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International Journal of Minerals,metallurgy and materials 2022年第12期29卷 2152-2161页

作者： Yang You Jiabao Guo Gang Li Zhuang Zheng Yong Li Xuewei Lü College of materials Science and Engineering Chongqing UniversityChongqing 400044China chongqing key laboratory of vanadium–titanium metallurgy and New materials Chongqing UniversityChongqing 400044China

This work proposes a novel horizontal high-shear granulator for iron ore granulation before sintering *** granulation behavior such as growth process and structure of granules were firstly analyzed,followed by the effects of operation conditions such as water content,initial particle size distribution,and the concentrate *** results show that the granule size increased significantly with increasing the granulation time,and the structure of granule can be divided into three types:non-nuclei,single-nuclei,and *** promotes the coalescence and growth of particles,and a better granulation performance was obtained at the water content of 8.8wt%under the current raw material *** the nuclei particle ratio led to an increase in average size of granules and permeability of the granules bed,but a decrease in growth ***,with increasing of concentrate ratio,granulation performance such as granule size,bed permeability,and uniformity became worse.

关键词： horizontal high-shear granulation iron ore granule structure granulation performance size distribution

MoS_(2)/Co_(9)S_(8)/MoC heterostructure connected by carbon nanotubes as electrocatalyst for efficient hydrogen evolution reaction

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Journal of materials Science & Technology 2021年第20期79卷 29-34页

作者： Meng Wang Kailiang Jian Zepeng Lv Dong Li Gangqiang Fan Run Zhang Jie Dang College of materials Science and Engineering Chongqing UniversityChongqing400044China chongqing key laboratory of vanadium-titanium metallurgy and New materials Chongqing UniversityChongqing400044China

High-performance multifunctional materials for water splitting driven by low voltage are crucial for hydrogen evolution reaction(HER),but developing such materials is ***,a simple strategy was designed to build a MoS_(2)/Co_(9)S_(8)/MoC@CNT-N(MCM@CNT-N)heterostructure with a large number of *** the HER,the synthesized MCM@CNT-N heterostructure catalyst showed high efficiency and stable electrocatalytic performance,with a low overpotential of 174.2 mV and a small Tafel slope of 84.7 mV dec^(-1) at a current density of 10 mA cm^(-2) in 0.5 M H_(2)SO_(4).In addition to the function of heterojunctions,the excellent activity is also attributed to the introduction of Co and N atoms and the formation of carbon *** work provides a new approach to build efficient and low-cost electrocatalysts for electrochemical reactions.

关键词： MoS_(2) Heterostructure Hydrogen Electrocatalysis CNT

Solid-state reaction of a CaO−V_(2)O_(5)mixture:A fundamental study for the vanadium extraction process

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International Journal of Minerals,metallurgy and materials 2021年第9期28卷 1462-1468页

作者： Jun-yi Xiang Xin Wang Gui-shang Pei Qing-yun Huang Xue-wei Lv College of materials Science and Engineering Chongqing UniversityChongqing 400044China School of metallurgy and materials Engineering Chongqing University of Science and TechnologyChongqing 401331China chongqing key laboratory of vanadium-titanium metallurgy and advanced materials Chongqing UniversityChongqing 400044China

The aim of this study was to investigate the phase transformation and kinetics of the solid-state reaction of CaO−V_(2)O_(5),which is the predominant binary mixture involved in the vanadium recovery *** analysis,X-ray diffraction spectroscopy,scanning electron microscopy,and energy dispersive spectrometry were used to characterize the solid-state reaction of the *** extent of the solid reac-tion was derived using the preliminary quantitative phase analysis of the X-ray *** results indicate that the solid reaction of the CaO−V_(2)O_(5)mixture is strongly influenced by the reaction temperature and CaO/V_(2)O_(5)mole *** transformation of calcium vanadate in-volves a step-by-step reaction of CaO−V_(2)O_(5),CaO−CaV_(2)O_(6),and CaO−Ca_(2)V_(2)O7 depending on the CaO/V_(2)O_(5)mole *** kinetic data of the solid reaction of the CaO−V_(2)O_(5)(1:1)mixture followed a second-order reaction *** activation energy(Ea)and preexponential factor(A)were determined to be 145.38 kJ/mol,and 3.67×10^(8)min^(−1),respectively.

