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Noble antimony is the carrier of precious metals in the antimony smelting system and has a very high added value. This study proposes a novel, green, and effective vacuum gasification process for purifying antimony and recovering precious metals from noble antimony. Saturated vapor pressure and separation coefficients (β) were used to qualitatively analyze the possibility of separating elements from noble antimony, while vapor–liquid equilibrium (VLE) phase diagrams were used to quantitatively predict the degree of separation of alloying components and resulting product compositions. The effects of temperature and holding time on the antimony purity and the recovery efficiencies of Au and Ag were investigated by vacuum gasification experiments. The experimental results revealed that at an optimal temperature of 1123 K, the antimony purity in the volatiles was 99.41 pct. In the residues, the Au content was 11300 g/t and the recovery efficiency was 99.62 pct. Further, for Ag, these values were 2300 g/t and 66.56 pct, respectively. At an optimal holding time of 120 minutes, the antimony purity in the volatiles was 99.63 pct. In the residues, the Au content was 12100 g/t with a recovery efficiency of 99.75 pct, whereas the Ag content was 2600 g/t with a recovery efficiency of 67.12. Valuable metals in noble antimony are effectively purified and recovered via the vacuum gasification process without generating any waste gas and water. This work provides guidance for the separation of antimony and precious metals via the vacuum gasification of noble antimony, aligning with the principles of cleaner production. [ABSTRACT FROM AUTHOR]

The vapor-liquid equilibrium (VLE) phase diagrams of Pb-Pd and Pb-Pt alloy systems in vacuum distillation were obtained based only on pure-component properties and the structures of the atoms. The interaction energies between pairs of atoms were calculated from ab initio methods and were used as the input energy parameters for the Wilson equation. The calculated activity data of the components, using energy parameters which were obtained by ab initio methods, are in good agreement with the experimental data. It is revealed that a cluster size of eight atoms, optimized using the NVT ensemble at 300 K, a time step of 1 femtosecond, and the simulation time 10 ps gives a good representation of the liquid phase systems. This approach can be used to obtain accurate VLE predictions for alloy systems in vacuum distillation. The VLE phase diagram has a significant advantage in guiding experiment and industrial production in vacuum metallurgy. [ABSTRACT FROM AUTHOR]

In this paper, an innovative idea of vacuum separation and purification of crude silver is proposed, and theoretical calculations and kilogram-scale experimental studies are carried out. The theoretical calculation results show that the order of saturated vapor pressure and theoretical maximum volatilization rate of each element in crude silver is Se > Te > Sb > Bi > Pb > Ag > Cu > Au. In the temperature range of 1373–1773 K, the separation coefficient and vapor-liquid equilibrium composition of Ag-Au and Ag-Cu alloys were calculated. The experimental results show that the crude silver is mainly composed of Ag-Au and Ag-Cu-Se-Te phases. Under the optimal experimental conditions, the total volatilization rate of crude silver after primary vacuum separation and purification was 90.36%, and the distribution rates of gold and silver in the residue were 98.26% and 1.10%, respectively. The secondary vacuum separation and purification of the first and second order condenser volatile from the primary vacuum separation and purification were carried out, and gold was enriched 149 and 128 times in the residue, respectively, and the main phases of the volatiles were Ag, Ag 2 Se and Ag 2 Te, of residue were Au-Sb phase, Au-Cu phase and Au-Ag-Cu phase. • An innovative, green and efficient vacuum separation and purification of crude silver was developed. • A systematic theoretical study of the vacuum distillation was performed. • Experiments on separation and purification of crude silver by vacuum volatilization-stage condensation were carried out. • The occurrence state of each element in crude silver and experimental products were analyzed by EPMA. • The behavior of the precious metal platinum and palladium were investigated. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The activities of components of Sn-Zn system were predicted based on the molecular interaction volume model (MIVM). The separation coefficients and the vapor-liquid phase equilibrium of Sn-Zn system were also predicted using the MIVM. The predicted results indicated that the content of tin in the vapor phase was 0.000052 wt pct, while in the liquid phase, it was 99.98 wt pct at 1173 K (900 °C). Experimental investigations into the separation of Sn-Zn alloy by vacuum distillation were carried out for the proper interpretation of the predicted results. The effects of vacuum level (15 to 200 Pa), distillation temperatures [873 K to 1273 K (600 °C to 1000 °C)], and soaking time (20 to 60 minutes) were studied. The experimental results indicated that the content of tin in the vapor phase was 0.001 wt pct, while in the liquid phase, it was 99.98 wt pct at 1173 K (900 °C). The experimental results match well with the predicted data, suggesting that the MIVM is a suitable model for Sn-Zn system. [ABSTRACT FROM AUTHOR]

