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Study of Phase Changes During Portland Clinker Firing
Pertlová, Alena ; Fridrichová, Marcela (referee) ; Gazdič, Dominik (advisor)
The presented bachelor thesis deals with monitoring of transformations during the burning of cement clinker. The theoretical part is devoted to the theories regarding the burning of Portland clinker and to the description of clinkers properties in general. The focus is put on the modern low-energy clinkers as well. Moreover, the thesis deals with several methods for determining the phase composition of cement clinker including HT-XRD analysis, which allows to monitor the behaviour of individual phases at high temperatures besides the determination of the phase composition. In the experimental part, there is introduced the project proposal of the model raw mixture used to produce ordinary Portland clinker and raw mixture of low-energy ternesite clinker. Furthermore, the thesis shows HT-XRD analysis done in the high temperature chamber, followed by the evaluation of results and their comparison with the theoretical background.
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Specification of the phase composition of Portland clinker
Vávrová, Alžběta ; Dlabajová, Lucie (referee) ; Másilko, Jiří (advisor)
This bachelor thesis deals with the determination of the phase composition of portland clinker and its optimization. The X-ray fluorescence spectroscopy, X-ray diffraction analysis and optical microscopy were used to solve this task. In the experimental section, X-ray fluorescence spectrometry results were used to calculate the potential phase composition of the clinker using the Bogue method. Then the X-ray diffraction analysis followed, it was used not only to determine the phase composition but also to determine amorphous content in the clinker. The microscope integration method was used to study the samples using optical microscopy. The obtained results were compared with each other and the main deficiencies of the individual methods were identified.
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Studying Formation and Kinetics of Belite Clinker Hydration
Halešová, Adéla ; Walter, Martin (referee) ; Gazdič, Dominik (advisor)
DIPLOMA THESIS IS DEVOTED TO THE STUDY OF PREPARATION OF PURE BELITE CLINKER FOR THE POTENTIAL INCREASE OF KINETICS OF THE HYDRATION PROCESS BY CHEMICAL ACTIVATION. THE THESIS OF THIS WORK IS BASED ON RESEARCH FINDINGS CONCERNING BELITE CLINKER AND RESEARCH AT THE INSTITUTE OF THD. THE THESIS AIMS TO DESIGN COMPOSITION OF THE RAW MEAL BURNING BELITE, FOLLOWING MODIFICATION BY SULPHATE AND POTASSIUM CARBONATE IN ORDER TO POTENTIALLY INCREASE THE REACTIVITY OF THE BURNT BELITE CLINKER AND THE LABORATORY FIRING OF PREPARED SAMPLES. THE LAST STEP WAS TO ASSESS THE MINERALOGICAL COMPOSITION OF BURNED SAMPLES XRD ANALYSIS AND FOLLOWING COMPARISON CELL PARAMETER OF BELITE WITH AND WITHOUT ADDED MODIFYING ADDITIVES.
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Application of Electron Backscatter Diffraction in Materials Engineering
Man, Ondřej ; Vodárek, Vlastimil (referee) ; Svoboda, Milan (referee) ; Švejcar, Jiří (advisor)
The thesis deals with principles and common applications of the electron backscatter diffraction (EBSD) method. Some practical experience in application of the method to a study of highly deformed structure of copper and its thermal stability is described on one hand, and, on the other hand, to a study of phase composition of TRIP steel on various levels of imposed strain. The limitations of EBSD method are discussed along with its resolution in comparison with other complimentary techniques.
