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Shi S.,Kunming University of Science and Technology | Shi S.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | Yang B.,Kunming University of Science and Technology | Yang B.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province
Fenmo Yejin Jishu/Powder Metallurgy Technology | Year: 2011

The flake copper powder was prepared by the evaporation and condensation in vacuum, and characterized by laser particle size analyzer (SL), scanning electron microscopy (SEM), glow discharge mass spectrometry (GDMS) and X-ray diffraction (XRD). The results reveal that the copper powders are of face-center-cubic structure, with even surface and uniform shape, and dispersed well. The average particle size is 10~30 μm, the thickness of the flake copper powder is about 1~2 μm. The influence of evaporating temperature, vacuum degree, holding time and condensation distance on particle size and morphology was investigated. Results show that evaporating rate is effected by evaporating temperature and vacuum degree. The formation mechanism of Cu particles was discussed. Source


Lu Y.,Kunming University of Science and Technology | Lu Y.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | Zhou Y.,Kunming University of Science and Technology | Zhou Y.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | And 13 more authors.
Vacuum | Year: 2015

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 AlCl3 molecule and AlN (101¯0) surface. The results of DFT indicate that chemisorbed AlCl3 adsorption configuration was observed on the clean AlN (101¯0) surface after structure optimization, and adsorbed AlCl molecules were generated after 1 ps dynamic simulation time. The phase and composition of condensate were examined by means of XRD and EDS. It was found that 97.76 wt% of Al metal was obtained in the experiment B (in the presence of AlCl3), however, no condensate was collected in the experiment A (without AlCl3) at 1760 K under pressure of average 60 Pa. The results show that AlN chlorination route is an alternative Al production method from aluminum nitride. © 2015 Elsevier Ltd. All rights reserved. Source


Li Y.,Kunming University of Science and Technology | Li Y.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | Wang A.,Kunming University of Science and Technology | Wang A.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | And 6 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2015

A novel environmental friendly technique was developed to remove the As and Sb impurities from the crude tin (with Cu and Fe removed in advance) on industrial scale by a combination of vacuum distillation and multi-stage condensation. The impact of the distillation conditions, including but not limited to the distillation temperature and time, pressure, daily-processing capacity, and multi-stage condensation, on the removal rates of As and Sb and extraction rate of Sn were theoretically analyzed and experimentally evaluated. The preliminary results show that the new technique is capable of refining the crude tin by removing most of As and Sb impurities. For instance, under the conditions: a temperature in 1200~1400℃ range, a pressure in 10~30 Pa range and with a daily-processing capacity of 18~20 t/d, the purity of the distilled Sn was 99.575% (wt), because over 70% of the As and Sb impurities were removed and turned into metallic As and Sn-Pb-Sb alloy. ©, 2015, Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology. All right reserved. Source


Li Y.,Kunming University of Science and Technology | Li Y.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | Liu D.,Kunming University of Science and Technology | Liu D.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | And 7 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2014

The feasibility of extraction of Sn from ternary Sn-Pb-Sb alloy by vacuum distillation, a novel environmental friendly technique, was theoretically analyzedand experimentally studied. The impacts of the vacuum distillation conditions, including the distillation temperature and time, pressure, and alloy mass and contents, on direct recovery rate of tin from ternary alloy (Sb 26.07%) were investigated in orthogonal experimental design. The contents in slag were characterized. The preliminary results show that three factors significantly affect the separation rate of Sn, and their impacts are listed in a descending order: distillation temperature, distillation time, and alloy mass. The optimized distillation conditions inclue a distillation temperature of 1200°C, a distillation time for 25 min. and a Sn-Pb-Sb alloy thickness of 6.6 mm. Source


Zhou Y.,Kunming University of Science and Technology | Zhou Y.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | Lu Y.,Kunming University of Science and Technology | Lu Y.,Key Laboratory of Vacuum Metallurgy of Non Ferrous Metals of Yunnan Province | And 10 more authors.
Vacuum | Year: 2015

Vacuum decomposition process of molybdenite concentrate was investigated under pressure of 5-35 Pa for 15-120 min at the temperature range 1473 K-1973 K. The theoretical and experimental results showed that Gibbs free energy of vacuum decomposition reactions and evaporation rate of pure sulfur provided the theoretical calculation basis for temperature and heat preservation time selection in vacuum decomposition experiments of molybdenite concentrate. Melting points and saturated vapor pressures of pure substances and compounds predicted the evaporation behavior of impurity elements and its compounds during the experimental process. Both Cu and Fe could partly evaporate into condensate and Cu had better evaporation ability than Fe. MoO3 could easily and Al2O3, SiO2 could partly evaporate into the condensate. Kilo-scale experiment was performed based on the small experiments and its results showed that the Mo content of molybdenum metal product was 92.38% and the S content of sulfur product was 96.28%, and the molybdenum recovery rate reached to 95.94%. Both the theoretical and experimental results proved that it was feasible to produce crude molybdenum and sulfur from molybdenite concentrate through vacuum decomposition. © 2015 Elsevier Ltd. All rights reserved. Source

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