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Xiong H.,State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization | Xiong H.,National Engineering Laboratory for Vacuum Metallurgy | Yang B.,National Engineering Laboratory for Vacuum Metallurgy | Dong Z.,National Engineering Laboratory for Vacuum Metallurgy | And 4 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2016

Here, we experimentally addressed the extraction of Pb and Sb from jamesoniteconcentrate by vacuum distillation. The influence of the distillation conditions, including but not limited to the distillation temperature, distillation time and pressure, on the removal of Pb and Sb was investigated with X-ray diffraction, titrametric analysis and atomic absorption spectrometry (AAS). The preliminary results show that depending strongly on the distillation temperature and time, vacuum distillation is capable of removing most Pb and Sb from jamesonite in a simple and environmental friendly way. To be specific, distilled at 1523 K for 60 min, over 99% of both Pb and Sb were removed from the jamesonite, and most Fe stayed in the slag, existing in FeS-phase, because of poor volatilization of Fe. © 2016, Science Press. All right reserved.


Jia J.,National Engineering Laboratory for Vacuum Metallurgy | Jia J.,Key Laboratory for Nonferrous Metals Vacuum Metallurgy of Yunnan Province | Jia J.,Kunming University of Science and Technology | Xu B.,National Engineering Laboratory for Vacuum Metallurgy | And 11 more authors.
JOM | Year: 2013

Preparation of Ti powders from TiO2 by calcium vapor reduction was investigated by x-ray diffraction (XRD), scanning electron microscope (SEM), element analysis instrument, inert gas fusion-infrared absorption spectroscopy, and ethylene diamine tetraacetic acid (EDTA) complex formation titration. The experimental results indicate that the reduction reaction occurs very rapidly when the mass ratio of CaCl2 to TiO2 is 1:2 from 0 min to 30 min, and the titanium suboxides were further reduced from 30 min to 480 min at 1000 C. The content of CaCl2 influences the reduction products and the reduction rate obviously, and the suitable mass ratio of CaCl2 to TiO2 is 1:2 under these experimental conditions. Ti powders with oxygen content of 1000 ppm, nitrogen content of 120 ppm, and chlorine content of 80 ppm were obtained at 1000 C for 360 min. © 2013 TMS.


Sun H.,National Engineering Laboratory for Vacuum Metallurgy | Sun H.,Kunming University of Science and Technology | Sun H.,Honghe University | Ma W.,National Engineering Laboratory for Vacuum Metallurgy | And 7 more authors.
Vacuum | Year: 2012

Thin films of solid electrolyte La 0.9Sr 0.1Ga 0.8Mg 0.2O 3-δ (LSGM) were deposited by RF magnetron sputtering onto porous La 0.7Sr 0.3Cr 0.5Mn 0.5O 3-δ (LSCM) anode substrates. The effects of substrate temperature, sputtering power density and sputtering Ar gas pressure on the LSGM thin film density, flatness and morphology were systematically investigated. RF sputtering power density of 7.8 W cm -2, substrate temperature of 300°C and sputtering Ar gas pressure of 5 Pa are identified as the best technical parameters. In addition, a three-electrode half cell configuration was selected to investigate the electrochemical performance of the thin film. The LSGM film deposited at optimum conditions exhibited a lower area specific ohmic resistance of 0.68 Ω cm -2 at 800°C, showing that the practicability of RF magnetron sputtering method to fabricate LSGM electrolyte thin film on porous LSCM anode substrates. © 2011 Elsevier Ltd. All rights reserved.


