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Initial stages of Nb_(3)Sn phase formation in Nb-bronze matrix co.posite wires investigated by means of electron microsco.y

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Rare Metals 2021年第3期40卷 708-713页

作者： Shu-Rui Li Bin Hu Hui-Jie Ren Lei Wang Xing-Ming Wang GRINM Resources and Environment Technology co. Ltd.Beijing 101407China GRINM group co. Ltd.Beijing 100088China CRRC Beijing ERQI Vehicle co. Ltd.Beijing 100072China

At present,Nb_(3) Sn superco.ductors are beco.ing more popular in high magnetic *** growth law of Nb_(3) Sn phase in a planar CuSn/Nb diffusion co.ple has been studied,whereas the formation mechanism of Nb_(3) Sn phase in a cylindrical CuSn/Nb diffusion co.ple is still *** purpose of this work is to investigate the growth exponent of Nb_(3) Sn phase at the initial stage of annealing by use of scanning electron microsco.y(SEM)through which the thickness of Nb_(3) Sn layer can be *** this study,bronze-processed Nb_(3) Sn multifilamentary wires with different annealing time were *** Nb_(3) Sn phase was formed during isothermal annealing at 670 ℃ by solid-state diffusion,which was acco.plished by the movement of Sn atoms from the CuSn/Nb_(3) Sn interface to Nb_(3) Sn/Nb ***,the formation mechanism of Nb_(3) Sn phase at the initial stage of annealing is still not well *** evolution of Nb_(3) Sn phase during isothermal annealing was studied by *** mean thickness of the Nb_(3) Sn layer(Δ(xNn3 Sn)) is expressed as a power function of the annealing time(t) by the equation A_(x^(2)Nb_(3) Sn)=k(t/t0)^(n),where t0 is the unit time,k is the reaction rate co.stant and n is the growth *** growth exponent has the average value of 0.82,which means that the formation of the Nb_(3) Sn phase is both governed by the interface reaction and the grain boundary diffusion.

关键词： Nb_(3)Sn phase Quantitative characterization Isothermal annealing Microstructural evolution Formation mechanism

Increasing leaching rate of gold cyanide of two-stage calcination generated from refractory ore co.taining arsenopyrite and pyrrhotite

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Rare Metals 2016年第10期35卷 804-810页

作者： Xiao-E Dang Wen-Shuai Ke Chen Tang Jun Lv Xue Zhou Cheng-Peng Liu Key Laboratory for gold and Resources of Shaanxi Xi'an University of Architecture and Technology Jin Rui mining Technology Development co. Ltd

For the gold locked within hematite in the two- stage calcination, which leads to a low gold leaching rate, the present work is aiming at pretreating the calcination to selectively dissolve hematite. The calcination was pre- treated by sulfuric acid with co.olvent B. The factors in- fluencing the hematite dissolution rate were studied, and the pretreatment parameters co.sidered were H2SO4 co.- tent, B dosage and added time, leaching temperature and time. Simultaneously, mineralogy analysis of the calcination, H2SO4 pretreatment residue and cyanide leaching residue were also carried out. Results indicate that the hematite dissolution rate is quicker, the dissolution tem- perature is lower and the dissolution time is shorter in the role of co.olvent B than without B. At the same time, the gold locked within hematite is effectively released, so the leaching rate of gold cyanide increases about 10 % than that in actual factory production. The results have an actual significance in guiding industrial production.

关键词： Locked gold Hematite Pretreatment Two-stage calcination co.olvent B

Characteristics and mechanisms of strain waves generated in rock by cylindrical explosive charges

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Journal of Central South University 2016年第11期23卷 2951-2957页

作者：刘科伟李萧翰李夕兵姚志华舒宗宪袁明华 School of Resources and Safety Engineering Central South University Yuxi mining co. ltd. Yunnan Copper Industry (Group) Hunan Key Laboratory of Resources Exploitation and Hazard co.trol for Deep Metal Mines Central South University

A superposing principle, by suitably adding the strain waves from a number of co.centrated explosive charges to approximate the waves generated by a cylindrical charge based on the strain wave of a point or small spherical explosive charge generated in rock, is used to further study the triggering time of strain gauges installed in radial direction at same distances but different positions surrounding a cylindrical explosive charge in rock. The duration of the first co.pression phase and peak value of strain wave, and furthermore, their differences are analyzed and some explanations are given. Besides that, the gauge orientation in which the maximum peak value occurs is also discussed. At last, the effect of velocity of detonation(V.O.D.) of a cylindrical explosive charge on the strain waves generated in the surrounding rock is taken as key research and the pattern of peak amplitude of a strain wave varies with the V.O.D. is likely to have been found.

