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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.

Xiong H.,National Engineering Laboratory for Vacuum Metallurgy | Xiong H.,Key Laboratory of Vacuum Metallurgy for Non Ferrous Metal of Yunnan Province | Xiong H.,State Key Laboratory of Complex Non ferrous Metal Resources Clear Utilization in Yunnan Province | Yang B.,National Engineering Laboratory for Vacuum Metallurgy | And 14 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2014

A novel environmental firendly techniquie was developed to separate lead and antimoney from Jamesonite by vacuum evaporation. The impacts of the distillation conditions, such as the distillation temperature and time, pressure, and energy consumption, on the separation rates of lead and antimony were experimentally investigated. The contents of the condensed volatiles and slag were characterized with X-ray diffraction, and conventional chemical analysis. The preliminary results show that the newly-developed vacuum distillation is feasible to separate lead and antimony from jamesonite, and that the distillation temperature and time have a major impact on the separation. For example, at a distillation temperature ranging from 1200℃ to 1400℃, theseparation rates of lead and antimony were found to be higher than 99%. Besides, an increase of distillation time also weakly increased the separation rates. The multistage condenser is capable of enriching lead and antimony, respectively. The advantages of the novel technique over the conventional one on industrial scale were also tentatively discussed.

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