The activity coefficients of components of the Pb-Sn binary alloy system were calculated based on the molecular interaction volume model (MIVM). A significant advantage of this model lies in its ability to predict the thermodynamic properties of liquid alloys using only two binary infinite activity coefficients. Based on the MIVM, the vapor-liquid phase equilibrium of the Pb-Sn alloy system in vacuum distillation has been predicted using the activity coefficients of Pb and Sn. The results showed that the content of tin in the vapor phase was 0.008 wt pct, while in the liquid phase, it was 83 wt pct at 1173 K (900 °C); it reached 0.022 wt pct in the vapor phase, while in the liquid phase, it was 92 wt pct at 1223 K (950 °C); and it was 0.052 wt pct in the vapor phase, while in the liquid phase, it was 97.88 wt pct at 1273 K (1000 °C). The content of tin in the vapor phase increased with the distillation temperature increasing. Experimental investigations into the separation of Pb and Sn from the Pb-Sn alloy by vacuum distillation were carried out for the proper interpretation of the results of the model. The influence of the distillation time (20 to 80 minutes) and the distillation temperatures of 1173 K, 1223 K, and 1273 K (900 °C, 950 °C, and 1000 °C) on the separating effect was also studied. The experimental results showed that the content of tin in the vapor phase was 0.085 wt pct, while in liquid phase, it was 83 wt pct under the operational conditions of distillation temperature of 1173 K (900 °C), evaporation time of 20 minutes, and chamber pressure of 20 Pa; it reached 0.18 wt pct in the vapor phase, while in the liquid phase, it was 92 wt pct at 1223 K (950 °C), 20 minutes, and 20 Pa; and it was 0.35 wt pct in the vapor phase, while in the liquid phase, it was 97.88 wt pct at 1273 K (1000 °C), 20 minutes, and 20 Pa. In all these experiments, it was observed that the content of tin in the vapor phase increased as the distillation time and temperatures were increased. The experimental results are in good agreement with the predicted values of the MIVM for the Pb-Sn binary system. [ABSTRACT FROM AUTHOR]

Abstract: Phase equilibrium of Pb–Au and Pb–Sn systems in vacuum distillation have been predicted based on molecular interaction volume model (MIVM). A significant advantage of the model lies in its ability to predict the thermodynamic properties of liquid alloys using only binary infinite activity coefficients. The calculated activity coefficients are compared with experimental data showing good agreement with each other. This shows that the prediction effect of the proposed method is of better stability and reliability because the MIVM has a good physical basis. [Copyright &y& Elsevier]

Abstract The measurements of vapor-liquid equilibrium (VLE) for Cu-Bi and Cu-Bi-Sb alloys in vacuum distillation were performed. We calculated the VLE diagrams of Cu-Bi and Cu-Bi-Sb alloys at 10 Pa by Wilson equation only using binary parameters. Thermodynamic consistency tests of experimental data for the binary and ternary systems were discussed using the Van Ness method. The calculated results are in good agreement with the experimental data. The VLE data can be used for designing the purification process and phase separation of crude copper in vacuum metallurgy. Highlights • Separation of Bi and Sb from Cu in vacuum distillation is investigated. • The activities of components of Cu-Bi-Sb alloy are calculated by the Wilson equation. • VLE data for Cu-Bi and Cu-Bi-Sb systems in vacuum distillation are correlated using the Wilson equation. [ABSTRACT FROM AUTHOR]

