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Oxide coating mechanism during fluidized bed reduction: solid-state reaction characteristics between iron ore particles and MgO

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International Journal of Minerals,Metallurgy and Materials 2016年第9期23卷 1019-1028页

作者： Lei Guo jin-tao gao Yi-wei Zhong Han gao Zhan-cheng Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Experiments on the solid-state reaction between iron ore particles and MgO were performed to investigate the coating mechanism of MgO on the iron ore particles＇ surface during fluidized bed reduction. MgO powders and iron ore particles were mixed and compressed into briquettes and, subsequently, roasted at different temperatures and for different time periods. A Mg-containing layer was observed on the outer edge of the iron ore particles when the roasting temperature was greater than 1173 K. The concentration of Fe in the Mg-containing layer was evenly distributed and was approximately 10wt%, regardless of the temperature change. Boundary layers of Mg and Fe were observed outside of the iron ore particles. The change in concentration of Fe in the boundary layers was simulated using a gas–solid diffusion model, and the diffusion coefficients of Fe and Mg in these layers at different temperatures were calculated. The diffusion activation energies of Fe and Mg in the boundary layers in these experiments were evaluated to be approximately 176 and 172 k J/mol, respectively.

关键词： fluidized beds coating solid reaction ferric oxide magnesia diffusion coefficient

Phosphorus migration mechanism between iron and high phosphorus gangue phase at high temperatures

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Journal of Iron and Steel Research International 2019年第2期26卷 113-122页

作者： Lei Guo jin-tao gao Sheng-ping Zhong Zhan-cheng Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The phosphorus migration mechanism during melting separation of non-carbon-reduced high phosphorus iron ore was ***,the equilibrium compositions of hydrogen-reduced high phosphorus iron ore at different temperatures were simulated by the use of equilibrium composition module of HSC Chemistry ***,thermodynamic calculation was verified by the real heat treatment of simulated hydrogen-reduced high phosphorus iron ore with several pure reagents including self-made pure *** iron particles in the simulated samples gathered and grew up during heat ***,the hypoeutectic structure of Fe-P with grid shape of high phosphorus phase and circular shape of low phosphorus phase emerged within those iron *** the penetration of phosphorus from the periphery into the iron particles,the grid structure became denser and *** proves that the elemenlal phosphorus can be reduced from the gangue phase by metallic iron without solid carbon at high temperatures.

关键词： Melting separation Fluorapatite Thermodynamics Phosphorus migration High phosphorus iron ore

Removal of phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super-gravity field

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International Journal of Minerals,Metallurgy and Materials 2016年第7期23卷 743-750页

作者： jin-tao gao Lei Guo Yi-wei Zhong Hong-ru Ren Zhan-cheng Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

A new approach of removing the phosphorus-rich phase from high-phosphorous iron ore by melt separation at 1573 K in a super-gravity field was investigated. The iron？slag separation by super-gravity resulted in phosphorus being effectively removed from the iron-rich phase and concentrated as a phosphorus-rich phase at a temperature below the melting point of iron. The samples obtained by super-gravity exhibited obvious layered structures. All the iron grains concentrated at the bottom of the sample along the super-gravity direction, whereas the molten slag concentrated in the upper part of the sample along the opposite direction. Meanwhile, fine apatite crystals collided and grew into larger crystals and concentrated at the slag–iron interface. Consequently, in the case of centrifugation with a gravity coefficient of G = 900, the mass fractions of the slag phase and iron-rich phase were similar to their respective theoretical values. The mass fraction of MFe in the iron-rich phase was as high as 97.77wt% and that of P was decreased to 0.092wt%.

关键词： ironmaking super-gravity melt separation dephosphoration

In situ observation of iron ore particle reduction above 1373K by confocal microscopy

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Journal of Iron and Steel Research International 2019年第1期26卷 32-41页

作者： Lei Guo jin-tao gao Sheng-ping Zhong Qi-peng Bao Zhan-cheng Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

The reduction behavior of single iron ore particle was investigated at high temperatures(above 1373 K)with CO/CO2 mixture.A high-temperature laser scanning confocal microscope for in situ observation and a vertical quenching furnace for offline characterization were *** reduction process of ore particles at different temperatures and in different atmospheres was videoed using the confocal *** the temperature range studied,the transformation of Fe2O3-FeO firstly occurred in the ore particles,and there was no metallic iron until the ore particles completely converted to FeG *** the formation of FeO phase,its crystal lattice transforms along the most close-packed direction of its close-packed plane(111).The gangue-rich area firstly melts during reduction around 1573 *** 1673 K,the iron ore particles melt and form spherical liquid drops with metallic iron in the *** gas-based reduction behavior of iron ore particles above 1373K is deduced and graphically presented.

