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Influence of TiO_2 Mineralizer on the Crystalline Structure of cordierite Synthesized from Aluminum Slag

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Chinese Journal of Structural Chemistry 2005年第5期24卷 596-600,493页

作者：阮玉忠吴任平于岩 College of Materials Science and Engineering Fuzhou University Fuzhou 350002 China

By adding small amount of TiO2, aluminum slag could be used to synthesize cor- dierite. α-Al2O3, TiO2 and dehydrated talc could generate solid solution to accelerate the solid-state reaction to form cordierite. The experimental results show that the content of cordierite increases with the increase of TiO2 added. 3.0% of TiO2 is determined to be the best amount, because all crystalline substances are converted into cordierite at this content. Philips X’pert plus software analysis shows that when the content of TiO2 is from 0 to 1.0%, cordierite has the same hexagonal structure as the single crystal and the lattice parameters change slightly; when the content of TiO2 is from 1.0 to 2.0%, the cordierite still keeps hexagonal structure but the lattice parameters change greatly; when the content of TiO2 is from 2.0 to 3.5%, the cordierite is converted from hexagonal into rhombic and the lattice parameters change accordingly.

关键词： aluminum slag TiO2 mineralizer cordierite crystalline structure

Influence of Impurity Na_2O on Crystalline Structure of cordierite Synthesized from Aluminum Sludge

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Chinese Journal of Structural Chemistry 2005年第1期24卷 29-34页

作者：于岩阮玉忠杜育红吴任平 College of Materials Science and Engineering Fuzhou University Fuzhou 350002 China

关键词： aluminum slag TiO2 mineralizer cordierite crystalline structure

Influence of La_2O_3 on preparation and performance of porous cordierite from rice husk

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Journal of Rare Earths 2010年第4期28卷 614-617页

作者：郭伟陆洪彬冯春霞 Department of Materials Engineering Yancheng Institute of Technology

A porous cordierite was synthesized at 1350 ℃ using rice husk as silica source and pore forming agent, and La2O3 as fluxing agent. The crystal phases of the cordierite were analyzed by X-ray diffraction (XRD) and their microstructures were observed by scanning electronic microscopy (SEM). The flexural strength, porosity and thermal expansion coefficient of the porous cordierite samples were inves- tigated in detail. Results showed that when 5 wt.% La2O3 was added, the flexural strength, porosity and thermal...

关键词： porous ceramic cordierite rice husk lanthana

Influence of Fe_2O_3 Impurity on the Crystalline Structure of cordierite Synthesized from Waste Aluminum Slag

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Chinese Journal of Structural Chemistry 2005年第4期24卷 483-487页

作者： WUWei-Qing RUANYu-Zhong YUYan CollegeofMaterialsScienceandEngineering FuzhouUniversityFuzhou350002China

The influence of Fe2O3 impurity on the crystalline structure of cordierite synthesized from waste aluminum slag is discussed. XRD and SEM techniques were employed to characterize the crystalline structure and microstructure of each specimen. Philips X’pert plus software was used to determine the lattice parameters of each specimen. The results show that the Fe2O3 content of 0.8～1.6wt% is beneficial to the formation of cordierite, with the cordierite amount reaching 90wt%. So 0.8～1.6wt% is considered as the allowable Fe2O3 content in the specimens and 0.8wt% is determined to be the best after overall analysis. Plus software analysis shows that the cordierite in each specimen has the same symmetrical hexagonal structure as the single crystal, and the lattice parameters as well as the lattice dimensions change slightly.

关键词： aluminum slag cordierite Fe2O3 impurity crystalline structure

Synthesis,characterization and sintering behavior influencing mechanical,thermal and physical properties of pure cordierite and cordierite-ceria

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Journal of Advanced Ceramics 2015年第1期4卷 22-30页

作者： Marikkannan SENTHIL KUMAR Ayyasamy ELAYA PERUMAL T.R.VIJAYARAM School of Mechanical Building and Sciences VIT UniversityChennai-600127Tamil Nadu StateIndia Department of Mechanical Engineering Anna UniversityChennai-600025Tamil Nadu StateIndia

The study of cordierite ceramic is the need of the hour in present technological world for various advanced engineering applications.cordierite,which has relatively poor mechanical properties,has induced the use of various dopants to study the improvement in mechanical properties.Thirst of seeking new materials with good mechanical properties has revived the research on ceria doped cordierite.Present research conducted on pure cordierite and ceria doped cordierite ceramics has investigated the results of characterization and studied their suitability.Pure cordierite and cordierite-ceria(CeO_(2))composite ceramics synthesized for various stoichiometric composition(5-20 wt%)were compacted at 240 MPa and sintered between 600℃and 1350℃for 3 h.The characterization techniques used in this study were X-ray diffraction(XRD),thermogravimetric(TG)analysis and Fourier transform infrared(FTIR).The density was calculated using the Archimedes principle.Influence of the ceria addition on cordierite’s mechanical properties such as hardness,flexural strength and fracture toughness and on thermal properties as thermal expansion was studied.XRD results confirmed the presence of cordierite and ceria in the samples heat treated at 1350℃.Results of FTIR and TG analyses revealed the formation of cordierite and the effect of ceria addition.The mechanical properties studied were found to be encouraging and confirmed the suitability of cordierite-ceria as an alternate material for cordierite.