In this study, an innovative method for vacuum gasification separation of Ag-Cu-Au alloy was proposed. The saturated vapor pressure of each component is calculated theoretically, and the activities of Au-Cu and Ag-Cu-Au alloys are calculated by molecular interaction volume model (MIVM). The results show that the activities of Au-Cu alloy calculated by MIVM is accurate and reliable. Based on activity prediction, the separation coefficients of Au-Cu alloy were calculated. The results show that the separation coefficients of Au-Cu alloy are between 0.0037 ∼ 0.6626 in the temperature range of 1337–1773 K. Subsequently, the vapor-liquid equilibrium composition and vapor-liquid equilibrium phase diagram of Au-Cu and Ag-Cu-Au alloys were calculated, and the vapor-liquid equilibrium measurement experiments of Ag-Cu-Au alloy were carried out. The results show that vacuum gasification is challenging to realize the separation of Au-Cu alloy. During the vacuum gasification separation process of Ag-Cu-Au alloy, silver volatilizes into the vapor phase. When the pressure is 10 Pa and the mole fractions of silver, copper and gold in the liquid phase are 0.2, 0.1 and 0.7, respectively, the equilibrium temperature is 1545.5 K, and the mole fractions of silver, copper and gold in the vapor phase are 0.994, 0.002 and 0.004 respectively. The corresponding experimentally determined mole fractions of silver, copper, and gold in the vapor phase were 0.9666, 0.0333, and 5.89 × 10−5, respectively. In addition, the distribution and occurrence state of each element in the vacuum separation process of Ag-Cu-Au alloy were determined by EPMA. [Display omitted] • An innovative separation method of Ag-Cu-Au alloy is proposed. • The activity of Ag-Cu-Au alloy was predicted using MIVM. • A systematic study of vacuum gasification separation theory was conducted. • The VLE measurement experiments of Ag-Cu-Au alloy were investigated. • The occurrence state and distribution behavior of elements were analyzed. [ABSTRACT FROM AUTHOR]

Vapor-liquid equilibria (VLE) and purification of tin from crude Sn containing Bi and Sb has been studied in vacuum distillation. The Sb-Sn and Bi-Sb-Sn systems were investigated in the temperature range from 1000 to 1500 K and at pressure of 5 Pa. Consequently, the content of Sn for the Bi-Sb-Sn system in the liquid phase reached more than 0.99 mol fraction as the temperature higher than 1500 K. It is shown that Bi and Sb can be satisfactorily removed from crude Sn. The VLE data of Sb-Sn and Bi-Sb-Sn alloys were calculated by using Wilson equation and compared with experimental values under vacuum condition. The capability of the equation to predicting the activities of components in whole composition range was also tested. It provides an efficient way to guide the process of vacuum distillation. The experiment results revealed that vacuum distillation is a promising method for the separation and purification of crude metals. [ABSTRACT FROM AUTHOR]

Vacuum distillation experiments were conducted for tin-antimony alloy (Sn–Sb alloy) under the system pressure of 5 Pa. The content of Sb (mole fraction) in crude Sn, viz., x Sb was reduced from 0.5000 to 0.0619 in a single stage distillation process under the condition of residual pressure of 5–10 Pa, distillation temperature of 1373 K and distillation time of 60 min. The activity coefficients of components of Sn–Sb alloy were calculated by using the molecular interaction volume model (MIVM), and the calculated average relative deviation and the average standard deviation were ±0.00039 and ± 0.173%, respectively for both Sn and Sb. The vapor–liquid equilibrium (VLE) phase diagrams, including the temperature-composition ( T - x ) and pressure-composition ( p - x ) diagrams of Sn–Sb alloy in vacuum distillation were calculated based on VLE theory and the MIVM. A reasonable agreement between the calculated results and the experimental data indicates that VLE phase diagrams obtained by this method are reliable. The VLE phase diagrams of alloys will provide an effective and convenient way for the designing of the process parameters of industrial production of vacuum metallurgy, and for the prediction of the needed product component dependence of temperature and pressure during the process of vacuum distillation. [ABSTRACT FROM AUTHOR]