关键词： calcium vanadate vanadium extraction solid-state reaction kinetics

Reduction kinetics of MgO-doped calcium ferrites under CO-N2 atmosphere

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Journal of Iron and Steel Research International 2019年第12期26卷 1265-1272页

作者： Tian-xiong Wang Cheng-yi Ding Xue-wei Lv Sen-wei Xuan Gang Li chongqing key laboratory of vanadium-titanium metallurgy and New materials Chongqing UniversityChongqing 400044China School of materials Science and Engineering Chongqing UniversityChongqing 400044China

The effect of magnesia on calcium ferrite(***2O3)reduction by CO was examined by isothermal *** of calcium ferrite added with 0,2,4,and 8 wt.%magnesia(abbreviated as CF,CF2M,CF4M,and CF8M)were *** composition was analyzed by X-ray diffraction,and the results indicated that CF2M and CF4M are reduced to lower reduction degree and with lower apparent activation energy than CF;and CF8M with more ***2O3 is reduced to a lower degree and with more difficulty compared with *** rate analysis revealed that CF,CF2M,CF4M,and CF8M reductions are all typical two-step reactions with the order of CF→CWF(***2O3)→*** apparent reduction activation energies of CF,CF2M,CF4M,and CF8M are 46.89,37.30,17.30,and 29.20 kJ/mol,*** analysis depicted that CF2M,CF4M,and CF8M reductions are all described by 2D Avrami–Erofeev(A–E)equation(A2)in the whole process,while CF reduction is first expressed by A2 and then by 3D A–E equation(A3).Different from shrinking core model,a new kinetic model for powdery samples reduction was proposed to illustrate the relationship among reduction rates,reduction routes,and model functions.

关键词： Calcium ferrite Magnesia Reduction kinetics Reduction model

Wear resistance performance of high entropy alloy–ceramic coating composites synthesized via a novel combined process

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Chinese Journal of Chemical Engineering 2023年第5期57卷 202-213页

作者： Junyu Chen Yu Yang Yuzheng Pan Yang You Liwen Hu Meilong Hu College of materials Science and Engineering Chongqing UniversityChongqing 400044China chongqing key laboratory of vanadium-titanium metallurgy and New materials Chongqing UniversityChongqing 400044China

titanium nitride(TiN), characterized by its high hardness and strength, was widely used as ceramic coating to improve the wear resistance of matrix materials. In this work, AlCrFeNiTi_(x) high-entropy alloy(HEA) powders were synthesized by direct electrochemical reduction in molten salt from the mixed metal oxides. Then,TiN ceramic coating on the AlCrFeNiTi_x bulk HEA containing the topologically close-packed(TCP) phase(σphase, Laves phase, and Ti_(3)Al phase) was prepared by vacuum hot pressing sintering, where nitride element come from boron nitride parting agent sprayed on the graphite mold. The effect of titanium content on the crystal structure, microstructure, hardness, and wear resistance of the products were investigated by X-ray diffraction, field emission scanning electron microscope, field emission electron-probe microanalysis,Vickers hardness tester, and friction–abrasion testing machine. The bulk HEAs exhibit excellent hardness and its hardness increases significantly with the increase of titanium content. The wear mechanism changes from both of predominantly delamination and accompanied oxidative wear to single delamination wear,which is due to ultra-high melting point and high hot hardness of TiN, that can effectively prevent the oxidation and deformation of the worn surface. Formation of the ceramic coatings containing the TiN second phase and TCP phase are the key factor to AlCrFeNiTi_x alloy with the excellent hardness and wear properties.