Sun H.-Y.,Honghe University | Sen W.,Yunnan Tin Company Ltd | Ma W.-H.,National Engineering Laboratory for Vacuum Metallurgy | Yu J.,National Engineering Laboratory for Vacuum Metallurgy | Yang J.-J.,National Engineering Laboratory for Vacuum Metallurgy
Rare Metals | Year: 2014

La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) and La0.7Sr0.3Cr0.5Mn0.5O3-δ (LSCM) powders were synthesized by glycine-nitrate process, and LSGM electrolyte thin film was successfully fabricated on porous anode substrate of LSCM by slurry spin coating technology. Some technical parameters for the preparation of LSGM thin films were systematically investigated, including ink composition, sintering temperature, and spin coating times. The electrolyte films with the best compactness and somewhat rough are obtained when the operating parameters are fixed as follows: the content of ethyl cellulose as binder is 5 wt%, the content of terpineol as modifier is 5 wt%, the optimum coating cycle number is 9 times, and the best post-deposition sintering temperature is 1,400 °C for 4 h. © 2014 The Nonferrous Metals Society of China and Springer-Verlag Berlin Heidelberg.


Yang J.,National Engineering Laboratory for Vacuum Metallurgy | Yang J.,Kunming University of Science and Technology | Ma W.,National Engineering Laboratory for Vacuum Metallurgy | Ma W.,Kunming University of Science and Technology | And 7 more authors.
Journal of Rare Earths | Year: 2013

La0.9Sr0.1Ga0.8Mg0.2O 3-δ (LSGM) electrolyte materials were synthesized by the solid state reaction method. The conductivity of LSGM materials was detected by four probe method, and it was 0.08 S/cm at 850 °C. Dense and uniform films of LSGM materials were deposited by the magnetic sputtering on substrates of Si and La0.7Sr0.3Cr0.5Mn0.5O 3-δ (LSCM). The experimental results showed that the deposition rates dropped and the average grain sizes of the films enlarged with increase in the substrate temperatures. In the sputtering process, the LSGM film was deposited with preferred growth direction. After annealing, the preferred growth direction disappeared and the film surface became smoother and denser. Through observing the deposition process, deposition mechanism was proposed, which was consistent with a model of island growth.


Tian Y.,National Engineering Laboratory for Vacuum Metallurgy | Tian Y.,Kunming University of Science and Technology | Liu H.,National Engineering Laboratory for Vacuum Metallurgy | Liu H.,Kunming University of Science and Technology | And 4 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2012

Magnesium metal was extracted from magnesia by carbothermic reduction in vacuum. The Mg condensates were characterized with X-ray diffraction and scanning electron microscopy. The impacts of extraction conditions, including the pressure, temperature, molar ratio, carbothermic time and content of the catalyst, compactness of magnesia grains, etc., on the Mg reduction rate and reactant weight loss were evaluated. The results show that the newly-developed Mg vacuum extraction technique does a good job, and that the extraction conditions strongly affect the Mg extraction rate and reactant weight loss. For instance, at a temperature over 1553 K, a pressure ranging 30~100 Pa, and with the grains compressed at 8 MPa, the largest reactant weight losses were obtained, resulting in the highest Mg reduction rate. As the molar ratio of C/MgO and reaction time increased, the rates of both carbothermic reaction and Mg reduction increased slowly. Addition of CaF 2 significantly increased the reactant weight loss. When CaF 2 accounted for 3% of the total weight, the weight loss rate increased up to 95%, coinciding with a large Mg reduction rate.


Li Y.,National Engineering Laboratory for Vacuum Metallurgy | Li Y.,Kunming University of Science and Technology | Yu Q.,National Engineering Laboratory for Vacuum Metallurgy | Yang B.,National Engineering Laboratory for Vacuum Metallurgy | And 2 more authors.
Zhenkong Kexue yu Jishu Xuebao/Journal of Vacuum Science and Technology | Year: 2012

Here, we addressed the vacuum decomposition of kaolin, mainly consisting of kaolinite, diaspore, and pyrite, to explore the possible applications of the decomposed compounds. The impacts of The decomposition conditions, such as the decomposition temperature and time, pressure, and impurities, on microstructures and stoichiometries of the decomposed compounds were evaluated with scanning electron microscopy, X-ray diffraction and differential scanning calorimetry-Thermogravimetric analysis. The results show that the low pressure strongly affects the dehydration of diaspore and decomposition of pyrite. For instance, at a pressure of 15~50 Pa, starting at 100°C, The complete dehydration of the diaspore occurred at 300°C. At a temperature ranging from 500°C~600°C, The decomposition of the pyrite into FeS and S 2 took place, and completed at 700°C. The dehydration temperature of kaolinite into metakaolinite was about 200~300°C, 200°C lower than that at atmospheric pressure. The experimental data agree fairly well with the calculated results based thermodynamics at a pressure from 10 5 Pa to 50 Pa. We found that the decomposition sequence of the three main components little affects the decomposition of the kaolin.


