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Rare Metals 2024年第3期43卷 1275-1287页

作者： Shao-Le Song Run-Qing Liu Miao-Miao Sun Ai-Gang Zhen Fan-Zhen Kong Yue Yang School of Minerals Processing and Bioengineering Central South UniversityChangsha410083China Zhejiang Tianneng new materials co. Ltd.Huzhou313103China

The recycling of cathode materials from spent lithium-ion battery has attracted extensive attention,but few research have focused on spent blended cathode materials.In reality,the blended materials of lithium iron phosphate and ternary are widely used in electric vehicles,so it is critical to design an effective recycling technique.In this study,an efficient method for reco.ering Li and Fe from the blended cathode materials of spent LiFePO_(4)and LiNi_(x)co.(y)Mn_(1-x-y)O_(2)batteries is proposed.First,87%A1 was removed by alkali leaching.Then,91.65%Li,72.08%Ni,64.6%co.and 71.66%Mn were further separated by selective leaching with H_(2)SO_(4)and H_(2)O_(2).Li,Ni,co.and Mn in solution were reco.ered in the form of Li_(2)co.(3)and hydroxide respectively.Subsequently,98.38%Fe was leached from the residue by two stage process,and it is reco.ered as FePO_(4)·2H_(2)O with a purity of 99.5%by precipitation.Fe and P were present in FePO_(4)·2H_(2)O in amounts of 28.34%and 15.98%,respectively.Additionally,the drift and co.trol of various co.ponents were discussed,and co.t-benefit analysis was used to assess the feasibility of potential application.

关键词： Spent lithium-ion battery Blended cathode materials Reco.ery Lithium carbonate Iron phosphate

The Formation of SO_(2) and Emission Reduction Solutions in the Preparation of a Hydrogenation catalyst Support

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China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 98-106页

作者： Hu Anpeng Wang Zhen Yang Qinghe Hu Dawei Gong Yu Jia Yanzi Dai Qiaoling Pu Ning SINOPEC Research Institute of Petroleum Processing Beijing 100083China Zibo Qimao catalyst co. Ltd.Zibo 255400China

The key reason for SO_(2) formation during the production of a residue hydrogenation catalyst support was identified and subsequent emission reduction solutions were then investigated and verified systematically.The results demonstrated that carbon-co.taining organic materials,including sesbania powder and cellulose,did not co.pletely deco.pose over the temperature range of 350−600℃during the heating stage of the calcination process,but rather underwent a co.densation reaction within the same temperature range to form carbon-co.taining species with a lower ratio of hydrogen to carbon and a higher co.densation degree,which promoted the deco.position of sulfate to form SO_(2).Systematic experimental work revealed that three different measures,i.e.,applying the staged calcination method,reducing the heating rate,and increasing the air flow rate,during the calcination process co.ld all achieve the effect of reducing SO_(2) emissions.

关键词： alumina sesbania powder cellulose sulfur dioxide

Effect of neodymium doping on structure,magnetic properties and microwave absorption performance of SrMnO_(3)

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Journal of Rare Earths 2024年第2期42卷 354-363,I0005页

作者： Jixiang Yue Lichun Cheng Jilei Xiong Qingrong Yao Man Wang Yucheng Chen Qianxin Long Xiaojian Guo School of materials Science and Engineering Guilin University of Electronic TechnologyGuilin541004China Guangxi Key Laboratoryof Information materials Guilin University of Electronic Technology Guilin541004China Anhui Jihua new materials co. Ltd.Anqing246300China

A simple co.posite Sr_(1-x)Nd_(x)MnO_(3)(x=0,0.05,0.1,0.15,0.2) nano powders were successfully prepared by the sol-gel method as a light-weight broadband electromagnetic wave absorber.The effect of Nd^(3+)doping on the structure,microstructure and properties of SrMnO_(3) was investigated.It is found that with the doping of Nd^(3+),the space group of the SrMnO_(3) changes from p63/mmc to pm3m,and the crystalline shape starts to change from hexagonal to cubic crystalline.Scanning electron microsco.y(SEM) and Brunauer-Emmett-Teller(BET) tests co.firm that the particle sizes of the sample decrease and the specific surface area increases,which are attributed to the inhibition of grain growth after Nd^(3+)is doped.X-ray photoelectron spectrosco.y(XPS) shows that after Nd^(3+)doping,the co.tent of oxygen vacancy increases,and Mn^(4+) co.verts to Mn^(3+).Due to the defects of the materials,the polarization effect is enhanced,thus,the dielectric and magnetic properties of the doped samples are improved.The maximum reflection loss of the Sr_(0.85)Nd_(0.15)MnO_(3) is-33.41 dB at 7.84 GHz for a thickness of 2.4 mm,while Sr_(0.9)Nd_(0.1)MnO_(3) has the best bandwidth performance at 2.32 GHz with a reflection loss below-10dB.

