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A novel recycling process was developed to produce vanadium aluminum (AlV55) alloy using vanadium aluminum (AlV65) alloy scrap and aluminum (Al) under vacuum. The theoretical calculation indicates that Al can be evaporated under vacuum. Excessive Al would be consumed during melting process when the reaction temperature ranges from 1823 to 2123 K, according to the theoretical calculation, which indicates...
The hot deformation behavior and microstructural evolution of SA508-ІV steel for a novel nuclear reactor pressure vessels were studied by hot compression tests in the strain rates 0.001–1 s−1 and temperature ranges 950–1250 °C respectively. The results showed that the high temperature (1250 °C) and low strain rate (0.001 s−1) were more likely to induce the abnormal growth of grains, resulting in the...
The decomposition of solid Al2O3 in the presence of C was researched at 1873 K–2073 K in vacuum, using α-Al2O3 powders as the raw materials and the graphite crucible as C source. There was no direct contact between the Al2O3 and the C. The results showed that the Al2O3 decomposed into gaseous species, and the C making up the graphite crucible was reacted to form CO. The coupled reaction was proposed:...
In this work, the kinetics of Pb evaporating from Pb-Sn alloy has been investigated. The experiments were performed in the temperature range 1200 K–1400 K and the pressure of 10 Pa. The results indicated that the evaporation of Pb follow first order kinetics. The overall mass transfer coefficients of lead evaporation from Pb-Sn alloy are 2.68 × 10−6 m s−1, 5.01 × 10−6 m s−1 and 1.92 × 10−5 m s−1 at...
The vapor-liquid equilibria (VLE) for SnBi binary alloy at 5 Pa were carried out at distillation temperatures in the range of 1150 K–1550 K under vacuum condition. The experimental results indicate that Bi can be satisfactorily removed from crude Sn, the content of tin in liquid phase reaching more than 99.99 wt% at a temperature higher than 1300 K. The thermodynamic consistency of the experimental...
Ab-initio molecular dynamics simulations are performed to study the structural and electronic properties of liquid Pb–Sb alloys at eight concentrations. This alloy is known as azeotropic compounds within a certain ingredients at different temperature. The separation of Pb–Sb alloys is experimental carried out by vacuum distillation at 1173 K. Our predictions are coincident with the available experimental...
The formula for jamesonite is Pb4FeSb6S14 (or 4PbS·FeS·3Sb2S3). This paper proposes a novel method for the separation and enrichment of PbS and Sb2S3 from jamesonite by vacuum distillation. The experiments were carried out at temperatures ranging from 1073 K to 1473 K and at pressures less than 10,000 Pa. The amount of Sb, Pb, and Fe in the volatiles and residues was determined by chemical titration...
AlN chlorination route, in the present work, was proposed to extract Aluminum from aluminum nitride under vacuum. Density functional theory (DFT) were implemented to study the interaction of AlCl 3 molecule and AlN (101¯0) surface. The results of DFT indicate that chemisorbed AlCl 3 adsorption configuration was observed on the clean AlN (101¯0) surface after structure optimization,...
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...
The vacuum volatilization of aluminum from silicon melt is studied by the molecular interaction volume model (MIVM) in this paper. The activities and activity coefficients of components in the Si–Al binary melt were investigated based on the MIVM and the results show that the predicted values of activities are in good agreement with the experimental data. The infinite dilution activity coefficients...
Pre-oxidation vacuum decarburization process was employed to decarburize high carbon ferromanganese. In pre-oxidation stage, the degree of oxidation was controlled by changing roasting time and 13.17% carbon was removed. In the vacuum decarburization stage, C in ferromanganese and O captured in pre-oxidation stage further reacted to decarburize ferromanganese by increasing reaction temperature and...
The chlorination-disproportionation of Al 4 O 4 C and Al 4 C 3 in vacuum was investigated by thermodynamic analysis and experiments using the side products of the AlCl disproportionation process of alumina, consisting of Al 4 O 4 C, Al 4 C 3 , Al 2 O 3 and C, as raw materials. It was demonstrated that the chlorinations...
Based on the molecular interaction volume model (MIVM), the vapor–liquid phase equilibrium of Sn–Sb alloy was calculated, which was used to predict the element distribution of Sn–Sb alloy between vapor and liquid phase during vacuum distillation. A central composite design (CCD) was used to optimize the process parameters influencing the content of Sn in liquid phase and the direct yield of Sn. The...
A novel technology was developed to remove impurities from crude lead with high impurities by vacuum distillation. Refined lead (purity over 99%) was achieved through vacuum distillation using crude lead (92.88%) with high impurities as input material under a dynamic vacuum of 5–15 Pa. The results show that vacuum distillation should be taken to obtain lead from crude lead matrix, in which low-volatile...
In this paper, the molecular interaction volume model (MIVM) has been used for a calculation of the activities of components of Pb–Sn–Sb ternary alloy system. The separation coefficients of the related binary alloys Sn–Pb and Sn–Sb and the vapor–liquid phase equilibrium of the Pb–Sn–Sb alloy system were also calculated by using the MIVM. Experiments for the separation of the Pb–Sn–Sb ternary alloy...
Characteristics and synthesis mechanism of Gd 2 O 2 S:Tb phosphors prepared by vacuum firing were investigated by photoluminescence (PL) spectra, X-ray diffraction (XRD), scanning electronic microscopy (SEM) and transmission electron microscopy (TEM). The mixtures of raw materials were tested by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The firing...
In this research, thermodynamic analysis and XRD were used to study the products in carbothermal reduction of Al 2 O 3 under vacuum. Gaseous reduction product, Al(g) or Al 2 O(g), was produced in carbothermal reduction of Al 2 O 3 at 1623 K under 5–30 Pa, and carried out further reactions with CO(g) to produce Al 4 O 4 C, Al 4 C 3...
A method is presented for calculating the separation coefficients of Pb–Au and Pb–Sn alloys in vacuum distillation 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 results of Pb–Ag, Pb–Au, Pb–Sb, Pb–Sn and Sb–Sn show good...
The chlorination process in aluminum production by carbothermic-chlorination reduction of Al 2 O 3 under vacuum has been investigated by XRD, SEM and thermodynamic analysis. The results of thermodynamic calculations indicated that the chlorination of Al 4 C 3 or Al 4 O 4 C possibly proceeded at temperature 1300 °C under 5–50 Pa. The experiment results...
In this study the transmission probability for Knudsen diffusion through a single chamber-throat pore is simulated by the test-particle Monte Carlo method. The effects of the ratios of the length to the throat radius and the chamber radius to the throat radius on transport properties are investigated. The mechanisms affecting the transmission probability are revealed and discussed in detail. It is...
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