关键词： In situ observation Iron ore particle Reduction Transformation Non-blast furnace

Evolution of microstructure,mechanical and magnetic properties of electrodeposited 50% Ni-Fe alloy foil after thermal treatment

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Journal of Iron and Steel Research International 2017年第8期24卷 844-851页

作者： Hong-ru Ren jin-tao gao Zhe Wang Chong Li Fu-qiang Wang Zhan-cheng Guo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

In order to expand the application of the electrodeposited Ni-Fe alloy foil,their mechanical and magnetic properties were studied after heat *** development of grain growth during annealing was in-situ online investigated using a heating stage microscope,and the texture was analyzed via X-ray diffraction（XRD）and electron back-scattered diffraction（EBSD）.The results indicated that abnormal grain growth usually occurred during annealing at 1000-1050°***{111}oriented grains preferentially grew as the annealing temperature and holding time *** plasticities of the electrodeposited Ni-Fe alloy foils after heat treatment were better than those of the original *** excellent ductility was obtained without a loss in magnetic properties after annealing at 1100°C for 6h.

关键词： Electrodeposited Ni-Fe alloy foil Mechanical property Magnetic property Annealing

Local magnetic moment oscillation around an Anderson impurity on graphene

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 192-201页

作者： Shuai Li Zhen Ma jin-Hua gao School of Science Hebei University of Science and Technology School of Electronics and Information Zhengzhou University of Light Industry School of Physics and Wuhan National High Magnetic Field Center Huazhong University of Science and Technology

We theoretically investigate the spin resolved Friedel oscillation （FO） and quasiparticle interference （QPI） in graphene induced by an Anderson *** the impurity becomes magnetic,the resulted FO becomes spin dependent,which gives rise to a local magnetic moment oscillation with an envelop decaying as r-2in real space in the doping ***,at half filling,the electron density and local magnetic moment will not oscillate but decay as *** spin resolved FO has both sublattice and spin ***,the local magnetic moment decay at half filling only occurs at one sublattice of graphene,which is quite like the phenomenon observed in the STM experiment (***ález-Herrero et al.,Science 352,437 （2016）).We further give an analytic formula about such spin dependent FO based on the stationary phase ***,we study the interference of quasiparticles around the magnetic impurity by calculating the spin dependent Fourier-transformed local density of states （FT-LDOS）.Our work gives a comprehensive understanding about the local magnetic moment oscillation around an Anderson impurity on graphene.

关键词： Friedel oscillation local magnetic moment graphene Anderson impurity

Development of Temperature-Humidity Independent Control Air-Conditioning Unit for Residential Buildings

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湖南大学学报（自然科学版） 2009年第S1期36卷 83-87页

作者： HAN Xing1,ZHANG Xu1,LIU jin-tao2,gao Si-yun2,KANG Yue2(1.Institute of HVAC & Gas,College of Mechanical Engineering,Tongji University,Shanghai 200092,China 2.Hisense R&D Center,Qingdao,266000,China) Institute of HVAC and Gas College of Mechanical Engineering Tongji University Shanghai 200092 China Hisense R and D Center Qingdao 266000 China

Cooling panels are increasingly used in domestic residential *** provide medium temperature cold water for the cooling panel,and dehumidify the indoor air simultaneously,a new kind of temperature-humidity independent control air-conditioning unit was developed for single residential house by utilizing multi-variable ***,the supply air temperature was studied to determine the proper supply air flow rate for the humidity ***,the energy consumption of different temperature-humidity independent control systems was *** analysis indicates that unity evaporating temperature can be used to handle the moisture load and sensible heat load in two *** the unit scheme was put *** evaporators were used to produce medium temperature water and dry air separately,and electric expansion valves were used to control the refrigerant distribution between the two ***,experimental work was carried out to investigate the influence of compressor frequency,refrigerant distribution on the dehumidification capacity,energy efficiency and refrigeration *** the end,the paper concludes that both compressor frequency and refrigerant distribution can control the dehumidification capacity,but the former influences the EER more than the latter,while the latter influences the refrigeration capacity more than the *** can find a proper running point at certain sensible and latent cooling load by adjusting both compressor frequency and electric expansion *** energy consumption of this kind of unit was estimated and compared with present room air conditioners,which shows that it can save about 41% cooling energy consumption.

