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4582篇 您的检索式:期刊名="Rare Metals"
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1Technology development for rare earth cleaner hydrometallurgy in China显示文摘China is the global leader in rare earth(RE)production using hydrometallurgical processes. Advantageous extraction techniques of rare earths from Baotou mixed rare earth minerals, bastnaesite, and ion-adsorption clays of rare earth deposits have been developed in China.The separation and purification technologies have also achieved rapid development. The industrial application processes for rare earth hydrometallurgy were summarized in the present paper. With the large demands and rapid development of rare earths, the issues of resources and environment are more prominent. This review gives an overview of the main processes that were developed in the past toward greener hydrometallurgy of rare earths in China. Based on the development of the rare earth industry,comprehensive utilization and cleaner production should still be focused on in the future, to support the sustainable development.Xiao-Wei Huang Zhi-Qi Long Liang-Shi Wang Zong-Yu Feng 2015Rare Metals2015,34,4:76
2Photocatalytic properties of BiOX (X = Cl, Br, and Ⅰ)显示文摘A novel series of photocatalysts,bismuth oxyhalide(BiOX,X =Cl,Br,and I),were synthesized by a hydrolysis method.The powder sam- pies were characterized by the use of X-ray diffraction(XRD),scanning electron microscope,and UV-Vis spectrophotometer.The XRD pattern showed that all the BiOX were well crystallized in the tetragonal structure.The band gaps of the sheet-shaped compounds BiOX(X= Cl,Br,and I)were 3.44,2.76,and 1.85 eV,respectively.BiOBr showed the highest photocatalytic activity in degrading rhodamine B(RhB) and evolving O_2 for its proper valence band(VB).BiOI has no photocatalytic activity.BiOCl showed the highest activity in decomposing isopropanol because of electron-hole pair separation through trapping electrons by oxygen vacancies.AN Huizhong DU Yi WANG Tianmin WANG Cong HAO Weichang ZHANG Junying 2008Rare Metals2008,27,3:43
3Short communication Catalytic synthesis of butyric esters with TiSiW_(12)O_(40)/TiO_2显示文摘The catalytic activities of TiSiW12O40/TiO2 in synthesizing ethyl ester, propyl ester, n-butyl ester, and amyl esterwere reported. It was demonstrated that TiSiW12O40/TiO2is an excellent catalyst. Various factors concemed with esterifica-tion were investigated. The optimum conditions were found: the mole ratio of alcohol to acid is 1.3:1, the mass ratio ofcatalyst to reactants is 1.5%, and the reaction time is 1.0 h. Under the optimum conditions, the yields are 88.0% for ethylester, 94.5% for propyl ester, 98.6% for n-butyl ester, 99.1% for n-amyl ester, and 96.7% for iso-amyl ester, respectively.YANGShuijin CHENLuchun SUNJutang 2003Rare Metals2003,22,1:46
4Rare earth ion modified TiO_2 sols for photocatalysis application under visible light excitation显示文摘TiO2 sols modified by rare earth (RE) ions (Ce4+, Eu3+, or Nd3+) were prepared by coprecipitation-peptization method. The photocatalysis activity was studied by investigating the photodegradation effects of active brilliant red dye X-3B. It is found that TiO2 sols modified by Ce4+, Eu3+, or Nd3+ have the anatase crystalline structure, which are prepared at 70°C. All REn+-TiO2 sol samples have uniform nanoparticles with similar morphology, which are homogenously distributed in aqueous colloidal systems. The particle sizes are 10, 8, and 12 nm for Nd3+-TiO2, Eu3+-TiO2, and Ce4+-TiO2, respectively.The character of ultrafine and positive charge sol particles contributes to the good adsorption of X-3B dye molecule on the surface of titania (about 30% X-3B adsorption amount). Experimental results exhibit that REn+-TiO2 sol photocatalysts have the capability to photodegrade X-3B under visible light irradiation. Nd3+-TiO2 and Eu3+-TiO2 show higher photocatalytic activity than Cea+-TiO2, which is due to the difference of standard redox potential of REn+/RE(n-1)+. REn+-TiO2 sols demonstrate more excellent interfacial adsorption and photodegradation effects to X-3B than P25 TiO2 crystallites. Moreover, the degradation mechanism of X-3B is proposed as dye photosensitization and electron scavenging by rare earth ions.XIEYibing YUANChunwei 2004Rare Metals2004,23,1:39