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Relation between Preparation Parameters of Belite Cement and its Hydraulic Properties
Staněk, Theodor ; Palou, Martin (referee) ; Škvára, František (referee) ; Havlica, Jaromír (advisor)
The dissertation thesis is devoted to the study of belite clinkers and to the possibilities of the increase in their hydraulic activity. The mechanism and the kinetics of belite clinker formation were studied together with the relation of the velocity of these processes and the hydraulic activity of clinker. The influence of various parameters (degree of lime saturation, duration and temperature of burning) of the belite clinker preparation on the belite clinker development in time, on belite polymorphism, on the chemical composition of belite crystals and on the belite cement hydraulic activity was studied, too. The research methods used for the investigation involved electron microscopy, optical microscopy, X-ray diffraction analysis, high-temperature microphotometry and calorimetry. The resulting clinkers were hydraulically activated by addition of calcium sulfate. The experiments have proven that the higher rate of belite formation does not lead to the increase of its hydraulic activity, as opposed to that of alite. On the other hand, the chemical activation by sulfate anions enables to prepare clinker with relatively higher degree of lime saturation with minor admixture of alite and anhydrite, which is hydraulically activated. The work was concluded by experimental burning of belite clinker doped with sulfate anions in a model rotary kiln and by the preparation of cements blended with common industrial alite clinker. The results indicate the possibility of separate industrial production of special belite clinker alongside with common alite clinker and the production of economically and environmentally beneficial blended Portland cements with suitable technological parameters, or targeted production of special cements with properties corresponding to their required utilization.
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Analysis of Strain - induced Variations of Phase Composition of the TRIP Steel using EBSD Method
Pešina, Zbyněk ; Pantělejev, Libor (referee) ; Man, Ondřej (advisor)
The diploma thesis deals with phase composition measurement of the TRIP steel, using EBSD method. The steel was delivered as thermo-mechanically treated via two different routes. The phase composition of the steel was examined during gradual plastic deformation in the range 0 to10.99%. One route of thermo-mechanical treatment exhibited good agreement with the literature in terms of measured fraction of the retained austenite (15.6%) as well as its decrease during the deformation (to 8.9% at the maximum imposed strain). The samples of the second route did not show any agreement in either of the parameters spoken.
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Processing of Electroceramics from Nanopowders
Kachlík, Martin ; Trunec, Martin (referee) ; Maca, Karel (advisor)
Literature review of processing of bulk EuTiO3 ceramics was performed. Based on experiments performed the experimental conditions of solid-state reaction of Eu2O3 with Ti2O3, resp. TiO2 leading to single phase EuTiO3 were established. Balk EuTiO3 ceramics were prepared by means of cold isostatic pressing and sintering in reduction atmosphere. This ceramics is suitable for further evaluation of electromagnetic properties.
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Preparation and properties of nanocomposites based on Zr-Fe
Roupcová, Pavla ; Schneeweiss, Oldřich ; Bezdička, Petr
The spark erosion of the pure Zr and Fe electrodes in hydrogen yielded nanocrystalline powder consisting of the mixture of Zr-rich (Zr3FeH7, ZrO2, and Zr(Fe)) and Fe-rich phases with the mean chemical composition Zr-3.2wt.%Fe. Heat treatment in hydrogen atmosphere at 973K induced phase decomposition and transitions with the final composition of bcc Fe, Zr3Fe, ZrH2 and dominating ZrO2 phases. The result indicates that formation of Fe-rich phase (bcc Fe) embedded in ZrO2 could be possible using an appropriate heat treatment of the as-prepared powder.
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Preparation and properties of MgO-Ni(Fe) nanocrystalline composite
Schneeweiss, Oldřich ; Pizúrová, Naděžda ; Jirásková, Yvonna ; Žák, Tomáš ; Bezdička, Petr ; Večerníková, Eva
We have prepared MgO-Ni(Fe) nanocrystalline composites by controlled heat treatment of compacted spark synthesized nanocrystalline powders. Besides particle sizes and their chemical compositions, influence of interaction with surrounding atmosphere and adsorbed gases on phase composition and magnetic properties were investigated. Mössbauer spectroscopy, x-ray diffraction and TEM were used for phase analysis. Thermomagnetic curves and DTA/TG measurements were applied for detection of changes in structure and phase composition during heat treatments. The simultaneous gas analysis using mass spectroscopy by heating yielded information on adsorbed and dissolved gases and their reactions with the nanoparticles.
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