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Effect of Microwave Heating on Infrared Radiation Properties of cordierite-Ferrites Based Composite Ceramics

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Journal of the Chinese Ceramic Society 2015年第1期 38-43页

作者： LU Lei FAN Xi'an HU Xiaoming ZHANG Jianyi The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and Technology Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and Technology Suzhou Sagreon New Materials Co. LTD.

The cordierite-ferrites based infrared radiation composite materials were synthesized with Fe2O3, Mn O2, Cu O, Co2O3, and Mg2Al4Si5O18 powders as raw materials via microwave heating. The cordierite-ferrites based composite ceramics could be obtained via microwave heating at 1173 K for 1 h or 1473 K for 10 min, respectively. The lower synthesis temperature or the shorter heating time results in the smaller grain size of the composite ceramics obtained by microwave heating. The interplanar distance of cordierite becomes greater after microwave heating, indicating that the doping effect of transitional metal oxides on the cordierite is more efficient in microwave heating. The infrared radiation composite ceramics synthesized by microwave heating at 1473 K for 1 h exhibit the maximum emissivity of 0.9 in the band range of 6-8 μm at 1073 K.

关键词： infrared emissivity spinel cordierite microwave heating energy-saving

Determination Method of Thermal Expansion Coefficient of cordierite

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China's Refractories 2013年第4期22卷 14-17页

作者： YANG Daoyuan ZHU Kai WU Juan School of Materials Science and Engineering Zhengzhou University Henan Province Product Quality Supervision and Inspection Center

cordierite ceramics were prepared by using talc, bauxite and kaolin clay as starting materials. According to the detected resuh of XRD step-scanning from 25° to 35° by a high temperature X-ray diffractometer, 20 and d values of five peaks of cordierite crystal were ascer- rained. Then the least squares technique was used to cal- culate the crystal parameters ： at 25 ℃ , a = b = O. 981 8 nm, c =0. 927 4 nm, V=O. 774 3 nm3 ; at 600 ℃ , a =b =O. 982 0 nm, c=0.9252 nm, V=O. 773 5 nm3. The crystal volumetric coefficient of thermal expansion （CTE） and linear CTE along a and c axes were calcu- lated, αv = 2. 33 × 10-6℃-1, αa = αb, = 3. 27 × 10-6℃ -1 , αc = -4.19 ×10-6℃ -1. The average CTE of cordierite crystal is as low as O. 78 × 10-6℃ -1

关键词： cordierite thermal expansion coefficient calculation method high temperature XRD

Research on application of different particle sizes of cordierite on castable refractory

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Engineering Sciences 2012年第1期10卷 72-75页

作者： Zhang Wei Dai Wenyong Nobuaki Chiyoda Plibrico(Dalian)Industries Co. LtdDalianLiaoning 116600China

Effect of different particle sizes of cordierite on properties of castable refractory by different heat treatment temperatures were investigated respectively with mullite and bauxite as raw materials, calcium aluminate cement as binders. After 24 h curing in mould and another 24 h curing at 110 ℃ after demoulding, the specimens were heat treated at 1 000 ℃, 1 300℃ and 1 500℃ for 3 h, respectively. The bulk density （ BD）, permanent linear change （ PLC）, modulus of rupture（MOR） and clod crushing strength（CCS）, thermal expansion coefficient and thermal shock resistance were examined. The results show that there is no obvious effect on adjusting permanent linear change and bulk density of castables by adding different particle sizes of cordierite at low temperature and intermediate temperature. Modulus of rupture of castable increase with the decreasing of the particle sizes of cordierite after heat treated by 1 000 ℃ and 1 300℃. In this experiment, thermal shock resistance of the castable with cordierite whose particle size is 0 - 1 mm is the best.

关键词： cordierite particle size castable refractory heat treatment temperatures thermal shock resistance

In-situ Synthesis of Cu-SAPO-34/cordierite with Ultrasonic Treatment and Its Property of NOx Removal

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In-situ Synthesis of Cu-SAPO-34/Cordierite with Ultrasonic T...