• The ground state structure and stability of As n P m (m + n ≤ 8) clusters are analyzed. • The migration and distribution of elements during vacuum distillation and condensation were analyzed. • A new method for preparing high purity red phosphorus directly under vacuum condition was presented. • The removal rate of arsenic in industrial yellow phosphorus is greater than 99%. This study employs theories involving saturated vapor pressure, separation coefficient, and vapor–liquid equilibrium composition to investigate the feasibility of using vacuum distillation to separate phosphorus and arsenic. Ab initio molecular dynamics simulations are used to analyze the structure, stability, and dynamics of As n P m (m + n ≤ 8) clusters, assessing their impact on removing arsenic during the vacuum distillation of industrial yellow phosphorus. Theoretical calculations indicate that vacuum distillation is an effective method for removing arsenic from industrial yellow phosphorus. Throughout the vacuum distillation process, clusters like AsP, AsP 2 , AsP 3 , and others are prone to diffuse into the gas phase and remain stable, affecting the efficiency of arsenic removal. The collected red phosphorus shows a reduced arsenic content from 136 mg/kg to 1.09 mg/kg, confirming the feasibility of using vacuum distillation to eliminate arsenic from industrial yellow phosphorus and convert it into stable red phosphorus. [ABSTRACT FROM AUTHOR]

For the Bi–Zn and Bi–Sn–Zn systems, vacuum distillation experiments were carried out at 10 Pa. The results show that the content of Zn for the Bi–Zn system in the vapor phase could reach more than 0.999 mol fraction in vacuum distillation. The VLE (vapor-liquid equilibrium) data were correlated using the Tsuboka-Katayama's modification of the Wilson equation (T-K-Wilson). The correlation showed good agreement with experimental data. Thermodynamic consistency tests of experimental data for the binary and ternary systems were presented by the Van Ness method. The results demonstrate that VLE phase diagram is reliable for predicting the process of vacuum distillation for the systems. It provides an efficient way to guide the separation and purification of crude Zn in vacuum metallurgy • Vapor-liquid equilibria of Bi–Zn and Bi–Sn–Zn systems under vacuum condition were measured. • The T-K-Wilson equation was used to calculated activities of components. • The experimental data for the Bi–Zn and Bi–Sn–Zn systems were correlated using the T-K-Wilson equation. [ABSTRACT FROM AUTHOR]

Vacuum distillation of a zinc-silver (Zn–Ag) alloy under a system pressure of 5–10 Pa was conducted in the temperature range of 1173–1373 K. The Zn content in the Zn–Ag alloy was reduced from 70.80 wt% to 0.0026 wt% via a single-stage distillation process at a temperature >1373 K. The molecular interaction volume model (MIVM) was reasonably simplified. The activities of the Zn–Ag alloy components were calculated using the simplified molecular interaction volume model (SMIVM). The calculated average standard deviation for Zn and Ag were ±0.0078 and ±0.0082, and the average relative deviations were ±4.6758% and ±4.7564%, respectively. Simplicity and reliability are significant advantages of the SMIVM. The vapor-liquid equilibrium (VLE) phase diagram (T - x diagram) of the Zn–Ag alloy during vacuum distillation was calculated using the SMIVM and VLE theory. The results agree with the VLE data determined from experiments, which indicate that the resulting VLE phase diagram is reliable. The VLE phase diagram of alloys provides an intuitive and effective method for process optimization, development, and prediction of the dependence of product composition on system pressure and temperature during vacuum distillation. • The VLE data and phase diagram of Zn–Ag alloy were reported for the first time. • The molecular interaction volume model (MIVM) was reasonably simplified. • Ag and Zn with high purity can be obtained by vacuum distillation technology. • A reliable and effective method for calculation of VLE was provided. • The distribution of the components of Zn-based alloys can be quantitatively predicted. [ABSTRACT FROM AUTHOR]