关键词： cylindrical explosive charge strain wave co.centrated explosive charge elemental strain wave superposing principle velocity of detonation(V O D ) velocity of propagation(V O P )

High-resistance co.trolled yielding supporting technique in deep-well oil shale roadways

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International Journal of mining Science and Technology 2014年第2期24卷 229-236页

作者： Yu Yang Bai Jianbiao Wang Xiangyu Wang Junde Xue Shizhi Xu Ke School of mining Engineering Stata Key Laboratory of Coal Resources and Safety MiningChina University of Mining & Technology Haishiwan co.l Mine Yaojie Coal Electricity Group Co.Ltd. Tai’an Ark Mine Science and Technology co. Ltd.

In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and supporting in Haishiwan co.l mine, this paper has analyzed the characteristics of the deformed roadway and revealed its failure mechanism by taking co.prehensively the methods of field geological investigation, displacement monitoring of surrounding rock, rock properties and hydration properties experiments and field application tests. Based on this work, the high-resistance co.trolled yielding supporting principle is proposed, which is： to ＂resist＂ by high pre-tightening force and high stiff- ness in the early stage, to ＂yield＂ by making use of the co.trolled deformation of a yielding tube in the middle stage, and to ＂fix＂ by applying total-section Gunite in the later stage. A high-resistance co.trolled yielding supporting technique of ＂high pre-tightening force yielding anchor bolt ＋ small-bore pre-tight- ening force anchor cable ＋ rebar ladder beam ＋ rhombic metal mesh ＋ lagging gunite＂ has been estab- lished, and industrial on site testing implemented. The practical results show that the high-resistance co.trolled yielding supporting technique can effectively co.trol the large deformation and long-time rheology of deep-well oil shale roadways and can provide beneficial references for the maintenance of other co.-generic ***-well Oil shale

关键词： Deformation failure mechanism High-resistance co.trolled yielding supporting Yielding anchor bolt

Effects of ferrosilico. alloy,Si co.tent of steel,and slag basicity on co.positions of inclusions during ladle furnace refining of Al-killed steel

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Journal of Iron and Steel Research International 2020年第9期27卷 1011-1017页

作者： Jian-fei Xu Kun-peng Wang Ying Wang Zhi-dong Qu Xing-kuang Tu Zenith Steel group co. Ltd.Changzhou 213000JiangsuChina

To obtain solid Al2O3 or MgO·Al2O3 inclusions in ladle furnace(LF)refining process and achieve ultra-low total oxygen co.tent in steel through subsequent Ruhrstahl Heraeus degassing,the effects of ferrosilico. alloy,Si co.tent of steel,and slag basicity on the co.positions of inclusions during LF refining were investigated in Al-killed ***2O3 inclusions co.ld be transformed into CaO-Al2O3-MgO-CaS inclusions after adding ferrosilico. alloy in the LF refining process as this alloy co.tains some CaSi alloy *** addition of all ferrosilico. alloys required for the steel in the tapping process co.ld eliminate the influence of Ca in ferrosilico. alloy on the co.positions of *** in liquid steel had a significant influence on the co.positions of inclusions during LF refining when CaO-Al2O3-SiO2-MgO slag with high basicity of 7.0 was *** was because[Ca]produced by the reaction of CaO and[Al]co.ld be co.sumed more readily by SiO2 in Si-free steel than in Si-co.taining steel,which was co.firmed by the difference of total calcium co.tent between Si-free and Si-co.taining *** a result,Al2O3 and MgO·Al2O3 inclusions were retained in Si-free steel,whereas calcium aluminate inclusions were found in Si-co.taining *** CaO-Al2O3-SiO2-MgO slag with low basicity of 2.8,Al2O3 and MgO·Al2O3 inclusions were obtained after LF refining in Si-co.taining steel when all ferrosilico. alloys required for the steel were added in the tapping *** was because the reaction of CaO and[Al]was weak,and residual[Ca]in the steel co.ld be rapidly co.sumed by SiO2 in low-basicity slag owing to the low activity of CaO and high activity of SiO2,leading to a low total calcium co.tent of 0.0003%in Si-co.taining steel.

关键词： Inclusion Ferrosilico. alloy Si co.tent Basicity LF refining

Lithium co.altate:a novel host material enables high-rate and stable lithium-sulfur batteries

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Rare Metals 2018年第11期37卷 929-935页

作者： Wen Ma Qing Xu GRINM Bohan (Beijing) Publisher co. Ltd.GRINM Group Co.Ltd. Subinstitute of Standardization Theory and Strategy China National Institute of Standardization

Element sulfur is highly attractive due to their potentially low co.t and environmental ***, polysulfides dissolution hinders the lithiumsulfur(Li-S) batteries toward co.mercialization. To overco.e these issues, in this work, lithium co.altate as a co.mercial material, for the first time, was devoted to engineering the electrode structure and co.position to improve the performance. When inco.porated with 80% sulfur powder, the synergetic effects of co.alt atoms and interlayer spaces effectively enable the production of Li-S batteries with a relatively high discharge capacity of 1420 mAh·g-1at the low surface current density of 1 mA·cm-2and stable capacity retention of 650 mAh·g-1at high surface current density of 6 mA·cm-2. The introduction of lithium co.altate is a viable approach for successfully developing practical Li-S batteries.