关键词： temperature-humidity independent control residential buildings cold dehumidification experimental study

QuEChERS-超高效液相色谱-串联质谱法测定双氟磺草胺和氯氟吡氧乙酸在小麦和土壤中的残留及消解动态

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农药学学报 2018年第4期20卷 468-476页

作者：金涛段劲生高同春安徽省农业科学院植物保护与农产品质量安全研究所农业部农产品质量安全风险评估实验室(合肥)安徽科立特农药环境评价科技有限公司

建立了同时测定小麦及其土壤中双氟磺草胺和氯氟吡氧乙酸残留的QuEChERS-超高效液相色谱-串联质谱方法,并采用该方法研究了低温冷藏条件下双氟磺草胺和氯氟吡氧乙酸在小麦上的储藏稳定性以及15%双氟磺草胺·氯氟吡氧乙酸悬乳剂在小麦和... 详细信息

建立了同时测定小麦及其土壤中双氟磺草胺和氯氟吡氧乙酸残留的QuEChERS-超高效液相色谱-串联质谱方法,并采用该方法研究了低温冷藏条件下双氟磺草胺和氯氟吡氧乙酸在小麦上的储藏稳定性以及15%双氟磺草胺·氯氟吡氧乙酸悬乳剂在小麦和土壤中的最终残留及消解动态。结果表明：在添加水平为0.005～1 mg/kg范围内,双氟磺草胺和氯氟吡氧乙酸在小麦及土壤中的平均回收率在82%～108%之间,相对标准偏差在0.41%～11%之间（n=5）,均能满足农药残留分析的要求。在–20℃下储藏365 d后,麦粒中双氟磺草胺和氯氟吡氧乙酸的残留量变化小于30%,符合植源性农产品中农药残留储藏稳定性试验准则要求,储藏稳定。双氟磺草胺在小麦植株和土壤中的消解半衰期分别为4.4～8.1 d和2.4～9.3 d;氯氟吡氧乙酸在小麦植株和土壤中的消解半衰期分别为7.9～10.6 d和11.8～24.8 d,即在相同的试验条件下双氟磺草胺在植株和土壤中消解速率快于氯氟吡氧乙酸的。采用推荐剂量有效成分180 g/hm^2和推荐高剂量有效成分270 g/hm^2的15%双氟磺草胺·氯氟吡氧乙酸悬乳剂于小麦田施药1次,在小麦收获期的麦粒中均未检出双氟磺草胺和氯氟吡氧乙酸残留。

关键词： QuEChERS 超高效液相色谱-串联质谱双氟磺草胺氯氟吡氧乙酸小麦土壤残留消解

扬子板块西南缘早前寒武纪地质演化:来自撮科元古宙变沉积岩碎屑锆石U-Pb年龄、Hf-O同位素的制约

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岩石学报 2025年第1期41卷 304-320页

作者：高嘉敏谢士稳刘倩王舫陶鹏龙涛中国地质大学(北京)地球科学与资源学院北京100083 中国地质科学院地质研究所北京离子探针中心北京100037 山东省第四地质矿产勘查院潍坊261021

扬子板块的太古宙-古元古代基底出露十分有限,制约了对扬子早前寒武纪地质演化的认识。本次研究对扬子板块西南缘撮科地区的大红山群和昆阳群变沉积岩开展了碎屑锆石原位U-Pb年龄、Hf-O同位素及微量元素研究。测年结果显示,大红山群谐... 详细信息

扬子板块的太古宙-古元古代基底出露十分有限,制约了对扬子早前寒武纪地质演化的认识。本次研究对扬子板块西南缘撮科地区的大红山群和昆阳群变沉积岩开展了碎屑锆石原位U-Pb年龄、Hf-O同位素及微量元素研究。测年结果显示,大红山群谐和锆石年龄分布于3092~1786Ma之间,最年轻碎屑锆石年龄为1786Ma,限定大红山群最大沉积时代为古元古代晚期。昆阳群谐和锆石年龄分布于2874~1031Ma之间,最年轻碎屑锆石年龄为1031Ma,表明昆阳群最大沉积时代为中元古代晚期。除少量较年轻锆石(<1.75Ga)外,昆阳群和大红山群具有相似的年龄分布特征,两个主要的年龄峰为2.0~1.85Ga和2.4~2.2Ga。尽管古元古代碎屑锆石的年龄峰与撮科地区已报道的古元古代岩浆活动期次一致,但仅有少部分碎屑锆石的Hf-O同位素特征与撮科古元古代岩浆岩相似,大多数碎屑锆石Hf-O同位素组成与加拿大Rae克拉通古元古代变沉积岩中碎屑锆石相似,暗示古元古代碎屑物质可能仅少部分来自撮科地区已识别的古元古代岩浆岩,而大部分可能来自与Rae克拉通发育的古元古岩浆岩相似的源区。大红山群和昆阳群中1.9~1.03Ga的碎屑锆石可能来自扬子西南缘发育的古元古代晚期-中元古代晚期岩浆岩。结合前人的资料,我们认为我国撮科和越南北部的Phan Si Pan带经历了与加拿大Rae克拉通相似的古元古代演化过程,支持2.4~2.3Ga扬子西南缘卷入Arrowsmith造山事件,并与Rae克拉通一起参与哥伦比亚超大陆聚合过程的认识。

关键词：扬子西南缘撮科地区哥伦比亚超大陆大红山群和昆阳群碎屑锆石