5Microstructure and mechanical properties of hypereutectic Al-Si alloy modified with Cu-P显示文摘The microstructure and mechanical properties of Al-14.6Si castings modified by Cu-P master alloy under different conditions were studied with optical microscope(OM) and mechanical testing and simulation(MTS).The results indicate that the Cu-P master alloy possesses not only obvious modification effect,but also longevity effect with more than 8 h on the hypereutectic Al-Si alloy.It is shown from thermal calculation,scanning electron microscope(SEM),and energy dispersive analysis of X-rays(EDAX) that the modification mechanism of Cu-P on primary silicon in the castings is heterogeneous nucleation around AlP particles.The Cu-P master alloy has no or little modifying effect on eutectic silicon,even though it has obvious modification on primary silicon in the castings.This may be because of the fast transformation of eutectic silicon at a very narrow temperature,which will notably weaken the role of AlP particles as heterogeneous nuclei for eutectic silicon.ZHANG Henghua DUAN Haili SHAO Guangjie XU Luoping 2008Rare Metals2008,27,1:35
6Effects of Sb,Sm, and Sn additions on the microstructure and mechanical properties of Mg-6Al-1.2Y-0.9Nd alloy显示文摘The microstructure and mechanical properties of Mg-6Al-1.2Y-0.9Nd magnesium alloy with Sb, Sm, or Sn addition were investigated through X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The results show that small amounts of Sb, Sm, and especially Sn can refine the grains of the alloy. High melting point Sb3Y5, Al2Sm, and Nd5Sn3 intermetallic compounds can be formed respectively when Sb, Sm, and Sn are added to the alloy. Sb and Sm can improve the tensile strength of the alloy at ambient and elevated temperatures. The tensile strength of the alloy with Sm addition is the highest at 293 and 423 K. However, the tensile strength of the alloy with Sn addition is the highest at 448 K.LI Kejie LI Quanan JING Xiaotian CHEN Jun ZHANG Xingyuan 2009Rare Metals2009,28,5:39
7Arc erosion of AgSnO_2 electrical contacts at different stages of a break operation显示文摘Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation.A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity.The arc current is terminated at different stages as the arc is drawn between the contacts enabling a study of the arcing phenomena up to that point.Surface profiling of the contacts is conducted to determine the extent of erosion at the different stages as the arc is drawn.Spectral analysis is also conducted on the arc and then related to the extent of erosion.The results show that particular features occur at different stages as the arc is drawn.As the arc is initially established,it goes through an 'Arc Generation' regime where the arc roots are small and immobile on both the anode and the cathode.Material transfer occurs mainly from anode to cathode.The spectral analysis indicates that Sn and O species dominate the arc followed by the Ag species.As the arc is drawn further and enters the 'Arc Degeneration' regime,the anode undergoes significantly larger erosion than the cathode.Also,both contacts indicate that multiple arc roots have formed,which are highly mobile in the later stages of the discharge.The spectral analysis indicates that Ag and N species are in high concentrations compared to other species.The mechanisms of erosion and deposition are discussed in relation to the species within the arc discharge.For the complete break operation,it is found that the anode undergoes major erosion,and it is thought that the gaseous ions species do not dominate the arc under these conditions of short arcs and voltage <42 V to cause cathode erosion.J. Swingler A. Sumption 2010Rare Metals2010,29,3:40
