturated vapor pressures of tin (Sn) and antimony (Sb), the separation coefficient s and the vapor-liquid phase equilibrium of Sn-Sb alloy were theoretically analyzed, which demonstrate that it is possible to separate Sn and Sb by vacuum distillation. The process parameters of vacuum distillation, including the distillation temperature, distillation time and alloy mass (thickness of raw materials) on the direct yield of Sn and the content of Sn in liquid phase were investigated by using single factor experiments. The preliminary results show that the direct yield and the content of Sn are 98.77 wt.% and 96.01% with the optimized distillation conditions of a distillation temperature of 1473 K, a distillation time for 45 min and a Sn-Sb alloy mass of 125 g (thickness of 8mm). The distillation parameters in the study provide effective and convenient conditions on separation of Sn-Sb alloy.

(Vapor + Liquid) Equilibrium (VLE) for Binary Lead-Antimony System in Vacuum Distillation: New Data and Modeling Using Nonrandom Two-Liquid (NRTL) Model

In this work, new experimental vapor–liquid equilibrium (VLE) data of lead-antimony alloy (Pb-Sb alloy) in vacuum distillation are reported. The activity coefficients of components of Pb-Sb alloy were calculated by using the NRTL model. The calculated average relative deviations were ±0.1425 and ±0.2433 pct, and the average standard deviations were ±0.0009 and ±0.0007, respectively, for Pb and Sb. The VLE phase diagrams, such as the temperature composition (T-x) and pressure composition (P-x) diagrams of Pb-Sb alloy in vacuum distillation were predicted based on the NRTL model and VLE theory. The predicted results are consistent with the new experimental data indicating that VLE phase diagrams obtained by this method are reliable. The VLE phase diagrams of alloys will provide an effective and intuitive way for the technical design and realization of recycling and separation processes. The VLE data may be used in separation processes design, and the thermodynamic properties as the key parameters in specific applications.

Application of MIVM for Cu-Ni Alloy in Vacuum Distillation

The activities of components in Cu-Ni alloy were predicted based on the molecular interaction volume model (MIVM). The required binary parameters B ij and B ji were determined by using the Newton—Raphson methodology with the aid of the experimental data of infinite dilution activity coefficients γi∞, γj∞. The predicted values of the activities match well with the experimental data, which show that the predicting effect of this method is reliable due to the MIVM has a good and clear physical basis. The separation coefficients of Cu-Ni alloy were far larger than 1. The vapor-liquid phase equilibrium of Cu-Ni alloy was also predicted by using the activity coefficients, which indicates that Cu and Ni can be concentrated in vapor phase and liquid phase respectively by vacuum distillation. This study extends previous investigations and provides an effective and convenient model on which to base separation simulations for Cu-Ni alloy by vacuum distillation.