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Journal of central south University 2015年第6期22卷 2385-2392页

作者：沈政昌陈建华张谌虎廖幸锦李玉琼 Machinery Research institute Beijing General Research Institute of Mining & Metallurgy College of Resources and metallurgy Guangxi University

According to the recently developed single-trough floating machine with the world's largest volume(inflatable mechanical agitation flotation machine with volume of 320 m3) in China, the gas-fluid two-phase flow in flotation cell was simulated using computational fluid dynamics method. It is shown that hexahedral mesh scheme is more suitable for the complex structure of the flotation cell than tetrahedral mesh scheme, and a mesh quality ranging from 0.7 to 1.0 is obtained. Comparative studies of the standard k-ε, k-ω and realizable k-ε turbulence models were carried out. It is indicated that the standard k-ε turbulence model could give a result relatively close to the practice and the liquid phase flow field is well characterized. In addition, two obvious recirculation zones are formed in the mixing zones, and the pressure on the rotor and stator is well characterized. Furthermore, the simulation results using improved standard k-ε turbulence model show that surface tension coefficient of 0.072, drag model of Grace and coefficient of 4, and lift coefficient of 0.001 can be achieved. The research results suggest that gas-fluid two-phase flow in large flotation cell can be well simulated using computational fluid dynamics method.

关键词： computational fluid dynamics (CFD) simulation flotation cell gas-liquid two-phases flow

Tungsten and arsenic substance flow analysis of a hydrometallurgical process for tungsten extracting from wolframite

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Tungsten 2021年第3期3卷 348-360页

作者： Yuan-Lin Chen Xue-Yi Guo Qin-Meng Wang Qing-Hua Tian Shao-Bo Huang Jin-Xiang Zhang School of metallurgy and Environment Central South UniversityChangsha 410083China Changsha Research institute of mining and metallurgy Co.LTD Changsha 410012China Ganzhou Nonferrous metallurgy Research institute Ganzhou 341000China

In this study,the metabolism of a hydrometallurgical process for tungsten extracting from wolframite was studied through substance flow *** mass balance accounts,substance flow charts of tungsten and arsenic were established to evaluate the metabolism efficiency of the investigated *** results showed that,the total tungsten resource efficiency of the system was 97.56%,and the tungsten recovery of unit process autoclaved alkali leaching,ion exchange,Mo removing,concentration and crystallization was 98.16%,98.94%,99.71%,99.89%,***,for extracting 1 ton of tungsten into the qualified ammonium paratungstate,10.0414 kg of arsenic was carried into the system,with the generation of 7.2801 kg of arsenic in alkali leaching residue,1.5067 kg of tungsten in arsenic waste residue,and 1.2312 kg of tungsten in Mo ***,7.9 g of arsenic was discharged into nature environment with waste water,15.5 g of arsenic was entrained into the final *** distribution and transformation behaviors of arsenic during production were analyzed through phases change analysis,and some recommendations for improving the resource efficiency of tungsten and pollution control during production were also proposed based on the substance flow analysis in this study.

关键词： Tungsten Arsenic Substance flow analysis Resource efficiency Pollution control

Superplastic behavior of a powder metallurgy superalloy during isothermal compression

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Journal of Materials Science & Technology 2019年第11期35卷 2591-2599页

作者： Liming Tan Yunping Li Feng Liu Yan Nie Liangjiang State Key Laboratory of Powder metallurgy Central South UniversityChangsha 410083China Powder metallurgy Research institute Central South UniversityChangsha 410083China High Temperature Materials Research institute Central South UniversityChangsha 410083China Yuanmeng Precision Technology(Shenzhen)institute Shenzhen 518000China

In this work,the flow behaviors and microstructure evolution of a powder metallurgy nickel-based superalloy during superplastic compression is *** on the strain rate sensitivity m determined by flow data,superplastic region is estimated at relatively low temperature and strain rate domains,specifically around 1000℃/10^-3s^-***,the cylinder specimens are isothermally compressed at 1000℃/10^-3s^-1 and 1025℃/10^-3s^-1 with different strains,to exam the superplasticity and related *** experimental results indicate that the accumulated dislocations are mainly annihilated by dynamic recovery and dynamic recrystallization(DRX),and the grain boundary sliding(GBS)contributes to the total strain during superplastic compression as *** addition,the cavities and cracks at triple junctions or interfaces between matrix and second phase particle have not been detected,which is different from superplastic tensile deformation.