关键词： Lithium co.altate Polysulfides dissolution Electrochemical properties Lithium-sulfur batteries

Role of ammonium sulfate in sulfurization flotation of azurite:Inhibiting the formation of co.per sulfide co.loid and its mechanism

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International Journal of mining Science and Technology 2022年第3期32卷 575-584页

作者： Jinpeng Cai Chao Su Yinyu Ma Xingcai Yu Rong Peng Jiangli Li Xiaolin Zhang Jianjun Fang Peilun Shen Dianwen Liu State Key Laboratory of co.plex Nonferrous Metal Resources Clean Utilization Yunnan Key Laboratory of Green Separation and Enrichment of Strategic Metal ResourcesFaculty of Land Resources EngineeringKunming University of Science and TechnologyKunming 650093China Shandong gold group co. LtdJinan 250014China yunnan Posphate group co. LtdKunming 650600China

In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were *** flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased the formation of co.loid in flotation pulp,and the floatability of the suppressed azurite caused by excess sodium sulfide was *** adding(NH_(4))_(2)SO_(4)prior to sulfurization,the formation of Cu(NH_(3))_(n) ^(2+)intermediate products changed the path of the sulfurization reaction,which slowed the direct impact of HSon the azurite *** nucleation rate was reduced,and the growth of co.per sulfide crystal was ***(syn,CuS)with larger crystal grains was formed on the azurite surface,thereby enhancing the mechanical stability of co.per sulfide products onto the mineral ***,the generated co.per sulfide co.loid significantly reduced,ultimately promoting the effective adsorption of xanthate on the azurite surface.

关键词： Azurite Sulfurization flotation Ammonium sulfate co.loid Inhibition Crystal growth

Design and fabrication of a low modulus β-type Ti-Nb-Zr alloy by co.trolling martensitic transformation

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Rare Metals 2018年第9期37卷 789-794页

作者： Qing-Kun Meng Yu-Fei Huo Wen Ma Yan-Wei Sui Jin-Yong Zhang Shun Guo Xin-Qing Zhao School of Materials Science and Engineering China University of Mining and Technology GRINM Bohan (Beijing) Publisher co. Ltd.GRINM Group Co.Ltd. School of Materials Science and Engineering Jiangsu University School of Materials Science and Engineering Beihang University

In this paper, high density of dislocations, grain boundaries and nanometer-scale α precipitates were intro- duced to a metastable Ti-36Nb-5Zr alloy （wt%） through a thermo-mechanical approach including severe co.d rolling and short-time annealing treatment. The martensitic trans- formation was retarded, and the β phase with low co.tent of β stabilizers was retained at room temperature after the thermo-mechanical treatment. As a result, both low mod- ulus （57 GPa） and high strength （950 MPa） are obtained. The results indicate that it is a feasible strategy to co.trol martensitic transformation start temperature through microstructure optimization instead of co.position design, with the aim of fabricating low modulus β-type Ti alloy.

关键词： Biomedical Ti alloys Martensitictransformation Low modulus Short-time annealing

A co.parison between DCCAE and co.ventional extrusion of Mg-9.5Li-3Al-1.6Y alloy

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Journal of Rare Earths 2016年第6期34卷 626-631页

作者：刘军威彭晓东王宝魏国兵谢卫东杨艳刘明朴 co.lege of Materials Science and Engineering Chongqing University National Engineering Research Center for Magnesium Alloys Zhengzhou co.l mining Machinery group co. ltd.

Double change channel angular extrusion（DCCAE） was performed in dual-phase Mg-9.5Li-3Al-1.6Y（wt.%） alloy to develop fine-grained microstructures. The microstructure evolution during DCCAE and co.ventional extrusion（CE） was investigated. The microstructure of the extruded dual-phase Mg-Li alloy co.sisted of recrystallized β-Li grains, banded α-Mg phases, and Al_2Y phases distributed in β-Li phases and phase-interface uniformly. co.pared with CE, the specimens after DCCAE had smaller β-Li grain size（3–5 μm by the DCCAE and 6–10 μm by the CE） and the α-Mg phases were refined during the DCCAE. The distribution of the Al2 Y phases was improved a lot by DCCAE. Furthermore, the specimens after DCCAE had better tensile strength than co.ventional extrusion ones.

关键词： DCCAE dual-phase Mg-Li alloy Al_2Y fine-grained rare earths