关键词： Sr_(1-x)Mn_xO_(3) Crystal structure Microwave absorption Magnetic properties Nano powder Rare earths

High cerium co.tent(Nd-Pr-Ce)_(2)Fe_(14)B melt-spun ribbons with high co.rcivity

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Journal of Rare Earths 2024年第4期42卷 690-695页

作者： Yujiang Zhong Junming Wang Zikai Yuan Ruijin Liu Minggang Zhu Zhe Liu Xin Chen Wei Li Zhaohui Guo Division of Functional materials Central Iron and Steel Research InstituteBeijing100081China Ningbo Jinji Strong Magnetic Material co. Ltd.Ningbo315172China Jiangxi Jiangwu Rare Metal new Material co. Ltd.Nanchang330013China

The effects of wheel speeds on the magnetic properties and microstructures of[(Nd,Pr)_(1-x)Ce_(x)]-Fe-B meltspun ribbons were investigated.co.pared to melt-spun ribbons with low cerium(Ce)co.tent(x=0.2),amorphous formation can be suppressed at high wheel speed in the ribbons with a relatively high Ce co.tent(x=0.8),and with the increase of the wheel speed,the magnetic properties of the ribbons with high Ce co.tent raise co.tinuously.At high wheel speed,the co.rcivity mechanism of melt-spun ribbons is mainly pinning field,and the high wheel speed introduces a large number of defects into the matrix as pinning sites.Furthermore,ribbons with high Ce co.tent form a fine and uniform grain structure,so the grain boundary area enlarges,which further hinders the movement of domain walls.The co.bined effects of the above factors enable ribbons with high Ce co.tent to have excellent magnetic properties(Hcj=0.977 T,Mr=64 m^(2) A/kg)at the wheel speed of 35 m/s.

关键词： Wheel speed Ceco.tent Microstructure Magnetic properties Rare earths

Occurrence and vertical distribution of aluminum and rare earths in weathered crust elution-deposited rare earth ore:Effect of soil solution pH and clay minerals

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Journal of Rare Earths 2024年第7期42卷 1394-1402页

作者： Jiaxin Pan Longsheng Zhao Zheng Li Xiaowei Huang Zongyu Feng Jun Chen National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd. School of Metallurgical and Eco.ogical Engineering University of Science and Technology Beijing (USTB) GRIREM Advanced materials co. Ltd. GRIREM Hi-Tech co. Ltd. GRIMAT Engineering Institute co. Ltd.

Weathered crust elution-deposited rare earth ore is crucial source of medium and heavy rare earths,with in-situ leaching being the most co.mon mining method.The high co.tents of impurity of aluminum in the leach solution are a significant challenge for the subsequent enrichment process of rare earths.A co.prehensive understanding of the occurrences and vertical distribution of aluminum and rare earths within typical vertical profiles can provide valuable insights into entire design of the in-situ leaching.This paper improves a five-step sequential extraction method to analyze the occurrence and vertical distribution of rare earths and aluminum in vertical profiles from Chongzuo and Longyan.Experimental results demonstrate that soil solution pH is the main factor affecting the vertical distribution of ionexchangeable rare earths.Both samples have distinct areas of enrichment for ion-exchangeable rare earths or aluminum.Ion-exchangeable rare earths are primary co.centrated in the middle and lower parts of the ore layer(4-13 m in Chongzuo,14-22 m in Longyan),while the ion-exchangeable aluminum is mainly enriched in the upper part of the ore layer(1-5 m in Chongzuo,and 2-14 m in Longyan).The vertical distribution of inorganic hydroxy aluminum is likely influenced by the micro morphology and particle size of the day minerals.The inorganic hydroxy aluminum co.centration in Chongzuo samples decreases co.tinuously from 415.65 to 120.95 mg/kg with increasing sampling depth,whereas the co.centration in Longyan samples(110.55-171.27 mg/kg) is almost independence with sampling depth.These results provide direct guidance for the entire design of the injection well depth and the leaching parameters,thereby inhibiting the leaching of impurity of aluminum and lower the co.sumption of leaching agent.

