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Zuo Y.-J.,Guizhou University | Zuo Y.-J.,Guizhou Engineering Laboratory of Mineral Resources | Zuo Y.-J.,Engineering Center for Safe Mining Technology Under Complex Geologic Condition | Jia P.,Northeastern University China | And 2 more authors.
Advances in Mechanical Engineering | Year: 2013

Three-dimensional numerical tests have been conducted to investigate the failure process of surrounding rock mass around circular and U-shaped tunnel at depth. Different failure modes of deep underground openings have been reproduced. The influence of different shapes and sizes of tunnel section, as well as the direction of the maximum principal stress, on zonal disintegration was analyzed. Numerical simulations show that failure modes and load-bearing capacity of tunnel depend on the direction of the maximum principal stress. The zonal disintegration around deep underground openings is a phenomenon that only occurs under some special conditions. Firstly, there must be a higher horizontal tectonic stress along the axial direction of tunnel; secondly, the radius of curvature of tunnel should be large enough to induce the tensile stress higher than tensile strength of rock mass. Therefore, the direction of tunnel axis as well as the direction and the size of tectonic stress should be carefully considered during tunnel design. © 2013 Yu-Jun Zuo et al. Source


Tuo B.,Guizhou University | Wang J.,Hunan University of Technology | Yao Y.,Guizhou University | Han L.,Guizhou Engineering Laboratory of Mineral Resources | And 2 more authors.
ISIJ International | Year: 2015

The influence of different reactivity coke on reduction, softening, melting and dropping properties of iron-bearing burden were studied by melting and dropping experiment, meanwhile reduction mechanism and softening-melting mechanism of stock column, as well as stock column pressure difference were also analyzed. The results show that reduction degree at 1 000°C increases, softening-melting start temperature and dropping temperature decrease, and melting temperature rises, when the coke reactivity increases from 24.76% to 56.28%. Softening and melting temperature interval increases, melting and dropping temperature interval reduces and stock column permeability is improved as the coke reactivity increased, which lead to softening-melting and dropping properties value of iron-bearing burden reducing. In addition, industrial experimental analysis shows that reducing agent rate (RAR) can be reduced by 8.26 kg/t using high reactivity coke (HRC) of 12%. Therefore, the appropriate increase of coke reactivity could improve stock column permeability and high temperature properties of iron-bearing burden, so as to reduce RAR. © 2015 ISIJ. Source


Zhang Y.-S.,Guizhou University | Zhang Y.-S.,Guizhou Provincial Key Laboratory of Comprehensive Utilization of Non metallic Mineral Resources | Zhang Y.-S.,Guizhou Engineering Laboratory of Mineral Resources | Zhang J.,Guizhou University | And 2 more authors.
Chinese Rare Earths | Year: 2015

Field sampling, chemical analysis, X-ray diffraction, scanning electron microscope, X -ray diffraction component analysis and electron probe microanalysis for lateritic type titanium ore in Fuyuan were conducted. The results show that the types of the ore is anatase ore and anatase - containing hematite ore, and the grade of TiO2 is 3.65 %~5.22%. Rare earth characteristic values were contrasted. LREE/HREE were 2.88 and 3.68, La/Yb were 5.54 and 10.03, which indicated that the light rare earth in samples was significantly enriched, the same to Y element. δCe value of 0.85 and 0.93 showed negative anomaly. δEu value of 0.97 and 1.07 showed weakly positive anomaly. The diagram of trace element distribution patterns of Fuyuan titanium ore samples showed that its distribution characteristics had homology. By studying the rare earth and trace element geochemical characteristics and the inheritance of rare earth elements in the process of alteration, it is concluded that Emeishan basalts has provided material sources for titanium mineralization. ©, 2015, Editorial Office of Chinese Rare Earths. All right reserved. Source


Zhang Y.,Guizhou University | Zhang Y.,Guizhou Engineering Laboratory of Mineral Resources | Zhang Y.,Engineering Center for Safe Mining Technology Under Complex Geologic Condition | Zuo Y.-J.,Guizhou University | And 2 more authors.
Dongbei Daxue Xuebao/Journal of Northeastern University | Year: 2015

The numerical tests were run with a Rock Failure Process Analysis code, F-RFPA2D, incorporated with a Flow-Stress-Damage coupling model (FSD). By numerical simulation of failure process of rock sample containing two pre-existing closed flaws under different directions of hydraulic pressure, to investigate the crack initiation and propagation. This will be conducive to the understanding of crack extension in fractured rock mass, rock damage fracture coalescence mechanism, explicit interaction with the seepage mechanism. The simulated results reveal that the confining pressure can cause the transition from tensile rupture mode to shear fracture mode, and vice versa for seepage. When the water pressure gradient direction and the external load direction are the same, the flow of water will promote crack propagation along the flow direction; when the two are in the opposite direction, the crack will transit from compressive stress mode to tensile stress mode and the rock mass is more prone to rupture. ©, 2015, Northeastern University. All right reserved. Source


Tuo B.Y.,Guizhou University | Tuo B.Y.,Guizhou Engineering Laboratory of Mineral Resources | Wang J.L.,Hunan University of Technology | Yao Y.L.,Guizhou University | And 2 more authors.
Advanced Materials Research | Year: 2014

Ti-PILCs (Ti-pillared Montmorillonite Nanocomposites) was obtained from which Ti(n-C4H9O)4 cross-linked Na-montmorillonite through Sol-gel means. The analysis results of BET, FT-IR and TG-DSC shows that a large amount of middle porous of 2-4nm exist in the Ti-PILCs interlayer and the porous distributing is not uniformity, meanwhile, the thermal stability is over 900 °C. It has good application prospect to use as carrier materials material of oil catalytic and cracking. © (2014) Trans Tech Publications, Switzerland. Source

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