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Preparation of high concentration Polyaluminum Chloride with high Al_c Content by Membrane Distillation

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Chinese Journal of Chemical Engineering 2011年第1期19卷 173-176页

作者：赵长伟王军栾兆坤 State Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

A direct contact membrane distillation（DCMD）process was applied to prepare high concentration polyaluminum chloride（PACl）with high Alc *** changes in total Al concentration（AlT）and Al species distribution were *** results showed that AlT increased but the flux decreased with operating time during the DCMD *** Alc content increased from 65%to 81%while the Alb content decreased from 34% to 18%,and the Ala content was almost 1%in the process.2.1 mol·L 1PACl with 81%Alc was successfully prepared by DCMD *** the DCMD is an effective method for preparing high concentration PACl with high Alc content.

关键词： polyaluminum chloride high concentration membrane distillation preparation

Behavior of SiO_2 in the leaching process of alumina clinker with high concentration

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Journal of University of Science and Technology Beijing 2008年第5期15卷 538-542页

作者： Bin Chen Xiaobin Li Guihua Liu School of Metallurgical Science and Engineering Central South University Changsha 410083 China

It is essential for alumina production by alkaline process to know the behavior of minerals containing Al and Si in basic solution,and the behavior of SiO2 in the process of clinker leaching is an important portion. To study the behavior of SiO2 in the process of high concentration clinker leaching,experiments were carried out in home-made reactors. The results indicate that factors,such as temperature,time,Al2O3 concentration,as well as SiO2 concentration,have profound impact on the SiO2 and Al2O3 concen-tration of pregnant liquor during the high concentration leaching. However,sodium carbonate and free caustic soda concentrations have no remarkable effect on it,thus they are the secondary factors compared with Al2O3 concentration. The concentration of SiO2 in the pregnant liquor could be reduced to a lower level when the major effect parameters of this process are controlled properly.

关键词： clinker leaching high concentration silica mechanism of secondary reaction

Preparation of high concentration polyaluminum chloride by chemical synthesis-membrane distillation method with self-made hollow fiber membrane

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Journal of Environmental Sciences 2012年第5期24卷 834-839页

作者： Changwei Zhao Yong Yan Deyin Hou Zhaokun Luan Zhiping Jia Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

A method of direct contact membrane distillation （DCMD） with a self-made hollow polyvinylidene fluoride membrane was applied to prepare high concentration polyaluminum chloride （PACl） with high Alb content based on chemical synthesis. The permeate flux and Al species distribution were investigated. The experimental results showed that the permeate flux decreased from 14 to 6 kg/（m2·hr） at the end of the DCMD process, which can be mainly attributed to the formation of NaCl deposits on the membrane surface. The Alb content decreased slightly, only from 86.3% to 84.4%, when the DCMD experiment finished, correspondingly the Alc content increased slightly from 7.2% to 8.5%, and the Ala content remained at 7% during the whole DCMD process. A PACl with Alb content of 84% at total aluminum concentration 2.2 mol/L was successfully prepared by the chemical synthesis-DCMD method.

关键词： polyaluminum chloride membrane distillation high concentration high Alb content PVDF hollow fiber membrane

EXPERIMENTAL INVESTIGATIONS ON DIFFUSION CHARACTERISTICS OF high concentration JET FLOW IN NEAR REGION

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Journal of Hydrodynamics 2001年第1期13卷 117-121页

作者： Zhang Yan, Wang Dao-zeng, Fan Jing-yu Shanghai University, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai 200072, China Inst. of Appl. Math. and Mech. Shanghai Univ. Shanghai 200072 China

WT5”BZ]The diffusion characteristics of the high concentration jet flow issued from a round nozzle above the free surface into moving waterbody were experimentally investigated. By means of flow visualization technique, the diffusion behavior of the high concentration jet was observed and analysed, concentration distribution in the near region was obtained by sampling and quantitative measurements. Experimental results indicate that the diffusion mechanics of the high concentration jet flow are greatly influenced by initial momentum, buoyancy, turbulent structure, ambient current and boundary conditions, showing complicated flow patterns and concentration distribution characteristics that are different from previous results for submerged jets. [WT5”HZ]

关键词： et flow high concentration diffusion turbulent structure

Particle characteristics and rheological constitutive relations of high concentration red mud

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Journal of China University of Mining and Technology 2008年第2期18卷 266-270页

作者： WANG Xing QU Yuan-yuan HU Wei-wei CHEN Jie ZHAO Xue-yi WU Miao School of Electromechanical and Information Engineering China University of Mining ＆ Technology Beijing 100083 China Electromechanical Engineering and Technology Institute China University of Mining ＆ Technology Beijing 100083 China

Red mud has relatively small solid particles （d50= 13.02 μm） and will flow in paste form under high pressure during pipeline transport. Red mud belongs to a two-phase flow of materials with high viscosity and a high concentration of non-sedimentation, homogeneous solid-liquids. It is difficult to test its rheological properties under atmospheric pressure. Measurements such as rotational viscometry can not reflect the real state of the material when it is flowing in a pipe. Tested rheological parameters are somewhat higher than the actual values. In our investigation, grain shape, distinctive modality and grain size distribution of red mud were tested. Based on the principle of tube measurement, rheological experiments on red mud at different concentrations were carried out by using our independently developed tube-type pressure theology test facility, and obtained constitutive equations. We conclude that red mud behaves as non-Newtonian pseudo-plastic fluid in pipe flows. Its consistency and power-law indices vary considerably with different concentrations.