8Effect of SiC whiskers on the oxidation protective properties of SiC coatings for carbon/carbon composites显示文摘以便有效地采用唯一的高温度碳 / 碳的机械性质合成底层,原文如此,涂层增强了由原文如此,络腮胡子被包装硬化方法准备。效果原文如此,单个层的涂层和双层涂层的氧化抵抗性质上的络腮胡子被调查。原文如此络腮胡子在单个层原文如此涂层在反氧化性质上有小效果,但是显然改进热吃惊性质。有内部层的增强的涂层的双层涂层与原文如此内部层的涂层比双层涂层展出更多的完美的反氧化能力。SHI Xiaohong LI Hejun FU Qiangang LI Kezhi ZHANG Xiulian 2006Rare Metals2006,25,1:33
9Effect of vanadium occurrence state on the choice of extracting vanadium technology from stone coal显示文摘钒从的抽取技术借助于 no-salt-roasting 投掷煤并且冲淡酸答案沥滤处理有低污染,低投资,以及高钒沥滤效率的优点,它为扩大申请使它成为最好的技术。在现在的学习,钒出现的效果在石头煤声明钒的沥滤的效率上的温度和添加剂代理人被学习,烤。结果显示提取的钒技术上的钒出现状态的效果是明显的。如果在石头煤的钒部件在非结晶的阶段形式存在,这类石头煤能被 no-slat-roasting 对待并且冲淡酸答案沥滤技术;当忍受钒的水晶的阶段在石头煤存在时,烤的添加剂必须被增加破坏这种水晶的形式以便高获得钒沥滤率。WANG Mingyu XIANG Xiaoyan ZHANG Liping XIAO Liansheng 2008Rare Metals2008,27,2:32
10Recent progress in carbon/lithium metal composite anode for safe lithium metal batteries显示文摘Owing to their very high theoretical capacity,lithium(Li) metal anodes regain widespread attentions for their promising applications for next-generation highenergy-density Li batteries(e.g., lithium–sulfur batteries,lithium–oxygen batteries, solid-state lithium metal batteries). However, the inherent bottleneck of Li metal anodes,especially the growth of Li dendrites and the related safety concerns, should be well addressed. Owing to their featured micro-/nano-porous structures and intriguing physical properties, nanocarbon materials have been applied as host materials for Li metal anodes. This review summarizes the recent progress in the development of porous nanocarbon materials for safe Li metal anodes. The perspectives regarding the challenges and future development of employing micro-/nano-porous carbon materials in Li metal anodes are also included.Tao Li He Liu Peng Shi Qiang Zhang 2018Rare Metals2018,37,6:32
11Leaching and mass transfer characteristics of elements from ion-adsorption type rare earth ore显示文摘The differences in the leaching and mass transfer characteristics of ion-adsorption type rare earth ore between rare earth and non-rare earth impurities were investigated. It is determined that the leaching kinetics of rare earths(REs), Mg and Ca could be described by the shrinking-core model. The leaching rate is controlled by inner diffusion and is in the order of Mg [ Ca [ RE. The apparent activation energy is 8.48, 6.79 and 6.32 k J mol-1,respectively. In leaching system of Al, the leaching efficiency decreases with the increase in temperature because of hydrolysis reactions. The leaching efficiency of aluminum increases firstly and then decreases with the passage of time when the temperature is higher than 35 °C.Besides, there is a good consistency in leaching characteristics and mass transfer, and the order of the time-topeak is Mg \ Ca \ RE \ Al. Therefore, rare earth and non-rare earth may be partly separated by expanding the separation coefficient. The research could provide a theoretic basis for the separation of rare earth and non-rare earth impurities. Furthermore, compound leaching with magnesium salt and calcium salt is innovatively proposed to solve the problem of calcium and magnesium nutrient loss in the soil as well as eliminate ammonia-nitrogen emissions from the source.Yan-Fei Xiao Zong-Yu Feng Gu-Hua Hu Li Huang Xiao-Wei Huang Ying-Ying Chen Ming-Lai Li 2015Rare Metals2015,34,5:28