关键词： Nickel-based superalloy Superplastic deformation Dynamic recrystallization Grain boundary sliding Hot compression

EFFECT OF MICROSTRUCTURES ON CYCLIC-OXIDATION BEHAVIOUR OF TiAl ALLOY

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中国有色金属学会会刊：英文版 1996年第2期6卷 91-94页

作者： Zhou Kechao Huang Baiyun Qu Xuanhui He Yuehui Kong Gaoning Powder metallurgy Research institute Central South University of TechnologyChangsha 410083

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关键词： γ-TiAl oxidation microstructure morphology Al_(2)O_(3) oxide scale

Oxidation behavior of CVI,MSI and CVI+MSI C/SiC composites

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Transactions of Nonferrous Metals Society of China 2010年第4期20卷 590-596页

作者：闫志巧陈峰熊翔肖鹏张红波黄伯云 Guangzhou Research institute of Nonferrous Metals State Key Laboratory for Powder metallurgy Central South University

The oxidation behavior of chemical vapor infiltration(CVI),molten silicon infiltration(MSI)and CVI+MSI C/SiC composites at 500-1 400℃was *** oxidation below 900℃increased successively for CVI,CVI+MSI and MSI ***,the oxidation of CVI composite above 1 000 ℃was much faster thanthat of MSI and CVI+MSI composites. As active carbon atoms produced by siliconization of fibers during MSI process were oxidized first and decreased initial oxidation *** initial oxidation temperature of MSI,MSI+CVI and CVI composites was 526,552 and 710℃,*** active carbon atoms were generated due to the breaking of 2D molecular chains during oxidation,so the activation energy of three C/SiC composites was decreased gradually at 500-800℃with oxidation process,exhibiting a self-catalytic characteristic.

关键词： chemical vapor infiltration(CVI) molten silicon infiltration(MSI) C/SiC composites oxidation

Microstructure and isothermal oxidation of 3Al_2O_3·2SiO_2/SiC coating on high and low density carbon-carbon composites

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Journal of central south University 2013年第1期20卷 30-36页

作者： L.GBOLOGAH 熊翔郝安林曾毅张武装 State Key Laboratory for Powder metallurgy Central South University Anyang institute of Technology

Carbon-carbon composite （C/C） materials are prone to severe oxidation and volatilization problems. To address these issues, mullite （3Al2O3.2SiO2）/silicon carbide （SIC） coatings were deposited on C/C composite substrates characterized into high and low densities. The coatings were applied by a two-step approach： pack cementation and silica sol based slurry coating processes. The relationship between the microstructure of 3Al2O3·2SiO2/SiC coatings and C/C substrates during isothermal oxidation cycle at 1 500 ℃ was investigated using X-ray diffractometer （XRD） and scanning electron microscope （SEM） mounted with energy dispersive spectrometer （EDS）. The results indicate that the density of the substrates has a marked effect on the coatings. Dense, thick and well-bonded coatings are obtained in the high density substrate. After 106 h of isothermal oxidation, the high density substrate with 3Al2O3-2SiO2/SiC coating offers effective protection as compared to low density substrate suffering recession.

关键词： mullite carbon-carbon composite slurry coating isothermal oxidation

A pure dielectric metamaterial absorber with broadband and thin thickness based on a cross-hole array structure

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Chinese Physics B 2022年第11期31卷 571-576页

作者： Wenbo Cao Youquan Wen Chao Jiang Yantao Yu Yiyu Wang Zheyipei Ma Zixiang Zhao Lanzhi Wang Xiaozhong Huang Powder metallurgy Research institute Central South UniversityChangsha 410083China State Key Laboratory of Powder metallurgy and Hunan Key Laboratory of Advanced Fibers and Composites Central South UniversityChangsha 410083China

A pure dielectric metamaterial absorber with broadband and thin thickness is proposed,whose structure is designed as a periodic cross-hole *** pure dielectric metamaterial absorber with high permittivity is prepared by ceramic reinforced polymer *** with those with low permittivity,the absorber with high permittivity is more sensitive to structural parameters,which means that it is easier to optimize the equivalent electromagnetic parameters and achieve wide impedance matching by altering the size or shape of the unit *** optimized metamaterial absorber exhibits reflection loss below-10 dB in 7.93 GHz–35.76 GHz with a thickness of 3.5 mm,which shows favorable absorption properties under the oblique incidence of TE polarization(±45°).Whether it is a measured or simulated value,the strongest absorbing peak reaches below-45 dB,which exceeds that of most metamaterial *** distributions of power loss density and electric and magnetic fields are investigated to study the origin of their strong absorbing *** resonance mechanisms are proposed to explain the phenomenon,including polarization relaxation of the dielectric and edge effects of the cross-hole *** work overcomes the shortcomings of the narrow absorbing bandwidth of *** demonstrates that the pure dielectric metamaterial absorber with high permittivity has great potential in the field of microwave absorption.