Sen W.,National Engineering Laboratory for Vacuum Metallurgy | Sen W.,Key Laboratory of Vacuum Metallurgy for Nonferrous Metal of Yunnan Province | Sen W.,Kunming University of Science and Technology | Xu B.-Q.,National Engineering Laboratory for Vacuum Metallurgy | And 11 more authors.
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2011

The preparation of fine TiC powders by carbothermal reduction of TiO 2 in vacuum was investigated by XRD, SEM, XRF and laser particle sizer. Thermodynamic analysis indicates that it is easy to prepare TiC in vacuum and the formation sequence of products are Ti4O7 (Magneli phase), Ti3O5, Ti2O3, TiC xO1-x and TiC with the increase of reaction temperature. Experimental results demonstrate that TiC powders with single phase are obtained with molar ratio of TiO2 to C ranging from 1:3.2 to 1:6 at 1 550 °C for 4 h when the system pressure is 50 Pa, and TiC1.0 is gained when the molar ratio of TiO2 to C is 1:4 and 1:5. In addition, fine TiC1.0 powders (D50 equals 3.04 μm) with single phase and low impurities are obtained when the molar ratio of TiO2 to C is 1:4. SEM observation shows that uniform shape, low agglomeration, and loose structure are observed on the surface of block product. © 2011 The Nonferrous Metals Society of China.


Jia J.,National Engineering Laboratory for Vacuum Metallurgy | Xu B.,Key Laboratory for Nonferrous Metals Vacuum Metallurgy | Yang B.,Kunming University of Science and Technology | Wang D.,National Engineering Laboratory for Vacuum Metallurgy | And 2 more authors.
Key Engineering Materials | Year: 2013

Preparing titanium powders by calcium vapor reduction of titanium oxide directly is a new way with short flow sheet and CaTiO3 is the very important intermediate compound in this process. In this paper, the behavior of intermediate CaTiO3 in the reduction process of TiO2 was investigated. The thermodynamic calculation indicated that the Gibbs free energy change of the reaction to produce CaTiO3 by CaO and TiO2 was always negative below 1000 °C; The reaction Gibbs free energy change of the calciothermic reduction of CaTiO3 was lower than that of TiO, which would be the most predominant step from TiO2 to Ti. The experimental results showed that CaTiO3 phase derived from the reaction between TiO2 and the reduction by-product CaO, and the reaction between TiO2 and the decomposition product CaO from the additive of CaCl2 with crystal water as well in the calcium vapor reduction process of titanium oxide. But CaTiO3 could be reduced to Ti much easier than that of TiO2 by calcium vapor. Copyright © 2013 Trans Tech Publications Ltd.


Sun H.,National Engineering Laboratory for Vacuum Metallurgy | Sun H.,Kunming University of Science and Technology | Ma W.,National Engineering Laboratory for Vacuum Metallurgy | Ma W.,Kunming University of Science and Technology | And 5 more authors.
Journal of Rare Earths | Year: 2010

The La0.8Sr0.04Ca0.16Co 0.6Fe0.4O3-δ (LSCCoF) and La 0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) powders were synthesized by glycine-nitrate combustion process and conventional solid-state reaction method, respectively. The LSCCoF-LSGM composite cathode material was successfully elaborated and deposited on dense pellets of the LSGM electrolyte by means of slurry spin-coating process. The cathode films with the best surface morphology and microstructure were obtained when the operating parameters fixed as follows: the content of ethyl cellulose which acted as pore former and binder is 10 wt., the content of terpineol which acted as modifier is 5 wt., the speed of rotation rate is 3200 r/min and the best post-deposition sintering temperature is 1000 °C. © 2010 The Chinese Society of Rare Earths.

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