• A novel method for the sustainable separation and purification recovery of In-Sn, In-Zn and In-Sn-Zn alloys was proposed. • The optimal experimental conditions for the separation of In-based alloys were determined. • The VLE data of the In-Sn, In-Zn and In-Sn-Zn systems were experimentally determined for the first time. • The predicted VLE values were in agreement with the experimental data. • A reliable thermodynamic model for VLE prediction was provided. The vacuum distillation (VD) method was studied for extraction of valuable metals from In–Zn, In–Sn, and In–Sn–Zn waste alloys. The VD studies were carried out between 773 K and 1073 K, at 5 Pa, and for 60 min for the In–Zn alloys. The In content in the residues was greater than 99.999 wt%, and the Zn content in the volatiles was the highest at 99.8962 wt%. For the In-Sn alloys, the VD experiments were carried out from 1323 K to 1573 K at 5 Pa for 540 min for the In–Sn alloys. The Sn content in the residues exceeded 99.9963 wt%, whereas the In content in the volatiles was 99.86 wt%. Further, the In–Sn–Zn VD was carried out between 773 K and 1073 K at 5 Pa for 90 min. The Zn content of the residues decreased from 6.0 wt% to 0.0009 wt%, while the Zn content of the volatiles was 99.79 wt%. Using the M-MIVM and vapor–liquid equilibrium (VLE) theories, the VLE data was predicted and the related phase diagrams for the binary and ternary alloys were displayed. The remarkable similarity between theoretical and experimental VLE phase diagrams demonstrates the reliability of the M-MIVM for In-based alloys. [ABSTRACT FROM AUTHOR]

Copper is capable of maintaining strong competitiveness in the metal materials market for its prominent ductility, thermal conductivity, and electrical conductivity. As more rigorous purity requirements of industrial sputtering targets and aerospace have been raised, the clean and efficient production of high-purity copper turns out to be an urgent problem over the past few years. In this paper, the possibility of removing impurities from copper melt was investigated by integrating theoretical calculations and experiments, and the separation coefficient and vapor-liquid equilibrium phase diagram of copper and impurity elements were determined and plotted using the molecular interaction volume model (MIVM). Moreover, the effects of the distillation temperature, the holding time, and the system pressure on the experimental results were discussed. As indicated by the results, with the rise of the temperature and with the extension of the holding time, the purity of copper was first increased and then decreased, and the purity of residual copper reached 99.9993% at 1473 K temperature, 1.5 h holding time, and 5 Pa pressure, and the method effectively separated impurities from copper raw materials. Besides, no waste water or waste gas emission was generated in the experiment. • Vacuum distillation technology used in this paper does not involve chemical reactions, and uses pure physical methods to separate impurities, which shortens the preparation process. • Compared with electrolysis, and the preparation of high-purity copper by vacuum distillation achieves almost zero emissions, the energy consumption is less. [ABSTRACT FROM AUTHOR]

In this study, a novel method was proposed for the clean and efficient recovery of high-value-added In–Sn and In–Sn–Bi alloys. Vacuum volatilization of the In–Sn binary alloy was conducted in a temperature range of 1373–1573 K with a system pressure of 5 Pa. The results showed that In and Sn were effectively separated. The Sn content in the residue was 99.9908%, and the In content in the volatile fraction reached 99.66%. Vacuum volatilization of the In–Sn–Bi ternary alloy was conducted out at 1073–1373 K and 5 Pa. The results showed that Bi could be separated from In and Sn, the Bi content in the residue decreased from 32.5% to 3.88%, and the Bi content in the volatile fraction reached 95.67%. The residual In–Sn alloy could be effectively separated by vacuum volatilization. The MIVM, M-MIVM, Wilson equation and NRTL were used to calculate and analyze the activity and activity coefficients of In–Sn, In–Bi, Sn–Bi and In–Sn–Bi alloy elements, respectively, and the results showed that M-MIVM had the highest prediction accuracy. The vapor-liquid equilibrium (VLE) data of the In–Sn, In–Bi, Sn–Bi, and In–Sn–Bi alloys were predicted, and the corresponding VLE phase diagrams were plotted based on the M-MIVM and VLE theory. The predicted VLE values were in good agreement with the corresponding experimental data determined in this study, indicating that the M-MIVM was reliable for indium-based alloys. The results of this work provided reliable experimental data and a thermodynamic model for the VLE study of In-based alloys, opening a new technique for the clean and efficient recycling of binary and multicomponent In-based alloys. • A novel method for the clean and efficient recovery of In–Sn and In–Sn–Bi alloys was proposed. • The optimal experimental conditions for the separation of In–Sn and In–Sn–Bi alloys were determined. • The VLE data of the In–Sn and In–Sn–Bi systems were experimentally determined for the first time. • The predicted VLE values were in agreement with the experimental data. • A reliable thermodynamic model for VLE prediction was provided. [ABSTRACT FROM AUTHOR]

