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ON THE DECOMPOSITION OF ALITE IN PORTLAND cement clinker

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Journal of Wuhan University of Technology(Materials Science) 1998年第2期13卷 26-31页

作者：刘顺妮 Wuhan University of Technology China Coll. of Mat. Science and Technology Wuhan Univ. of Tech. Wuhan 430070 China

The decomposition speed and mechanism of alite in Portland cement clinker are studied by means of optical microscopy, EPMA, XRD and chemical analysis. The results show that alite in portland cement clinker decomposes at the maximum speed when the temperature is at 1025 to approximately 1175 degree C. It takes about 40 hours for the alite in clinker burnt in the rotary kiln to completely decompose at 1175 degree C, and about 68 hours for the alite burnt in RSP-kiln. The presence of CaF//2 or CaSO//4 greatly affects the decomposition speed of alite. The former resists alite to decompose but the latter accelerates it and enables alite to decompose completely within 6 hours or less. (Author abstract) 3 Refs.

关键词： decomposition of alite cement clinker decomposition mechanism

Composition Design for High C_3S cement clinker and Its Mineral Formation

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Journal of Wuhan University of Technology(Materials Science) 2007年第1期22卷 56-60页

作者：侯贵华 College of Material Science and Engineering Nanjing University of Technology Center of Physical Testing and Chemical Analysis Yancheng Institute of Technology Yancheng 224003 China

A new composition of Portland cement clinker was studied, in which KH, SM and IM was 0.98,2.4 and 2.4 respectively as well as its meal added 1%CuO （in mass）. Fired at 1 200℃,1 350℃,1 400℃ and 1 450℃ for 30 min, the resultant mineral phases component and mineral morphology were analyzed. The performances of the cement which was made of clinker burned at 1 450℃ and fly ash were determined. By means of QXRD, XRD and optical microscopy, it is shown that the clinker burnt at 1 450℃ has the larger size crystals and distinct crystal interface, in which the C3S content is 73.37% and the mineral phases is dominantly C3S, following by minor C2S, C3A and tetracalcium aluminoferrite. The results reveal that a new type of high C3S content clinker can completely be made by traditional temperature-time schedule. The performances of the cement produced from this clinker with addtion of 50% fly ash and 5% gupsum were in agreement with the 32.5 strength grade of Portland fly-ash cement. The results also show that the clinker has a significant effect of saving energy and utilizing waste slag.

关键词： tricalcium silicate fly ash cement clinker copper oxide

Effect of CuO on the Burnability and Mineral Formation of High C_3S cement clinker

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Journal of Wuhan University of Technology(Materials Science) 2010年第5期25卷 838-844页

作者：陈胡星马先伟 Material Science and Engineering College Zhejiang University Laboratory of Concrete Material Research Tongji University Henan Universities of Urban Construction

The effect of CuO on the clinkering process and mineral structure, components and morphology of high C3S cement clinker was studied. One reference mixture was prepared according to the potential mineral phase components C3S=75%, C3A=7%, C4AF=18% and then was mixed, respectively, with 0.5%, 1%, 1.5%, 2%, 2.5% and 4% CuO. All samples were heated at a rate of 10°C/min to the design temperatures and then maintained for 40 min. Analyses by the glycerol-ethanol method, XRD and SEM-EDS show that the minimum of free lime （f-CaO） content was related to temperature and CuO amount. The higher the temperature, the lower the amount of CuO corresponding to the f-CaO minimum content. CuO promotes the formation and growth of C3S and C4AF and a new compound is found. In addition, these phenomena are discussed theoretically. In conclusion, CuO alters the burnability and the formation and structure of C3S in a high C3S cement system.

关键词： CuO tricalcium silicate burnability cement clinker mineral formation

Prediction of Free Lime Content in cement clinker Based on RBF Neural Network

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Journal of Wuhan University of Technology(Materials Science) 2012年第1期27卷 187-190页

作者： YUAN Jingling ZHONG Luo DU nongfu TAO Haizheng School of Computer Science and Technology Wuhan University of Technology State Key Laboratory of Silicate Materials for Architecture(Wuhan University of Technology)

Considering the fact that free calcium oxide content is an important parameter to evaluate the quality of cement clinker, it is very significant to predict the change of free calcium oxide content through adjusting the parameters of processing technique. In fact, the making process of cement clinker is very complex. Therefore, it is very difficult to describe this relationship using the conventional mathematical methods. Using several models, i e, linear regression model, nonlinear regression model, Back Propagation neural network model, and Radial Basis Function （RBF） neural network model, we investigated the possibility to predict the free calcium oxide content according to selected parameters of the production process. The results indicate that RBF neural network model can predict the free lime content with the highest precision （1.3%） among all the models.

关键词： RBF neural network cement clinker free lime content

Measurement of Monochromatic Emissivity of cement clinker with Various Fe_2O_3 Content at High Temperature

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Journal of Thermal Science 1996年第2期5卷 128-131页

作者： Z.J. Ye C.F. Ma S.Y. Huang(Beijing Polytechnic University, Beijing 100022, China) Beijing Polytechnic University Beijing China

An application of the optical pyrometer is studied for measuring monochromatic emissivities of cement clinker with various Fe2O3 *** idea of using “brightness temperature”is introduced into the emissivity measurement. In this method, there is no need for measuring an actual temperature of sample surfaces, only with determining both brightness temperatures of a sample and a blackbody can the required emissivity be evaluated according to Wien’s radiation law. In practice, the cement clinker is regarded as a greybody, the monochromatic emissivity is approximately equal to the total emissivity, so a single-colour optical pyrometer is applied for this purpose. Test measurements are carried out on 10 kinds of cement clinkers. Experimental data are treated by the least square method. As a result, the emissivity variation with temperature at a certain Fe2O3 content is quite well represented by εn=α+bT. Furthermore, this work first reported that the emissivities of cement clinker change considerably with Fe2O3 contents. In multiple cement production this conclusion is very important.