关键词： High-entropy alloys Electrochemical reduction Vacuum hot pressing sintering Hardness Wear resistance

Irregular initial solidification by mold thermal monitoring in the continuous casting of steels:A review

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International Journal of Minerals,metallurgy and materials 2024年第5期31卷 1003-1015页

作者： Qiuping Li Guanghua Wen Fuhang Chen Ping Tang Zibing Hou Xinyun Mo College of materials Science and Engineering Chongqing UniversityChongqing 400044China chongqing key laboratory of vanadium-titanium metallurgy and New materials Chongqing UniversityChongqing 400044China

Occasional irregular initial solidification phenomena,including stickers,deep oscillation marks,depressions,and surface cracks of strand shells in continuous casting molds,are important limitations for developing the high-efficiency continuous casting of *** application of mold thermal monitoring(MTM) systems,which use thermocouples to detect and respond to temperature variations in molds,has become an effective method to address irregular initial solidification *** systems are widely applied in numerous steel companies for sticker breakout ***,monitoring the surface defects of strands remains ***,indepth research is necessary to utilize the potential advantages and comprehensive monitoring of MTM *** paper summarizes what is included in the irregular initial solidification phenomena and systematically reviews the current state of research on these phenomena by the MTM ***,the influences of mold slag behavior on monitoring these phenomena are ***,the remaining problems of the formation mechanisms and investigations of irregular initial solidification phenomena are discussed,and future research directions are proposed.

关键词： irregular initial solidification mold thermal monitoring continuous casting mold slag thermocouple

Microemulsion leaching of vanadium from sodium-roasted vanadium slag by fusion of leaching and extraction processes

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International Journal of Minerals,metallurgy and materials 2021年第6期28卷 974-980页

作者： Yun Guo Hong-yi Li Yi-heng Yuan Jie Huang Jiang Diao Gang Li Bing Xie College of materials Science and Engineering Chongqing UniversityChongqing 400044China chongqing key laboratory of vanadium-titanium metallurgy and New materials Chongqing UniversityChongqing 400044China

The fusion of the leaching and purification processes was realized by directly using microemulsion as the leaching *** bis-(2-ethyhexyl)phosphoric acid(DEHPA)/n-heptane/NaOH microemulsion system was established to directly leach vanadates from sodium-roasted vanadium *** effect of the leaching agent on the leaching efficiency was investigated,in addition to the molar ratio of H_(2)O/NaDEHP(W),DEHPA concentration,solid/liquid ratio,stirring time,and leaching *** optimal situations,the vanadium leaching efficiency reaches 79.57%.The X-ray diffraction characterization of the leaching residue and the Raman spectrum of the microemulsion before and after leaching demonstrate the successful entry of vanadates from the sodium-roasted vanadium slag into the *** proposed method successfully realizes the leaching and purification of vanadates in one step,thereby greatly reducing production costs and environmental *** also offers a new way to achieve the green recovery of valuable metals from solid resources.

关键词： vanadium slag sodium roasting clinker microemulsion leaching extraction

Effects of PbO poisoning on Ce-Mn/AC catalyst for low-temperature selective catalytic reduction of NO with NH_(3)

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Journal of Iron and Steel Research International 2021年第2期28卷 133-139页

作者： Zeng-hui Su Shan Ren Tian-shi Zhang Jie Yang Yu-han Zhou Lu Yao College of materials Science and Engineering Chongqing UniversityChongqing 400044China chongqing key laboratory of vanadium-titanium metallurgy and New materials Chongqing UniversityChongqing 400044China

As a common heavy metal in the sintering flue gas,Pb can exist in the form of oxide(PbO)and lead to the decrease in the denitration catalysts ***-Mn/AC(activated carbon)and PbO-Ce-Mn/AC catalysts were prepared by impregnation method and their selective catalytic reduction of NH_(3) with NO was *** showed that selective catalytic reduction activity of Ce-Mn/AC decreased remarkably after doping *** the NO conversion of Ce-Mn/AC reached 94.52% at 200℃,while the value was reduced to 65.8% after doping PbO at the same *** doping of PbO decreased the total pore volume and oxygen functional groups of activated carbon,increased crystallinity of Mn oxides on the catalyst,decreased Mn^(4+) and chemisorbed oxygen content and then inhibited the“fast selective catalytic reduction”denitration reaction for Ce-Mn/AC *** this basis,the poisoning effects of lead oxide on Ce-Mn/AC catalysts for low-temperature selective catalytic reduction were revealed.