This study reports the measurement and modeling of vapor-liquid equilibrium (VLE) in In–Pb and In–Pb–Sn alloys subjected to vacuum distillation at a system pressure of 5–10 Pa in the temperature range of 1100–1280 K. Pb and In was satisfactorily separated by a single-stage distillation at 1180 K. Pb was thoroughly removed from In–Pb–Sn alloy by a single-stage distillation at 1220 K. Molecular interaction volume model (MIVM) was used to calculate the activities of components of In–Pb alloy. The deviations were small. The activities of components of In–Pb–Sn alloy were also predicted by MIVM. The VLE of In–Pb and In–Pb–Sn alloy systems were predicted by MIVM and VLE theory. The calculated results agree well with VLE data determined from experiments, which indicates that the calculated VLE is reliable. The VLE can be used to guide the separation of indium-based alloys by vacuum distillation. In this study, the model prediction was combined with vacuum distillation experiments, which not only verified the reliability of MIVM for indium-based alloys, but also optimized the process parameters of vacuum distillation of indium-based alloys, providing theoretical guidance for the separation and purification of indium-based alloys by vacuum distillation or the treatment of indium-containing complex materials. • In–Pb alloy was satisfactorily separated by a single-stage vacuum distillation. • Pb was thoroughly removed from In–Pb–Sn alloy by a single-stage vacuum distillation. • The VLE phase diagram of In-based alloy systems was calculated using the MIVM. • The VLE data of In-based alloy systems were experimentally determined for the first time. • The calculated results are in agreement with the experimental VLE data. [ABSTRACT FROM AUTHOR]

In this work, interaction energies between pairs of atoms for the Ag–Pb, Cu–Pb and Sn–Pb systems have been calculated using ab initio methods. These energies are then used as the interaction energy parameters in the Wilson equation. Phase diagram of vapor–liquid equilibria (VLE) for the Pb-based alloy systems in vacuum distillation are obtained based on the calculated parameters. The results indicate that this approach can lead to accurate VLE predictions for alloy systems in vacuum distillation based only on properties of pure components and the structure of the clusters. The comparisons show the computational results are in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

In this work, vapor–liquid equilibria (VLE) of the Ag–Cu–Pb system were experimentally investigated in vacuum distillation. The experimental results show that the content of Pb in liquid phase is 0.005 (mole fraction) under the experimental condition of 1173 K, 90 min and 10 Pa. The amount of Pb in volatiles increased to 0.9911 (mole fraction). It indicates that Pb can be satisfactorily removed from Ag–Cu alloy. With the Wilson equation, the partial Gibbs free energies of Pb in liquid Ag–Cu–Pb alloys were calculated, and the predicted values agree well with the experimental data, which shown that the interaction parameters are reliable. Using binary data only, the VLE for the Ag–Pb and Ag–Cu–Pb systems under vacuum condition were obtained. The calculation results demonstrate that this approach can lead to accurate VLE data predictions for the binary and ternary systems based on the Wilson equation. [ABSTRACT FROM AUTHOR]