Distribution of Cerium Ion in cordierite Ceramics and Its Effect on Structure of cordierite Crystal

中国材料大会2012

作者： Zhijuan Gao Weiren Bao Liping Chang Jiancheng Wang Key Laboratory of Coal Science and Technology Ministry of Education and Shanxi Province Taiyuan University of Technology

ISBN: (纸本)9783037856062;3037856068

A Cu-SAPO-34/cordierite monolithic catalyst was prepared by in-situ hydrothermal method. The effects of ultrasonic treatment were mainly investigated during the preparing process. The removal of NOX was evaluated using a fixed-bed reactor. X-ray diffraction, scanning electron microscopy were used to characterize the samples showing that the crystallinity of Cu-SAPO-34 molecular sieve have increased after ultrasonic treatment. The Cu-SAPO-34/cordierite prepared by ultrasonic treatment showed higher de-NOx activity and stronger anti-aging property. NOx conversion could reach more than 80% between 440 and 560 ℃ over the fresh Cu-SAPO-34/cordierite catalyst with ultrasonic treatment （600 W, 2 h） and the highest conversion was 86%, however, the highest conversion was only 76% over the Cu-SAPO-34/cordierite catalyst without ultrasonic treatment. After aging （treated for 15 h at 720 ℃ in the presence of 200 ppm SO2 and 10% vapor）, NOx conversion reached more than 45% between 400 and 520 ℃ over the catalyst with ultrasonic treatment and the highest conversion was 57%, however, the highest conversion was only 43% over the catalyst without ultrasonic treatment. The XRD and SEM results indicated that the structure and morphology of Cu-SAPO-34/cordierite monolithic catalyst kept in good condition after aging.

关键词： Ultrasonic Cu-SAPO-34 cordierite NOx SCR.

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Distribution of Cerium Ion in Cordierite Ceramics and Its Ef...

Development And Characterization of Ultra Low Cement Castable cordierites by Thixotropic Properties Mixtures

2004 International Conference on Rare Earth Ceramics and Glass

作者：史志铭 School of Materials Science and Engineering Inner Mongolia University of TechnologyHohhot 010062China

＜正＞ Cerium addition plays an important role in sintering, transformation and phasicochemical properties of cordi-erite ceramics. The present work aims at studying the distribution of Ce4+ in cordierite ceramics and its effect on the structure of cordierite crystal by means of differential thermal analysis （DTA）, X-ray diffraction （XRD） and scanning electronic microscope （SEM） so as to clarify the behavior of Ce4+. Results show that Ce4+ can exist in two forms of CeO2 particles and solid solution in Ce4 + -modified cordierite ceramics by the sol-gel method. The CeO2 particles separately distribute in the cordierite matrix. Ce4+ dissolves little into cordierite crystal, resulting in a decrease of lattice constants of the crystal. This kind of distribution behavior of Ce4+ makes us to easily tailor the properties of the cordierite ceramics.

关键词： cerium CeO2 cordierite rare earths

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Advances in Materials Physics and Chemistry 2012年第4期2卷 96-98页

作者： Ana M. Paniagua-Mercado Arturo Méndez-Sánchez Elvia Díaz Valdés Concepción Mejía García Depto. de Física Escuela Superior de Física y Matemáticas Instituto Politécnico Nacional Col. Lindavista CP 03778 México D. F. México

The main target in this investigation was to take advantage of the reology properties of the tixotropic mixes in Ultra Low Cement Castables (ULCC). The cordierite phase in refractory mix can be obtained using raw materials with magnesium oxide in its composition, such as, Mg(OH)2 or H2Mg3(SiO3)4 (Talc mineral), with a content of? 63.5% SiO2, 31.7% MgO and 4.8% H2O. In this investigation, as magnesium source, a commercial calcined magnesite with 90% MgO was used.? This mineral was selected instead of Talc mineral, because this last contains more impurities in its composition that tend to form more amounts of liquid phases with low fusion points. For this work two different ULCC mixes were designed. These were fired at 1260 oC, the cordierite phase was quantified in each mix.