关键词： Ce-Mn/AC catalyst PbO poisoning Fast selective catalytic reduction Poisoning effect

Study on the hydrogen absorption properties of a YGdTbDyHo rare-earth high-entropy alloy

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International Journal of Minerals,metallurgy and materials 2025年第1期32卷 127-135页

作者： Tongyue Li Ziliang Xie Wenjiao Zhou Huan Tong Dawen Yang Anjia Zhang Yuan Wu Xiping Song State key laboratory for advanced Metals and materials University of Science and Technology BeijingBeijing 100083China Whole Win(Beijing)materials Sci.&Tech.Co. Ltd.Beijing 100083China

This study investigated the microstructure and hydrogen absorption properties of a rare-earth high-entropy alloy(HEA),*** indicated that the YGdTbDyHo alloy had a microstructure of equiaxed grains,with the alloy elements distributed *** hydrogen absorption,the phase structure of the HEA changed from a solid solution with an hexagonal-close-packed(HCP)structure to a high-entropy hydride with an faced-centered-cubic(FCC)structure without any secondary phase *** alloy demonstrated a maximum hydrogen storage capacity of 2.33 H/M(hydrogen atom/metal atom)at 723 K,with an enthalpy change(ΔH)of-141.09 kJ·mol^(-1)and an entropy change(ΔS)of-119.14 J·mol^(-1)·K^(-1).The kinetic mechanism of hydrogen absorption was hydride nucleation and growth,with an apparent activation energy(E_(a))of 20.90 kJ·mol^(-1).Without any activation,the YGdTbDyHo alloy could absorb hydrogen quickly(180 s at 923 K)with nearly no incubation period *** reason for the obtained value of 2.33 H/M was that the hydrogen atoms occupied both tetrahedral and octahedral *** results demonstrate the potential application of HEAs as a high-capacity hydrogen storage material with a large H/M ratio,which can be used in the deuterium storage field.

关键词： rare-earth high-entropy alloy hydrogen absorption capacity pressure–composition–temperature curves kinetics

Numerical simulation of coupling multi-physical field in electrical arc furnace for smelting titanium slag

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Journal of Iron and Steel Research International 2023年第11期30卷 2194-2209页

作者： He-nan Cui Tao Li Chen-guang Bai Min Tan Yu-lin Zhu College of materials Science and Engineering Chongqing UniversityChongqing400044China chongqing key laboratory of vanadium-titanium metallurgy and advanced materials Chongqing UniversityChongqing400044China College of metallurgy and Energy North China University of Science and TechnologyTangshan063210HebeiChina

The smelting reduction process of the ilmenite in an electric arc furnace(EAF)is a commonly used technology for producing titanium slag in the *** has particular significance to analyze the velocity-temperature-electromagnetics multi-physical field in an EAF for improving its productivity and reducing energy consumption.A transient three-dimensional mathematical model was developed to characterize the flow,heat transfer,and electromagnetic behavior in a titanium slag *** describing the electromagnetic field and its effects on velocity and temperature distribution in the furnace,magnetohydrodynamic equations and conservation equations for mass,momentum,and energy were solved simultaneously by compiling the user-defined function *** numerical model was verified by comparing with the literature *** results indicate that the Lorentz force is the main driving force of the velocity and temperature ***,the influence of input current and location of electrodes on the multi-physical field distribution was also *** is found that the appropriate range of input current and diameter of pitch circle are about 30,000 A and 3000-3500 mm,*** mathematical model established can characterize the multi-physical field more accu-rately than before,which can provide valuable guidance for the operation improvement and design optimization of the EAF for producing titanium slag.

关键词： Electric arc furnace titanium slag Magnetohydrodynamic Multi-physical field User-defined function