关键词： Aluminum Occurrence Rare earth elements Sequential extraction Weathered crust elution-deposited rare earth ore

Solidification behaviour and hot cracking susceptibility of a novel Ni-based superalloy

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Journal of Iron and Steel Research(International) 2024年第4期31卷 956-966页

作者： Yue Chen Shao-min Lv Xing-fei Xie Xiao-can Wen Jng-long Qu Jin-hui Du High-Temperature materials Institute China Iron and Steel Research Institute Group Co.Ltd.Beijing 100081China Beijing GAONA materials and Technology co. Ltd.Beijing 100081China Sichuan CISRI-GAONA Forging co. Ltd.Deyang 610000SichuanChina

A novel Ni-based superalloy GH4151,with a γ′ volume fraction of about 55%and a service temperature capability up to 8oo oC,was investigated.Due to the different co.ling co.ditions of various regions during the solidification of ingots,significant co.ling rate variations may lead to the occurrence of hot cracking.co.ventional scanning laser microsco.e was utilised to investigate the solidification process and phase precipitation behaviour of the GH4151 under wide range co.ling rates.The characteristics of L→γ transformation were analysed,and the growth rates of at each stage were calculated.The segregation behaviour was predicted using the Scheil equation,and the predicted results match well with the experimental results.The sensitivity co.fficient for hot cracking was modified,and cracking sensitivity co.fficient values for the alloy under different co.ling rates were co.puted,revealing that the alloy is most susceptible to hot cracking at 10℃/min co.ling rate.Therefore,co.trolling the co.ling rate can reduce the possibility of hot cracking in ingot.

关键词： Ni-based superalloy Solidification behaviour In-situ observation Clyne and Davies's criterion:Hot cracking susceptibility

Tungsten separation behavior on preparation of high-purity cerium by co.bined vacuum gravity sedimentation-directional solidification

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Journal of Rare Earths 2024年第6期42卷 1182-1186,I0007页

作者： Dongwei Zhang Wenli Lu Minglei Xu Dehong Chen Xiaowei Zhang Chuang Yu Wensheng Yang Ruifeng Dong Zhiqiang Wang Liguo Han Zengdong Pang GRIREM Hi-Tech co. Ltd.Langfang065201China National Engineering Research Center for Rare Earth China GRINM Group Co.Ltd.Beijing100088China GRIREM Advanced materials co. Ltd.Beijing100088China

In light of the difficult removal of harmful impurity tungsten(W)in Ce metal,in this paper a co.bined vacuum gravity sedimentation-directional solidification method was innovatively designed and the W separation behavior was investigated.By reducing the electron beam power instantly and gradually at reduction rates of 1,3 and 5 kW/min,it is found that W is enriched at the bottom of ingots as the melt solidifies.The enrichment effect is much better than that of single purification method and the enrichment degree increases as the beam reduction rate decreases,attributed to the k0(W)>1 andρ(W)>ρ(Ce).Overall,the minimum co.tent of W impurity can decrease from 630 to 0.1 ppm at the top of the ingot,and the purity of Ce increases from 99.932 wt%to 99.995 wt%by this co.bined method.Additionally,this paper provides a new method for the removal of high density and low evaporation co.fficient impurities in low vapor pressure rare earth metals.

关键词： Cerium Electron beam melting Directional solidification Gravity sedimentation Rare earths

Surface deco.ation of mesocarbon microbeads with multifunctional TiNbO4-x@C co.ting layer as high rate and stable anode of Li-ion batteries

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Rare Metals 2024年第5期43卷 2053-2066页

作者： Jia-Mei Lai Zhi-Min Zou Yu Bai Yu-Tao Xing Chun-Hai Jiang Fujian Provincial Key Laboratory of Functional materials and Applications Institute of Advanced Energy Materials School of Materials Science and Engineering Xiamen University of Technology Shanghai XFH Science and Technology Development co. Ltd. Fujian XFH new Energy materials co. Ltd. Shenzhen XFH Science and Technology co. Ltd. Laboratório de Microsco.ia Eletr?nica de Alta Resolu??o Centro de Caracteriza??o Avan?ada Para a Indústria de Petróleo (LaMAR/CAIPE) Universidade Federal Fluminense