12Leaching of vanadium from stone coal with sulfuric acid显示文摘The effects of roasting, mass ratio of H2SO4 to stone coal, leaching temperature, liquid-to-solid ratio, grinding fineness of stone coal, and two-stage counter-current leaching on the vanadium leaching ratio were studied. The results show that the vanadium leaching ratio of roasted stone coal through two-stage counter-current leaching can reach 65.1% at the mass ratio of H2SO4 to stone coal of 20%, leaching temperature of 95°C, leaching time of 30 h, liquid-to-solid ratio of 1.1 mL-g-1, and grinding fineness of 0.1 mm, which can serve as an experimental basis for the production of vanadium from stone coal.WANG Mingyu XIAO Liansheng LI Qinggang WANG Xuewen XIANG Xiaoyan 2009Rare Metals2009,28,1:26
13Effects of the two-step ageing treatment on the microstructure and properties of 7B04 alloy pre-stretched thick plates显示文摘The effects of the two-step ageing parameters (temperature and time) on the mechanical properties and electrical conductivity of 7B04 (Al-Zn-Mg-Cu) pre-stretched thick plates were studied. The results reveal that the initial T1 ageing contributes a major increase of the tensile strength, and the 0.2% proof stress value reaches 482 MPa after ageing for 7 h at 115°C. Behavioral differences in the tensile properties of the alloy after the two-step ageing treatment were less with the first-step ageing at 115°C for different time periods (7, 14, and 21 h). The effects of the second ageing parameters on the properties and microstructure of the 7B04 alloy were remarkable. TEM analysis of the samples aged at Temper I (7 h at 115°C + 12 h at 160°C) and Temper II (7 h at 115°C + 16 h at 165°C) indicates that two kinds of phases, i.e. η′ and η phases, precipitate from the matrix and efficiently improve the tensile strength of the alloy, and the grain boundary precipitates are coarse and discrete. There are obvious precipitate free zones (PFZs) along the grain boundary in the microstructure of the alloy after the two-step ageing treatment.LI Zhihui XIONG Baiqing ZHANG Yong 'an ZHU Baohong WANG Feng LIU Hongwei 2007Rare Metals2007,26,3:24
14Preparation and microstructure characterization of a nano-sized Ti^(4+)-doped AgSnO_2 electrical contact material显示文摘A Ti4+-doped nano-structured AgSnO2 material was prepared using sol-gel method and characterized by X-ray diffraction (XRD), transmis-sion electron microscopy (TEM), and scanning electron microscopy (SEM). The results show that Ti4+ cations are successfully doped into the crystal lattice of SnO2, and thus significantly improve the electrical conductivity of the sample. Furthermore, the coating of Ag on Ti4+-doped SnO2 nano-sized particles enhances the surface wettability and enables the resulting AgSnO2 material to have better mechanical properties.ZHENG Ji LI Songlin DOU Fuqi LI Tonghui 2009Rare Metals2009,28,1:24
15Modification mechanism of cerium on the Al-18Si alloy显示文摘在不同扔的状态下面的高级低共熔体的 Al-Si 合金上的稀土元素铈(Ce ) 的效果被光显微镜和量的图象分析学习了。尺寸和在铸造物的主要的硅的数量随 melt 的增加的 Ce 的增加减少,这被发现。好 facetted 形状的从分叉的形状的同时主要的硅变化。尽管在铸造物的最容易溶解的硅上的修正也随 melt 的增加的 Ce 的增加改善,离开主要的硅的最容易溶解的硅上的修正的效果在到主要的硅的最容易溶解的硅结束上是比那更明显的。修正机制借助于扫描详细被分析电子显微镜与精力装备了 X 光检查和热力学分析的散分析,它在反应和反应平衡的标准吉布斯精力在变化上包括了分析。ZHANG Henghua DUAN Haili SHAO Guangjie XU Luoping YIN Junlin YAN Biao 2006Rare Metals2006,25,1:23
16Effect of oxidization on enrichment behavior of TiO_2 in titanium-bearing slag显示文摘Due to the dispersed distribution of the titanium component in various mineral phases and very fine grain size, it is difficult to recover the titanium component from the slag. In order to utilize titanium resources, selective enriching and selective growing of the titanium component from the molten slag is expected. In this paper, the selection of the best tita- nium enrichment phase and the effect of oxidization on the enrichment of titanium by blowing air into the molten slag were studied. The results showed that through oxidizing the slag, the content of the perovskite phase increases while that of the other titanium-bearing mineral phases decreases until they disappear. Most titania resources were enriched into the perovskite phase and increase in size. The process of enrichment and growth is easily carried out.WANG Mingyu LI Liaosha ZHANG Li ZHANG Linnan TU Ganfeng SUI Zhitong 2006Rare Metals2006,25,2:23