关键词： monochromatic emissivity brightness temperature cement clinker blackbody radiation

Catalytic performance of cement clinker supported nickel catalyst in glycerol dry reforming

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Journal of Energy Chemistry 2014年第5期23卷 645-656页

作者： Hua Chyn Lee Kah Weng Siew Maksudur R.Khan Sim Yee Chin Jolius Gimbun Chin Kui Cheng Faculty of Chemical & Natural Resources Engineering Universiti Malaysia Pahang Lebuhraya Tun Razak 26300 Gambang Kuantan Pahang Malaysia Centre of Excellence for Advanced Research in Fluid Flow Universiti Malaysia Pahang Lebuhraya Tun Razak 26300 Gambang Kuantan Pahang Malaysia

The paper reports the development of cement clinker-supported nickel （with metal loadings of 5 wt%, 10 wt%, 15 wt% and 20 wt%） catalysts for glycerol dry （CO2） reforming reaction. XRF results showed that CaO constituted 62.0% of cement clinker. The physicochemical characterization of the catalysts revealed 32-folds increment of BET surface area （SBET） with the addition of nickel metal into the cement clinker, which was also corroborated by FESEM images. Significantly, XRD results suggested different types of Ni oxides formation with Ni loading, whilst Ca3SiO5 and Ca2Al0.67Mn0.33FeO5 were the main crystallite species for pure cement clinker. Temperature-programmed reduction analysis yielded three domains of H2 reduction peaks, viz. centered at approximately 750 K referred to as type-Ⅰ peaks, another peaks at 820 K denoted as type-Ⅱ peaks and the highest reduction peaks, type-Ⅲ recorded at above 1000 K. 20 wt% Ni was found to be the best loading with the highest XG and H2 yield, whilst the lowest methanation activity. Syngas with lower H2/CO ratios （0.6 to 1.5） were readily produced from glycerol dry reforming at CO2-to-Glycerol feed ratio （CGR） of unity. Nonetheless, carbon deposit comprised of whisker type （Cv） and graphitic-like type （Cc） species were found to be in majority on 20 wt%Ni/CC catalysts.

关键词： cement clinker dry reforming glycerol nickel catalyst syngas

THE FORMATION MECHANISM OF PORTLAND cement clinker MINERALS IN RAPID BURNING

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Journal of Wuhan University of Technology(Materials Science) 1992年第3期7卷 26-34页

作者：胡曙光 Department of Material Engineering Wuhan University of Technology

cement clinker is burnt at the rapid heating rate has the obvious effect of saving energy due to the low burning temperature and short burning time. This kind of technique is being researched actively in recent years, but the systematical theory investigation about the formation mechanism of clinker minerals under this condition has not been reported. In this paper, the formation mechanism of Portland cement clinker minerals in rapid burning was studied by means of DTA, SEM, EPMA, XRD and other conventional testing methods by using a special burning equipment.

关键词： rapid burning fast heating technique formation mechanism cement clinker

A STUDY ON THE KINETICS AND SOME MECHANISMS OF cement clinker FORMATION

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Journal of Wuhan University of Technology(Materials Science) 1989年第1期4卷 1-11页

作者：冯其璜张文敬禹尚仁

In this paper for saving energy two different burning methods of cement clinker formation have been *** is the rapid burning method and the other is ordinary burning method simulating rotary kiln,and they are compared by the kinetic point of *** result reveals that the activation energy of rapid burning is much lower than ordinary *** looking into the cause, the main raw material—lime stone was burnt by the same two methods and the structure of product CaO has been *** can be found that the microstructure of CaO produced by rapid burning is looser;lattices constants are greater;crystal defects are more and particle size is smaller than that produced by ordinary *** cause the chemical reaction more *** the activation energy of clinker formation of rapid burning is much lower than that of the ordinary burning.

关键词： Burning cement clinker Kinetics

Adherence Characteristics of cement clinker on Basic Bricks

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China's Refractories 2002年第4期11卷 9-16页

作者： Michel Rigaud Ecole Polytechnique University of Montreal 8475 Christophe-Colomb Montreal Quebec Canada H2M 2N9

Based on the sandwich test, adherence mechanisms of cement clinker on various basic bricks were tackled by microstructural observations with help of cathodolumi-nescence technique. Doloma based bricks offer sufficient lime to react with clinker, forming C3S rich layer and initializing superior adherence. However, clinker with low silica ratio leads to MgO agglomeration at the interface of doloma bricks, which reduces adherence strength. On magnesia spinel bricks , fine, crystalline spinel easily reacts with lime containing phases from clinker to form low-melting phases and belite zone, which shows high adherence performance. Lack of fine spinel in magnesia spinel bricks results in poor adherence.

关键词： Basic brick cement clinker cement rotary kiln Adherence mechanism