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Effect of impurity ions on preparation of novel saponifier for rare earth extraction

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Journal of Rare Earths 2013年第9期31卷 905-910页

作者：肖燕飞冯宗玉黄小卫黄莉徐旸侯永可王猛 National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous MetalsGrirem Advanced Materials Co.Ltd.

Magnesium bicarbonate, prepared by the carbonation of magnesium hydroxide slurry, was used as a novel saponifier to eliminate the ammonia nitrogen pollution in the rare earth extraction separation process. The effect of impurity ions introduced by system on the carbonation reaction of magnesium hydroxide was studied in the work. The results showed that the presence of Ca2＋could lead to side reactions so as to reduce the conversion rate of magnesium hydroxide, and a small number of rare earth ions would have great influence on the carbonation reaction. What’s more, there was no influence on carbonation reaction with the low concen-tration of Na＋or Mg2＋, the conversion rate of magnesium hydroxide could reach above 96%. This paper showed a practical theory which could provide scientific guidance for the preparation of novel saponifier in rare earth extraction separation process.

关键词： rare earths magnesium bicarbonate saponifier carbonation impurity ions

Stress corrosion cracking behavior of high-strength mooring-chain steel in the SO_(2)-polluted coastal atmosphere

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International Journal of Minerals,Metallurgy and Materials 2022年第6期29卷 1186-1196页

作者： Menghao Liu Zhiyong Liu Cuiwei Du Xiaoqin Zhan Xiaojia Yang Xiaogang Li corrosion and Protection Center University of Science and Technology BeijingBeijing 10083China Zhengmao Group co. Ltd.Zhenjiang 212000China

21Cr2NiMo steel is widely used to stabilize offshore oil platforms;however,it suffers from stress-corrosion cracking(SCC).Herein,we studied the SCC behavior of 21Cr2NiMo steel in SO_(2)-polluted coastal *** tests revealed that the addition of SO_(2) increased the corrosion *** characterization showed that SO_(2) addition densified the corrosion products and promoted ***,slow strain rate tests demonstrated a high susceptibility to SCC in high SO_(2) *** morphologies revealed that the stress-corrosion cracks initiated at corrosion pits and the crack propagation showed transgranular and intergranular cracking *** conclusion,SCC is mix-controlled by anodic dissolution and hydrogen embrittlement mechanisms.

关键词： corrosion marine atmospheres mooring-chain steel SO_(2)-polluted coastal atmospheres stress-corrosion cracking

Structure and magnetic properties of TbCu_7-type melt-spun Sm–Fe–B alloys

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Rare Metals 2019年第2期38卷 151-156页

作者： Chuan-Jiang Zheng Yang Luo Dun-Bo Yu Wen-Long Yan Hong-Wei Li Yong-Jun Mao Shuo Lu Ning-Tao Quan National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals Grirem Advanced Materials co. Ltd.

The melt-spun SmFe_(12)B_x(x = 0, 0.50, 0.75,1.00, 1.25 and 1.50) ribbons were prepared at 40 m·s^(-1),and their structure and magnetic properties were studied by powder X-ray diffraction(XRD), vibrating sample magnetometer(VSM) and transmission electron microscopy(TEM). XRD results indicate that SmFe_(12)B_x alloys with 0.50 ≤ x ≤ 1.00 are composed of single-phase TbCu_7-type structure. Moreover, it is found that the boron addition can inhibit the emergence of soft magnetic phase a-Fe and result in the increase in the axial ratio c/a. After annealing at 650 ℃ for 0.5 h, the metastable phase TbCu_7 initially decomposes into the stable phase Sm_2Fe_(14)B(Nd_2Fe_(14)B-type) and a-Fe. The value of magnetic moment per Fe atom increases slightly from 1.75 uB for boron-free sample to 1.80 uB for the x = 0.75 sample and then decreases *** addition, the best magnetic properties of maximum energy product [(BH)_(max)] of 14.56 kJ·m^(-3), coercivity(H_(cj))of 172.6 kA·m^(-1) and remanence(B_r) of 0.45 T are obtained for the SmFe_(12)B_(1.00) alloy. Based on transmission electron microscopy(TEM) results, the average size of grains is around 197 nm for B-free sample and decreases to 95 nm for x = 1.00 sample, indicating that the addition of boron can refine grains.