关键词： high concentration non-Newtonian fluid rheological constitutive relations red mud tube-pipe flow method tube-type pressure rheology test facility

Experimental studies on resistance characteristics of high concentration red mud in pipeline transport

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Journal of Coal Science & Engineering(China) 2008年第1期14卷 157-161页

作者：王星瞿圆媛胡伟伟陈洁赵学义吴淼 School of Electromechanical and Information Engineering China University of Mining and Technology (Beijing)Beijing 100083China Electromechanical Engineering and Technology Institute China University of Mining and Technology (Beijing)Beijing 100083China

Red mud will flow in paste form under high pressure during pipeline *** belongs to a two-phase flow of materials with high viscosity and a high concentration of non-sedimentation,homogeneous *** pipeline transport,its resistance char- acteristics will be influenced by such factors as grain size,velocity,concentration,density, grain composition and pipe diameter etc..With the independently developed small-sized tube-type pressure resistance test facility,studied the resistance characteristics of red mud concerning the three influencing factors,paste concentration,velocity and pipe diameter, which attract the most attention in *** fine grain size of the red mud is d_(50)= 13.02μ*** to the experimental results,the pressure loss in transport will in- crease along with the increase of velocity and will fall along with the increase of pipe di- ameter.A 1% difference in paste concentration will result in a 50%～100% difference in pipeline resistance *** experimental data is hoped to be direct guidance to the design of high concentration and viscous material pipeline transport system.

关键词： high concentration homogeneous laminar flow pipeline transport resistancecharacteristics particle characteristics

Homogeneous Acetylation of Cellulose at Relatively high concentrations in an Ionic Liquid

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Chinese Journal of Chemical Engineering 2010年第3期18卷 515-522页

作者：曹妍张军何嘉松李会泉张懿 Laboratory of Green Process Engineering Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China Beijing National Laboratory for Molecular Sciences (BNLMS) Key Laboratory of Engineering Plastics (KLEP) Joint Laboratory of Polymer Science and Materials Institute of Chemistry Chinese Academy of Sciences (CAS) Beijing 100190 China

At relatively high cellulose mass concentrations(8%,10%,and 12%),homogeneous acetylation of cellulose was carried out in an ionic liquid,1-allyl-3-methylimidazolium chloride(AmimCl).Without using any catalyst,cellulose acetates(CAs)with the degree of substitution(DS)in a range from 0.4 to 3.0 were synthesized in *** effects of reaction time,temperature and molar ratio of acetic anhydride/anhydroglucose unit(AGU) in cellulose on DS value of CAs were *** synthesized CAs were characterized by means of FT-IR, NMR,and solubility,mechanical and thermal *** the acetylation,the used ionic liquid AmimCl was easily recycled and *** study shows the potential of the homogeneous acetylation of cellulose at relatively high concentrations in ionic liquids in future industrial applications.

关键词： cellulose high concentration acetylation homogeneous ionic liquid

Estimation of Collection Efficiency Depended on FeedParticle concentration for Axial Flow Cyclone DustCollector

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Journal of Thermal Science 1999年第3期8卷 143-157页

作者： Akira Ogawa(Department of Mechanical Engineering, College of Engineering, Nihon University T-963-8642.Tokusada, Tamura-machi, Kooriyama-shi, Japan. Fax.0249-56-8860) Department of Mechanical Engineering College of Engineering Nihon University T-963-8642 Japan

A cyclone dust collector is applied in many industries. Especially the axial flow cyclone is the mostsimple construction and it keeps high reliability for maintenance. On the other hand, the collectionefficiency of the cyclone depends not only on the inlet gas velocity but also on the feed particle concentration. The collection efficiency increases with increasing feed particle concentration. However untilnow the problem of how to estimate the collection efficiency depended on the feed particle concentrationis remained except the investigation by Muschelknautz & Brunner~[6]. Therefore in this paper one ofthe estimate method for the collection efficiency of the axial flow cyclones is proposed. The applicationto the geometrically similar type of cyclone of the body diameters D_1=30, 50, 69 and 99 mm showedin good agreement with the experimental results of the collection efficiencies which were described indetail in the paper by Ogawa & Sugiyama~[8].

关键词： axial flow cyclone dust collector collection efficiency cut-size Reynoldsnumber centrifugal effect re-entrainment in dust bunker critical feed particle concentration fly-ash high concentration low concentration.

Predictability of sediment transport in the Yellow River using selected transport formulas

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International Journal of Sediment Research 2008年第4期23卷 283-298页

作者： D.S.van MAREN Postdoctoral Fellow Delft University of Technology Faculty of Civil Engineering and Geosciences the Netherlands and WL | Delft HydraulicsPO Box 177 2600 MH Delft The Netherlands.

This paper evaluates the applicability of the sediment transport methods developed by Engelund and Hansen, Ackers and White, Yang et al., and van Rijn, together with the Wuhan methods developed in China, to the Yellow River, which has highly concentrated and fine-grained sediment. The sediment data includes over 1000 observations from the Yellow River, 32 sets of data from a canal, and 266 sets of data from laboratory flumes. The best predictions were obtained by the Yang 1996 method, the Wuhan method, and the modified Wuhan method by Wu and Long, while reasonably good predictions were also provided by the van Rijn 2004 method. The Engelund and Hansen, the Ackers and White, and the van Rijn 1984 methods in their original forms are not applicable to the Yellow River. The predicted results for total load concentrations were as good as for bed-material concentrations, even though the total load includes a large portion of wash load.

关键词： Yellow River Sediment transport high concentration Fine sediment