关键词： Reology Thixotropic Mixtures Ultra Low Cement Castables cordierite

MICROSTRUCTURE AND INFRARED EMISSIVITY AT NORMAL TEMPERATURE IN TRANSITIONAL METAL OXIDES SYSTEM CERAMICS

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Journal of Wuhan University of Technology(Materials Science) 2000年第2期15卷 15-20页

作者：徐庆 Wuhan University of Technology China State Key Lab. Adv. Technol. Mat. S. Sch. of Mat. Science and Engineering Wuhan University of Technology Wuhan 430070 China

The fabrication of Fe2O3-MnO2-Co2O3-CuO system ceramics, and the composite system ceramics of transitional metal oxides-cordierite and transitional metal oxides-kaolinit are presented in this work. The research was carried out with the main attention to the infrared emissivity in the band of 8 similar to 14 mu m at room temperature, the microstructure of the ceramics and the relation between them. High infrared emissivities exceeding 0.9 in the band of 8 similar to 14 mu m at room temperature were gained in the transitional metal oxide ceramics and the composite system ceramics. It is suggested that the formation of inverse spinels and partially inverse spinels, such as Fe3O4, CoFe2O4, CuFe2O4 and CuMn2O4, is beneficial to the enhancement of the infrared emissivity of the transitional metal oxide ceramics. The transitional metal oxides play an important role in determining the infrared emissivity of the composite system ceramics.

关键词： transitional metal oxide cordierite kaolinite infrared radiation ceramics room temperature

Synthesis of Al2O3-SiO2-MgO ceramics with hierarchical porous structure

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Journal of Advanced Ceramics 2017年第1期6卷 92-页

作者： Elena F.KRIVOSHAPKINA Pavel V.KRIVOSHAPKIN Aleksey A.VEDYAGIN Institute of Chemistry of Komi SC UB RAS Syktyvkar 167982 Russia ITMO University St.Petersburg 197101 Russia Boreskov Institute of Catalysis SB RAS Novosibirsk 630090 Russia National Research Tomsk Polytechnic University Tomsk 634050 Russia

A series of asymmetric cordierite ceramics with hierarchical porous structure were prepared and *** macroporous support was obtained from natural raw materials (bauxite,silica sand,kaolinite,talc,and alumina) via ceramic *** prepared ceramic discs were characterized by a narrow pore size *** average pore size was about 9.5 μm,and the open porosity was estimated to be 30％.Coating the discs with micro/mesoporous cordierite layer was performed using the sol-gel ***-component sols were obtained from organic or inorganic *** gels were calcined at 1200 ℃ to form the cordierite *** nature of precursor was found to affect the pore volume *** pore volume distribution was observed when organic precursors were *** key factor to control the parameters of final material was the drying *** drying of the gels has allowed us to increase the surface area in two orders of magnitude comparing with conventional drying procedure.

关键词： sol-gel method aerogels cordierite Al2O3-SiO2-MgO hierarchical porous structure

Effects of regenerative mechanical vibration on the mechanical integrity of ceramic diesel particulate filters

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Journal of Advanced Ceramics 2018年第1期7卷 5-16页

作者： Gbadebo OWOLABI Akindele ODESHI Paul RAGALLER AlexANDer SAPPOK Department of Mechanical Engineering Howard University Department of Mechanical Engineering University of Saskatchewan CTS Corporation Boston Innovation Office

In this study, the effects of mechanical vibration on the mechanical properties of ceramic diesel particulate filters(DPFs) were investigated. The goal is to determine how the mechanical vibration used in the regenerative ash cleaning process for these filters affects their mechanical integrity during subsequent reuse. Both virgin and vibrated DPF samples were subjected to compressive and 3-point flexural loading at three different loading rates along axial and tangential directions. Statistical analysis was conducted to determine the significance of variation in the compressive and flexural strengths of the DPFs as a result of exposure to mechanical vibration. The results show that there is no statistically significant difference in both compressive and flexural strengths of the virgin DPFs and the DPFs subjected to the same level of mechanical vibration typically used in ash cleaning of DPFs. When the intensity of vibration was doubled, the drop in compressive strength became statistically significant, but less than 10% under axial loading. However, no drop in flexural strength was observed for DPFs subjected to this high intensity of mechanical vibration. The safe threshold for mechanical vibration of ceramic filters is considered to be much higher than that currently used in vibration-based ash cleaning process.

关键词： diesel particulate filter(DPF) cordierite mechanical testing filter regeneration vibration based ash cleaning technology