关键词： TbCu7-type structure Sm-Fe-B ribbons Phase formation Magnetic moment Microstructure

CFD simulation study of the effect of baffles on the fluidized bed for hydrogenation of silicon tetrachloride

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Chinese Journal of Chemical Engineering 2022年第5期35卷 219-228页

作者： Ning Liu Xingping Liu Fumin Wang Feng Xin Mingshuai Sun Yi Zhai Xubin Zhang School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China Xinte Energy co. Ltd.UrumchiXinjiang 830011China

In this study,the effect of channel baffles and louver baffles on the flow pattern in the large-scale industrial fluidized beds was studied by computational fluid dynamics(CFD)***,the effect of flow pattern on the chemical reaction performance was studied for the first *** results showed that the gas velocity distributed more uniformly,solid particles dispersed more homogeneously and aggregation scarcely occurred in the fluidized bed with louver baffles than that with channel *** residence time distribution indicated that louver baffles remarkably suppressed gas back-mixing in comparison with channel *** reasonable agreements of pressure distribution and reaction results between the simulation in the bed with channel baffles and the data on a large-scale industrial apparatus demonstrated the accuracy of the CFD *** predicted conversion of SiCl_(4) in the bed with louver baffles(27.44%)was higher than that with channel baffles(22.69%),indicating that louver baffles markedly improved the performance of the fluidized *** study could provide useful information for future structural improvements of baffles in large-scale fluidized beds.

关键词： Fluidized-bed Baffle Gas-solids flow Hydrogenation computational fluid dynamics

Curing kinetics and mechanical properties of bio-based composite using rosin-sourced anhydrides as curing agent for hot-melt prepreg

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Science China(Technological Sciences) 2017年第9期60卷 1318-1331页

作者： ZHANG XuFeng WU YunQiQiGe WEI JiaHu TONG JianFeng YI XiaoSu Beijing Institute of Aeronautical Materials Beijing 100095 China Aviation composite corparation (Beijing) Science and Technology co. Ltd Beijing 101300 China

In this study, a novel bio-based thermosetting system has been developed from epoxy resin （EP）, with rosin-sourced anhydrides （maleopimaric acid, RAM） as curing agent and imidazole type latent catalyst （two amino imidazole salt complex, IMA）, to be used as matrix for hot-melt prepreg curing at mid-temperature. For comparison, the epoxy resin system with petroleum sourced hardener methylhexahydrophthalicanhydride （MHHPA） was also examined. The curing behaviour and mechanism were investigated by non-isothermal differential scanning calorimeter （DSC） analysis and Fourier transform infrared （FTIR） spectra. The results showed that the curing course of bio-based epoxy resin system containing RAM included two stages, which were the reaction between the free carboxyl group of RAM and oxirane ring under the acceleration of IMA, and the main reaction attributed to the reaction between anhydride and oxirane. According to Kissinger method, the reaction activation energy （E,） of two stages were 68.9 and 86.5kJmo1-1, respectively. The Eo of EP/MHHPA and EP/IMA resin system were 81.04 and 77.9kJmol-I. The processing property of EP/RAM/IMA system, i.e. the relationship between viscosity-temperature-time, was characterized by cone-plate viscometer aim to decide the processing parameter ofprepreg preparation. The effect of RAM content on mechanical performance and dynamic mechanical property was investigated. Noteworthily, compared with the laminates with EP/MHHPA as matrix, the laminates with RAM as hardeners achieved a 44%, 73% and 70℃ increase in bending strength, bending modulus and the glass transition temperature, respectively, due to the bulky hydrogenated phenanthrene ring structure incorporated into the cross-linking networks. When the fiber volume fraction reached 47%, the mechanical property of the laminates prepared with hot melt prepreg was superior or comparable to that of composites with pure petroleum sourced matrix. RAM as cross-linking agent of epoxy resin holds a g

关键词： bio-based epoxy resin rosin cure kinetics hot-melt prepreg mechanical property

Effect of Structure Pattern on the Performance of X80 Pipeline Steel

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Journal of Iron and Steel Research International 2011年第S1期18卷 874-877页

作者： REN Yi,LIU Wen-yue,WANG Shuang,ZHANG Shuai (Technical Center of Anshan Iron & Steel co.Ltd.,Anshan 114009,Liaoning,China) Anshan Iron & Steel co Ltd Ctr Tech Anshan 114009 Liaoning Peoples R China

The microstructure,dislocation and precipitation phases of X80 pipeline steel produced with different processes were analyzed by optical microscope and transmission electron microscope (TEM) contrastively,and the influence of structure pattern on the performance of X80 pipeline steel was *** result shows that the effects of acicular ferrite grain size,precipitate phase distribution,dislocation density and morphology on the material strength,toughness and brittle transmission temperatures were distinct,and solid solution strengthening,fine grain strengthening,dislocation strengthening and precipitation strengthening were the strengthening ways of X80 pipeline steel.