关键词： cordierite ceria(CeO_(2)) temperature phase transformation properties

Studies on the Structure and Properties of cordierite Synthesized by Talc-Magnesite

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Chinese Journal of Structural Chemistry 2007年第6期26卷 732-736页

作者：武秀兰王芬任强 College of Material Science & Engineering Shaanxi University of Science & Technology

Homogeneous cordierite has been synthesized at low cost by talc-magnesite and coal gangue as the main raw materials. The mechanism of synthesizing cordierite under such a composing system of raw materials, and the effect of temperature on the crystal cell parameters and microstructure and thermal expansion coefficient of cordierite crystal have been studied via testing methods of XRD, SEM, etc. The result shows that the homogeneous cordierite can be synthesized by the systematic composing materials of ＂talc-magnesite-coal gangue-talc＂ with heat pre-servation at 1350 ℃ for 1 h; as the keeping time is prolonged, Al^3＋ and Mg^2＋ in cordierite crystal are replaced by a few impurity ions such as Fe^3＋, Fe^2＋, etc., and the crystal cell parameters of cordierite present an increase trend; as the high-temperature heat preservation is prolonged, the content of glassy phase in the sample is increased, its density is improved, and its thermal expansion coefficient presents an increase trend.

关键词： talc-magnesite reaction mechanism cordierite crystal cell parameters thermal expansion coefficient

Preparation of cordierite Ceramic Using Mixtures of Ce^(4+)-Modified Amorphous Powder and Oxide Powders

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Journal of Rare Earths 2006年第Z2期24卷 263-265页

作者：史志铭 School of Materials Science and Engineering Inner Mongolia University of Technology

The cordierite ceramic with a high strength and a low thermal expansion coefficient was prepared by using mixtures of Ce4+-modified cordierite amorphous powder and oxide powders of MgO, Al2O3 and SiO2 as starting materials. The transformation procedure of the powders was analyzed by XRD method and the surface morphology of ceramics was examined by SEM method. The flexural strength was measured in a mechanical property testing machine using the Three-Point-Bending sample. Experimental results show that the ceramic added with 10%(mass fraction) of Ce4+-modified amorphous powder is composed of α-cordierite and small amount of CeO2 particles, and has a porosity of 15%(volume fraction) and a flexural strength of 32.6 MPa when sintered at 1350 ℃ for 3 h. It is suggested that this low-cost process is suitable for preparing the components such as supports of vehicle exhaust converters and diesel particulate trappers.

关键词： cordierite ceramic amorphous cerium thermal expansion density rare earths

Zeolite usage as source of silica to produce cordierite in MgO–Al_2O_3–SiO_2 system

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Journal of Advanced Ceramics 2018年第4期7卷 370-379页

作者： Tu?ba Tun? PARLAK A.?ükran DEMIRKIRAN Department of Metallurgical and Materials Engineering Faculty of EngineeringSakarya UniversityEsentepe Campus

In this study, natural zeolite was used as source of silica to produce cordierite. MgO and Al_2O_3 were added to zeolite to obtain the cordierite stoichiometry. Mixture of these raw materials was mechanically activated for different durations. The mechanically activated powder mixture was characterized using XRD, DSC, SEM, specific surface area, and particle size analyzer. The pycnometer method was used to measure the densities of mechanically activated powder mixtures. Mechanically activated for 60 min powder mixture was sintered at 1150–1350 ℃ for 1 h. The sintering behavior of the samples was determined by measuring the linear shrinkage, density, and apparent porosity. The phases in the sintered samples were identified by XRD. cordierite and spinel phases were detected for sintered at a temperature higher than 1150 ℃ but corundum accompanied to cordierite and spinel at 1150 ℃. The microstructure of the samples was examined using both SEM and AFM. The sintering behavior and microstructural properties of the samples changed with an increase in the sintering temperature. As the apparent porosity increased with increasing sintering temperature, linear shrinkage and density values decreased. Density values were determined as 2.31–2.69 g/cm^3 depending on the temperature. The grains coarsened at higher temperature and the average grain size depending on the temperature was 1.34–1.96 μm. From the results optimum sintering temperature was determined as 1250 ℃. Dense material was produced at a temperature as low as 1250 ℃ using zeolite as raw material.

关键词： mechanical activation sintering zeolite cordierite

Honeycomb-shaped Pt Sn Na/y-Al2O3/cordierite monolithic catalyst with improved stability and selectivity for propane dehydrogenation

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Chinese Chemical Letters 2018年第6期29卷 884-886页

作者： Shiyong Zhao Bolian Xu Lei Yu Yining Fan Key Laboratory of Mesoscopic Chemistry of Ministry of Education School of Chemistry and Chemical EngineeringNanjing University Nanjing 210093. China Nanjing University-Yangzhou Chemistry and Chemical Engineering Institute. Yangzhou 211400. China School of Chemistry and Chemical Engineering. Yangzhou University. Yangzhou 225002 China

novel honeycomb-shaped Pt Sn Na/g-Al2 O3/cordierite monolithic catalyst（Pt 0.5%, Sn 0.9%, Na 1.0%,relative to Al2 O3 weight） was developed and its catalytic performances in propane dehydrogenation were tested and compared with the classical granule catalyst with same Pt, Sn and Na contents under the conditions of 0.1 MPa, 590C, C3 H8/H2 at 3/1（molar ratio） and gas hourly space velocity（GHSV） at155 h-1. Interestingly, despite the generated coke amount and exposed Pt fraction, the honey combshaped structure of monolithic catalyst exerted important influences on its catalytic activities and led to the advanced catalytic performances over the granule catalyst.

关键词： Propane dehydrogenation Propylene Platinum cordierite Monolithic catalyst