Surface modification of graphite anode with electroactive matters has been proven of a more practical strategy in enhancing the performance of Li-ion batteries than exploring alternative novel anode materials.Herein,rutile Ti NbO4-xnanoparticles with a tunnel structure are employed as multifunctional deco.ation substances in co.bination with a carbon co.ting layer to improve the rate and cycle properties of mesocarbon microbeads（MCMBs）.As co.pared to pristine MCMB,the Li+diffusion co.fficients of the co.posite anodes are enhanced due to the synergistic effect of Ti Nb O4-x@C.Meanwhile,the overcharge and voltage polarization of the co.posite anodes at high rate are obviously minimized due to the current sharing effect of the high-potential TiN-bO4-x.Moreover,the amorphous LiyTi Nb O4-xco.verted from Ti NbO4-xin the initial lithiation process can deliver pseudocapacitive capacity to the co.posite anodes from the seco.d cycle.All of these functions of Ti NbO4-x@C co.ting layer have directly co.tributed to the improved rate and cycle performance of the MCMB/TiNbO4-x@C co.posite anodes.The one co.taining 12.0 wt%Ti NbO4-xexhibits a high reversible specific capacity of 118 m Ah·g-1at 10C (1C=372 m A·g-1),together with a high capacity retention of 90.9%after 300 cycles at 3C,which are all much superior to those of pristine MCMB.

关键词： Li-ion batteries MCMB TiNbO 4− x Surface deco.ation Rate capability

Mechanism of a dual-phase Ti-Nb alloy exhibiting near-linear elastic deformation

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Rare Metals 2024年第5期43卷 2282-2289页

作者： Yan Guo Wang Ding Wen Ma Shun Guo Hao-Dong Meng Nian-Yao Xu School of Automotive Engineering Changzhou Institute of Technology School of materials Science and Engineering Jiangsu University Youke Publishing co. Ltd China Grinm Group Co. Ltd

In this work, the underlying mechanism responsible for the near-linear elastic deformation behavior of a dual-phase Ti-Nb alloy co.sisting of β and a''phase with large reco.erable strain was systematically elucidated.Based on in situ synchrotron X-ray diffraction(SXRD)analyses, it was found that besides intrinsic elastic deformation, a slight reversible β ? a''stress-induced martensitic(SIM) transformation, which proceeded in a co.secutive mode under the retarding effect of micro-defects, took place during the near-linear elastic deformation.After unloading, a small amount of residual macrosco.ic strain remained in the specimen due to the inco.plete reverse a''→ β transformation on unloading. The high near-linear elastic deformability of the co.d drawing(CD)Ti-Nb alloy has been revealed to be attributed to the co.pling actions of intrinsic elasticity as well as the co.secutive and reversible β ? a''SIM transformation. Our research may co.tribute to a new avenue for the design and development of novel dual-phase Ti-based alloys with desirable elastic deformability.

关键词： Titanium alloys Dual-phase Near-linear elastic deformation Martensitic transformation

Long-Term Performance and Microstructural Characterization of Dam co.crete in the Three Gorges Project

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Engineering 2024年第2期33卷 237-262页

作者： Chen Lyu Cheng Yu Chao Lu Li Pan Wenwei Li Jiaping Liu School of materials Science and Engineering Southeast UniversityNanjing 211189China State Key Laboratory of High Performance Civil Engineering materials Sobute New Materials Co.Ltd.Nanjing 211103China China Three Gorges co.poration Wuhan 430010China

This study investigates the long-term performance of laboratory dam co.crete in different curing environments over ten years and the microstructure of 17-year-old laboratory co.crete and actual co.crete co.es drilled from the Three Gorges Dam.The mechanical properties of the laboratory dam co.crete,whether cured in natural or standard environments,co.tinued to improve over time.Furthermore,the laboratory dam co.crete exhibited good resistance to diffusion and a refined microstructure after 17 years.However,curing and long-term exposure to the local natural environment reduced the frost resistance.Microstructural analyses of the laboratory co.crete samples demonstrated that moderate-heat cement and fine fly ash(FA)particles were almost fully hydrated to form co.pact micro structures co.sisting of large quantities of homogeneous calcium(alumino)silicate hydrate(C-(A)-S-H)gels and a few crystals.No obvious interfacial transition zones were observed in the microstructure owing to the longterm pozzolanic reaction.This dense and homogenous microstructure was the crucial reason for the excellent long-term performance of the dam co.crete.A high FA volume also played a significant role in the microstructural densification and performance growth of dam co.crete at a later age.The co.crete drilled from the dam surface exhibited a loose microstructure with higher microporosity,indicating that co.crete directly exposed to the actual service environment suffered degradation caused by water and wind attacks.In this study,both macro-performance and microstructural analyses revealed that the application of moderate-heat cement and FA resulted in a dense and homogenous microstructure,which ensured the excellent long-term performance of co.crete from the Three Gorges Dam after 17 years.Long-term exposure to an actual service environment may lead to microstructural degradation of the co.crete surface.Therefore,the retained long-term dam co.crete samples need to be further researched to better understand its microstructural evolution

关键词： Three Gorges Dam Long-term performance Microstructural analysis Moderate-heat cement Fly ash