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Xiao Y.,Yunnan University | Chen X.,Yunnan University | Ma W.,Kunming University of Science and Technology | Ma W.,State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization | And 5 more authors.
International Journal of Materials Research | Year: 2015

Large-area and oriented silicon nanowire arrays have been successfully fabricated through a two-step metal-assisted chemical etching process at room temperature. The effects of key fabrication parameters (AgNO3 concentration, Fe(NO3)3 concentration, and etching time) on the silicon nanowire nanostructure were carefully investigated. The Raman spectra of silicon nanowires prepared under different etching times have been recorded and analyzed. The porosity and length of the nanowire increases with the increase in AgNO3 concentration from 0.002 mol L-1 to 0.1 mol L-1, which indicates that the re-dissolved Ag+ ions would work as the main oxidative species and catalyze the vertical and lateral etching of nanowires, leading to silicon nanowire growth and porous structure formation. © Carl Hanser Verlag GmbH & Co. KG. 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


Kong X.,National Engineering Laboratory for Vacuum Metallurgy | Kong X.,Central South University | Kong X.,State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization | Xiong H.,National Engineering Laboratory for Vacuum Metallurgy | And 15 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2014

Removal of arsenic from high-arsenic crude lead by vacuum distillation was modeled, theoretically calculated, and experimentally evaluated. The effects of the distillationconditions, including the pressure, distillation temperature and time, on the removal rate of arsenic and direct recovery of lead were examined. The calculated results show that vacuum distillation is feasible to effectively remove arsenic from crude lead with high arsenic impurity at a moderate temperature because at a given elevated temperature, the saturated vapor pressure of arsenic is much higher than that of lead, and because arsenic and lead cannot form an intermetallic compound. The vacuum distillation was experimentally tested. Distilled at a pressure of 5 to 15 Pa and at 973 K for 30 min, the removal rate of arsenic and direct recovery rate of lead were found to be 80% and 97%, respectively. Besides, copper impurity was found to negatively affect the removal of arsenic because copper and arsenic form an intermetallic compound. ©, 2014, Science Press. All right reserved. Source


Song B.,Kunming University of Science and Technology | Song B.,Key Laboratory for Nonferrous Vacuum Metallurgy of Yunnan Province | Song B.,State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization | Jiang W.,Kunming University of Science and Technology | And 8 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2015

Separation of the Pb-Sb alloy by vacuum distillation, an environmental pollutantproduced in Pb and Sb smelting slag and in their consumption, was mathematically modeled, theoretically analyzed in thermodynamics and experimentally evaluated. The separation coefficient of Sb, contents of Pb and Sb in volitile and residue were estimated by plotting the vapor-liquid equilibrium composition diagram of the Pb-Sb alloy in 923~1373 K range. The calculated results show that vacuum distillation is capable of separating Pb and Sb. The influence of the distillation conditions, including the temperature, distillation time, contents of Pb and Sb in the raw Pb-Sb alloy, on the volatilization rates of Pb and Sb were experimentally investigated. Distilled at 5~10 Pa and 973 K for 30 min, the Sb-content was found to be 57.44% in the volatile and crude Pb-content was estimated to be 88.82% in residue. © 2015, Science Press. All right reserved. Source


Kong X.-F.,Kunming University of Science and Technology | Kong X.-F.,Central South University | Kong X.-F.,State Key Laboratory of Complex Nonferrous Metal Resources Clear Utilization | Yang B.,Kunming University of Science and Technology | And 9 more authors.
Journal of Central South University | Year: 2014

The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as (3-Mercaptopropyl) triethoxysilane (MPTES) and (3-Amincpropyl) trithoxysilane (APTES). Some further modifications were studied by chloroaceetyl choride and 1,8-Diaminoaphalene for amino modified silica. The surface functionalized silica nanoparticles were characterized by Fourier transform infrared (FI-IR) and X-ray photoelectron spectroscopy (XPS). The prepared adsorbent of surface functionalized silica nanoparticles with differential function groups were investigated in the selective adsorption about Pb2+, Cu2+, Hg2+, Cd2+ and Zn2+ ions in aqueous solutions. The results show that the (3-Mercaptopropyl) triethoxysilane functionalized silica nanoparticles (SiO2-MPTES) play an important role in the selective adsorption of Cu2+ and Hg2+, the (3-Amincpropyl) trithoxysilane (APTES) functionalized silica nanoparticles (SiO2-APTES) exhibited maximum removal efficiency towards Pb2+ and Hg2+, the 1,8-Diaminoaphalene functionalized silica nanoparticles was excellent for removal of Hg2+ at room temperature, respectively. © 2014, Central South University Press and Springer-Verlag Berlin Heidelberg. Source

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