关键词： pipeline steel acicular ferrite dislocation precipitated phase toughness

Numerical simulation and experimental verification of a novel double-layered split die for high-pressure apparatus used for synthesizing superhard materials

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International Journal of Minerals,Metallurgy and Materials 2019年第3期26卷 377-385页

作者： Zhuo Yi Wen-zhi Fu Ming-zhe Li Rui Li Liang Zhao Li-yan Wang Roll Forging Institute Jilin University college of Materials Science and Engineering Jilin University Changchun Ruiguang Science & Technology co. Ltd.

Based on the principles of massive support and lateral support, a novel double-layered split die(DLSD) for high-pressure apparatus was designed to achieve a higher pressure-bearing capacity and larger sample cavity. The stress distributions of the DLSDs with different numbers of divided blocks were investigated by the finite element method and compared with the stress distributions of the conventional belt-type die(BTD). The results show that the cylinders and first-layer supporting rings of the DLSDs have dramatically smaller stresses than those of the BTD. In addition, increasing the number of divided blocks from 4 to 10 gradually increases the stress of the cylinder but has minimal influence on the stress of the supporting rings. The pressure-bearing capacities of the DLSDs with different numbers of divided blocks, especially with fewer blocks, are all remarkably higher than the pressure-bearing capacity of the BTD. The contrast experiments were also carried out to verify the simulated results. It is concluded that the pressure-bearing capacities of the DLSDs with 4 and 8 divided blocks are 1.58 and 1.45 times greater than that of the BTD. This work is rewarding for the commercial synthesis of high-quality, large-sized superhard materials using a double-layered split high-pressure die.

关键词： split die prismatic cylinder pressure-bearing capacity high-pressure apparatus superhard material FEM

Removal of sulfamethoxazole by nanofiltration membrane

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第11期11卷 868-878页

作者： Su-hua WU Hua-qiang CHU Bing-zhi DONG Jun-ru ZHOU Yu HUANG School of Environmental Science and Engineering Tongji University Shanghai 200092 China Shanghai Purge Filtration Technology co. Ltd Shanghai 200444 China

The retention of sulfamethoxazole (SMZ) by nanofiltration (NF) membranes is strongly influenced by the pH value of the solution. The retention of SMZ reaches its peak value when the solution pH rises above its pKa2 value as the compound transforms into a negatively charged species. Charge repulsion is the main mechanism involved in SMZ removal by NF membranes. In this study, the removal of SMZ by NF membranes, as a function of solution chemistry, was examined at pH 8.9 to investigate the effect of solution conditions on charge repulsion. The results show that the retention of negatively charged SMZ is relatively independent of SMZ concentration, and an increase in the ionic strength of the solution causes a relatively small reduction in retention. A small effect of humic acid (HA) on SMZ retention was noticed at pH 8.9, which can be explained by a small but insignificant improvement in the zeta potential of the membrane caused by HA at high pH values. However, it was found that SMZ concentration in the feed decreased significantly in solutions containing tannic acid (TA). The Adams-Bohart model was applied to our experimental data and was found to be suitable for describing the initial part of the breakthrough curves. The adsorptive parameters of the membrane were determined.

关键词： Pharmaceutically active compounds (PhACs) Nanofiltration (NF) membrane Electronic exclusion Adsorption Sulfamethoxazole (SMZ)

Zrs5.8Al19.4（co1-xCux）24.8 （x = 0-0.8 at.%） bulk metallic glasses for surgical devices applications

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Journal of Iron and Steel Research International 2018年第6期25卷 644-649页

作者： Kai-ming Han Jian-bing Qiang Ying-min Wang1 Bing-bing Zhao Peter Haussler Key Laboratory of Materials Modification by Laser Ion andElectron Beams (Ministry of Education) Dalian Universityof Technology Dalian 116024 Liaoning China ArcX coating Hub Asia Hoganais (China) Co. Ltd.Shanghai 201799 China Physics Institute Chemnitz University of Technology09107 Chemnitz Germany

Zr-Al-co-Cu bulk metallic glasses （BMGs） are promising surgical materials. By using the electron concentration criterion for BMG composition design, a series of Zr55.8Al19.a（co1-xCux）24.8 （x = 0-0.8 at.%） alloys were produced, of which BMG rod samples with different diameters were made by copper mold casting. Among these alloys, the Zr55.8A119.4co17.36Cu7.44 BMG exhibited a centimeter-scale glass formation size （dmax = 12 mm）, an ultrahigh strength （δy = 2.04 GPa）, a large room-temperature plasticity （εp = 4.0%）, and a fracture toughness （KQ = 120 MPa m^l/2）, as well as good corrosion resistance in phosphate-buffered solution. The attAlnment of the combination of properties as large glass-forming ability with excellent mechanical and corrosion stability would suit the surgical devices applications.

关键词： Zr-Al-co-Cu Bulk metallic glass Biomedical material Mechanical property