In this study, vacuum distillation experiments of high-lead crude copper were performed under the vapor pressure 5 Pa. The content of lead in crude copper was reduced from 15% to less than 0.01% in a single stage distillation process with residual vapor pressures of below 10 Pa, distillation temperatures of 1423 K and distillation times of 60 min. The vapor–liquid equilibrium (VLE) phase diagrams of Cu–Pb binary alloy in vacuum distillation were calculated using the Wilson equation. Thermodynamic experimental data taken from literature were used for calculating Wilson equation temperature dependent interaction parameters. The calculations give a satisfactory accuracy with the experimental data for separation of Cu–Pb alloy in vacuum distillation. The results indicate that VLE phase diagrams under vacuum obtained by this method are reliable for predicting the process of vacuum distillation for Cu–Pb alloy. The VLE phase diagrams of alloys will have significant benefits for the industrial production of vacuum metallurgy especially for the process of multistage distillation in the vacuum furnace. [ABSTRACT FROM AUTHOR]

In this paper, the modified molecular interaction volume model (M-MIVM) was used to calculate the activities of components of the PbS–Sb 2 S 3 binary matte system. On this basis, the vapor-liquid equilibrium (VLE) data of the PbS–Sb 2 S 3 system were calculated by M-MIVM in combination with the theory of vacuum metallurgy and VLE. Additionally, the VLE experiment of the PbS–Sb 2 S 3 binary matte system was conducted to correctly interpret the results of the model. The calculated results of the VLE of the model were consistent with the experimental values, and the VLE calculation of the PbS–Sb 2 S 3 binary matte system by M-MIVM was reliable. This is an effective and convenient method to predict the relationship between product components with temperature and pressure in vacuum distillation of PbS and Sb 2 S 3 mixed melts, providing theoretical guidance for vacuum separation and purification of PbS and Sb 2 S 3. • Vapor-liquid equilibrium experiment of PbS–Sb 2 S 3 was studied under vacuum firstly. • M-MIVM model was first to predict the activities of the PbS–Sb 2 S 3 system. • The predicted result of M-MIVM model is consistent with the experimental result. • Providing reference on the application of M-MIVM model in the sulfide minerals. [ABSTRACT FROM AUTHOR]

A procedure has been proposed to calculate the vapor–liquid equilibrium (VLE) phase diagrams of Pb–Sn and Pb–Ag alloys in vacuum distillation based on VLE calculations and molecular interaction volume model (MIVM). The results show good agreement with experimental data which indicate that VLE phase diagram under vacuum obtained by this method is available and reliable. The VLE phase diagram provides an intuitive and convenient way to analyze the product component dependence of temperature or pressure during the process of vacuum distillation. It has a significant advantage to guide for the experiment and industrial production in vacuum metallurgy. [ABSTRACT FROM AUTHOR]

Vapor-liquid equilibria (VLE) of the Cu–Sn system have been investigated in the temperature range from 1612 to 1650 K and at pressure of 5 Pa. The VLE data of Cu–Sn alloy was calculated by using Wilson equation and compared with experimental values under vacuum condition. The thermodynamic consistency of the experimental data was checked by Van Ness method. The azeotropic and non-azeotropic regions are plotted by correlating the Wilson equation, vapor pressure equation and the enthalpies of vaporization. The calculated results reveal that the Cu–Sn system is located in azeotropic region which the specific composition and temperature of azeotropic point are x C u = 0.71 and T = 1649 K. The agreements between calculated and measured results are good. This work provides an effectively method for predicting whether binary system will form an azeotrope or not and the azeoropic position in vacuum distillation. It can also be used to test the quality of a vapor-liquid equilibrium model and to guide experiments. • The experimental data of VLE in vacuum distillation are correlated using Wilson equation for the Cu–Sn system. • The positions of azeotrope of Cu–Sn system in vacuum distillation are predicted. • It is successful to predict whether the Cu–Sn system forms an azeotrope or not under vacuum distillation. [ABSTRACT FROM AUTHOR]