17Microstructure and formation mechanism of titanium matrix composites coating on Ti-6Al-4V by laser cladding显示文摘Laser cladding experiments were done on a 5-kW continuous wave CO2 laser to synthesize TiC and TiB rein- forced titanium matrix composite coatings on Ti-6Al-4V alloy with a mixture of Ti and B4C precursor powder. The ther- modynamics of the reactions were calculated and analyzed. The microstructure and phase evolution of TiB and TiC com- posites were investigated. The results showed that the chemical reaction between Ti and B4C would release much heat, and these compounds, TiC, TiB, and small amount of TiB2, can be formed on the surface of Ti-6Al-4V alloy if the supplied en- ergy is sufficient to excite the reaction among the initial products. A good metallurgical bond between the coating and the substrate can be achieved. The microhardness of coating was irregular and the maximum value was approximately HV600.CAI Lifang ZHANG Yongzhong SHI Likai 2007Rare Metals2007,26,4:22
18Vanadium recovery from clay vanadium mineral using an acid leaching method显示文摘包括直接酸的沥滤的一种技术,钒降水与碱,钠氢氧化物重新沥滤,杂质由由烤步调整 pH 价值,有铵氯化物的降水钒,和钒 pentoxide 搬迁根据 Xichuan 的特征被建议泥土钒矿物质。影响象温度和硫磺的酸的集中那样的沥滤的钒的因素被调查并且优化。试验性的结果显示 V2O5 的摘录比率能分别地在 3% 的钠氯酸盐比率和 3% 的锰二氧化物比率到达 94% 和 92% 。一个完全化学的降水方法被采用清除并且在酸的沥滤溶液充实钒。X 光检查衍射(XRD ) 模式和钒 pentoxide 的纯净分析显示最后的钒 pentoxide 的纯净能到达 99% 并且遇见标准说明。全部的恢复能到达大约 75% 。这种技术作为与传统的咸烤方法相比有简洁,更少的投资,和更多的环境安全的特征。LI Haoran FENG Yali LIANG Jianglong LUO Xiaobing DU Zhuwei 2008Rare Metals2008,27,2:23
19Effect of yttrium on the microstructure of a semi-solid A356 Al alloy显示文摘The semi-solid slurry of an A356 Al alloy, which was grain-fined by yttrium, was manufactured by low temperature pouring. The effects of grain-refining on the morphology and the grain size of the primary α phase in the semi-solid A356 Al alloy were researched. The results indicate that the semi-solid A356 Al alloy with particle-like and rosette-like primary α-Al can be prepared by low temperature pouring from a liquid grain-refined A356 alloy. The grain size and particle morphology of primary α-Al in the A356 Al alloy are markedly improved by the addition of 0.5 wt.% Y. The fining mechanism of Y on the morphology and grain size of the primary α-Al in the semi-solid A356 Al alloy was delved.LIUZheng HU Yongmei 2008Rare Metals2008,27,5:23
20Heat-treated microstructure and mechanical properties of laser solid forming Ti-6Al-4V alloy显示文摘The effects of heat treatment on the microstructure and mechanical properties of laser solid forming (LSF) Ti-6Al-4V alloy were investigated. The influences of the temperature and time of solution treatment and aging treatment were analyzed. The results show that the microstructure of LSFed samples consists of Widmanstatten α laths and a little acicular in columnar prior β grains with an average grain width of 300 μm, which grow epitaxially from the substrate along the deposition direction (Z). Solution treatment had an important effect on the width, aspect ratio, and volume fraction of primary and secondary α laths, and aging treatment mainly affects the aspect ratio and volume fraction of primary α laths and the width and volume fraction of secondary α laths. Globular α phase was first observed in LSFed samples when the samples were heat treated with solution treatment (950°C, 8 h/air cooling (AC)) or with solution treatment (950°C, 1 h/AC) and aging treatment (550°C, above 8 h/AC), respectively. The coarsening and globularization mechanisms of α phase in LSFed Ti-6Al-4V alloy during heat treatment were presented. To obtain good integrated mechanical properties for LSFed Ti-6Al-4V alloys, an optimized heat treatment regimen was suggested.ZHANG Shuangyin LIN Xin CHEN Jing HUANG Weidong 2009Rare Metals2009,28,6:22
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