关键词： dielectric metamaterial absorber

Structural self-reconstruction strategy empowering Ni-rich layered cathodes with low-strain for superior cyclabilities

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Nano Research 2023年第4期16卷 4950-4960页

作者： Zhouliang Tan Yunjiao Li Xiaoming Xi Shijie Jiang Xiaohui Li Xingjie Shen Panpan Zhang Zhenjiang He School of metallurgy and Environment Central South UniversityChangsha 410083China Engineering Research Center of the Ministry of Education for Advanced Battery Materials Central South UniversityChangsha 410083China Changsha Research institute of mining and metallurgy Changsha 410083China Office of Laboratory and Equipment Management Xinjiang UniversityUrumqi 830000China

The key to hindering the commercial application of Ni-rich layered cathode is its severe structural and interface degradation during the undesired phase transition(hexagonal to hexagonal(H2→H3)),degenerating from the build-up of mechanical strain and undesired parasitic ***,a perovskite Li_(0.35)La_(0.55)TiO_(3)(LLTO)layer is built onto Ni-rich cathodes crystal to induce layered@spinel@perovskite heterostructure to solve the root cause of capacity *** exploration based on structure characterizations,in situ X-ray diffraction techniques,and first-principles calculations demonstrate that such a unique heterostructure not only can improve the ability of the host structure to withstand the mechanical strain but also provides fast diffusion channels for lithium ions as well as provides a protective barrier against electrolyte ***,the LLTO modified LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)cathode manifests an unexpected cyclability with an extremely high-capacity retention of≈94.6%after 100 cycles,which is superior to the pristine LiNi_(0.9)Co_(0.05)Mn_(0.05)O_(2)(79.8%).Furthermore,this modified electrode also shows significantly enhanced cycling stability even withstanding a high cut-off voltage of 4.6 *** surface self-reconstruction strategy provides deep insight into the structure/interface engineering to synergistically stabilize structure stability and regulate the physicochemical properties of Ni-rich cathodes,which will also unlock a new perspective of surface interface engineering for layered cathode materials.

关键词： Ni-rich layered oxides cathode structural self-reconstruction phase transition mechanical strain first-principal calculation

Hydrogen Energy Demand Management in China:A Department Scenario Analysis Method

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Energy Engineering 2025年第3期122卷 971-983页

作者： Zhongxun Li Bing Wang Xiaolin Liu Center for Sustainable Development and Energy Policy Research School of Energy and Mining EngineeringChina University of Mining and Technology-BeijingBeijing100083China Research institute of Decision-Making Science and Big Data School of ManagementChina University of Mining and Technology-BeijingBeijing100083China

The proposal of carbon neutrality target makes decarbonization and hydrogenation typical features of future energy development in *** a wide range of application scenarios,hydrogen energy will experience rapid growth in production and *** formulate an effective hydrogen energy development strategy for the future of China,this study employs the departmental scenario analysis method to calculate and evaluate the future consumption of hydrogen energy in China’s heavy industry,transportation,electricity,and other related *** technical parameters are selected and predicted accurately and reliably in combination with different development *** findings indicate that the period from 2030 to 2050 will enjoy rapid development of hydrogen energy,having an average annual growth rate of 2%to 4%.The technological progress and breakthroughs scenario has the greatest potential for hydrogen demand scale among the four development *** this scenario,the total demand for hydrogen energy is expected to reach 446.37Mt in *** sector will be the sector with the greatest potential for hydrogen deployment growth from 2023 to 2060,which is expected to rise from 0.038Mt to about 163.18Mt,with the ambitious growth in the ***,hydrogen energy has a considerable development potential in the steel sector,and the trend of de-refueling coke by hydrogenation in this sector will be imperative for this energy-intensive industries.

关键词： Hydrogen demand management department scenario analysis carbon neutrality

Microstructure and mechanical properties of Al-Si-Ni coating on Cu-Cr substrate prepared by multi-permeation and friction stir processing

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Nano Materials Science 2019年第3期1卷 224-228页

作者： Yin Wang Ruidi Li Tiechui Yuan State Key Laboratory of Powder metallurgy Shenzhen Institute of Central South University Central South University

The surface of copper-chromium alloy was processed by Al-Si-Ni multi-permeation and friction stir processing,and the microstructure and mechanical properties of the surface layer were tested by scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),microhardness tester and friction testing *** results show that Al,Si and Ni elements are fully permeated into the surface of copper-chromium alloy after multielement co-infiltration and friction stir *** the observation of the microstructures,we found that the reticular structure is fragmented and distributed in the stir zone *** becomes finer and grains *** micro hardness of the copper-chromium alloy increased to 129 HV,44.9%higher than that of the original *** main reasons of microhardness enhancement are solid solution strengthening,fine grains strengthening and dispersion *** friction test results show that the friction coefficient is basically stable at 0.69 and the wear mass is only 0.0017 g after 10 min of friction *** improvement of wear resistance was attributed to the increase of microhardness of the alloy surface.

关键词： Copper-chromium alloy Al-Si-Ni multi-permeation Friction stir processing Microstructure Mechanical properties