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Possibilities of enhancement of kaolin whiteness
Krahulová, Veronika ; Bartoníčková, Eva (referee) ; Opravil, Tomáš (advisor)
This thesis focuses on problematics of increasing the kaolin whiteness index. The aim of the thesis is to verify possibilities and efficiency of the mechanical method of increasing whiteness of kaolin using sand of a defined fraction. This method cannot be considered as a whitening operation of kaolin but as a pre-treatment of the raw material or as one of the steps in increasing the whiteness. There have been tested diverse proportions of added sand with which the batch of kaolin material was intensively mixed for various times. Moreover, there has been tested influence of water and total batch volume. To characterize prepared samples there have been used several methods; XRF and XRD analysis was used to determine the elemental and phase composition of raw kaolin before and after mechanical sand action. The UV - VIS method with reflectance was used to assess the achieved whiteness.
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Possibilities of enhancement of kaolin whiteness by separation of components containing titanium
Vaculík, Josef ; Švec, Jiří (referee) ; Opravil, Tomáš (advisor)
Theme of the bachelor’s thesis is enhancement of kaolin whiteness primarily by removing titanium and iron. Titanium itself in the modification of anatase doesn’t decrease whiteness, more likely is the other way around. Unwanted modification is rutile, which is dark and it decreases substantially the whiteness of kaolin. The most significant impact on whiteness of kaolin has the iron (III) compounds that are usually contained with titanium in minor minerals in kaolin’s raw material. Main goal of thesis was to test the hydrothermal conditions on separation of parts containing titanium and iron from the kaolin’s material. Separation in the hydrothermal condition was performed by infusing kaolin in the solutions of acids of various concentrations. To find out the final whiteness of kaolin material after hydrothermal treatment was used UV-VIS method with reflective module and to find out the amount of iron and titan transferred to the solution of acids because of hydrothermal treatment was used ICP-OES method.
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Possibilities of application of phosphate bond in brick abrasion dust treatment
Tmejová, Jana ; Havlica, Jaromír (referee) ; Opravil, Tomáš (advisor)
This bachelor´s thesis deals with possibilities of application of phosphate bond in brick abrasion dust treatment. Brick abrasion dust is produced as a secondary product of brick production during brick grinding. Brick abrasion dust is a relatively fine powder of the same composition as a burnt brick fragment. Since the brick abrasion contains an insufficient amount of the aluminum component, which is crucial for the formation of phosphate bond, the work is primarily concerned with finding a suitable aluminum dopant. The aim of the thesis is to find a suitable admixture that has a sufficient content of aluminum to form a phosphate bond and to determine the ideal amount to be added. Alternative sources of the aluminum component are tested in combination with a commercially available phosphate bond (Alufos 50).
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Monitoring of alkalis in Portland clinker
Siudová, Alena ; Šoukal, František (referee) ; Opravil, Tomáš (advisor)
This bachelor thesis focuses on the localization of alkali in Portland clinker and their properties, which can significantly affect the lifetime of the concrete produced from these cements. The bachelor thesis deals with the study of the phases of the alkali in Portland clinker and the compounds they represent. Further, the bachelor thesis deals with the study of the rate of transfer of alkali into solution when mixing Portland clinker with water. Several different Portland slinks are analyzed and compared. The aim of the thesis is to try to find a connection between measured experimental values, clinker composition and alkaline-silica reaction precursors.
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Possibilities of separation of phosphorus compounds from sewage sludge
Iliushchenko, Valeriia ; Kalina, Lukáš (referee) ; Opravil, Tomáš (advisor)
This bachelor work deals with the issue of non-renewable natural resource – phosphorus. Phosphorus finds its application especially in the form of the salts of phosphorous acid. The use of phosphorus compounds is very varied from binders for refractory materials, fertilizer to foodstuffs. Due to the fact, that relatively large amount of human activity is bounded with phosphorus and its compounds, it can be assumed that over the time, the amount of phosphorus respectively its compounds will decrease, so the cost will increase. Owing to widespread use of this stuffs, it can be supposed that these substances could be concentrated for example in sewage sludge. Therefore, the object of this study will be the treatment of sewage sludge, where methods for separating phosphorus compounds will be sought. The aim of this bachelor work is to verify, whether sewage sludge can be used as an alternative source of phosphorus.
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Ash – the raw material base for the future
Marko, Michal ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
This master’s thesis responds to the worldwide problem concerning in the search of new material base for the future usage. Solid residues from high temperature or fluid coal combustion could be one of many alternatives to the raw materials. The study deals with the analysis of side energy products produced by power plant industry in the Czech Republic. Based on the fly ash chemical composition, possibilities of aluminium and even iron and titanium separation were proposed and then proved in the laboratory scale. Extracted components were separated selectively using apropriate methods. Then a couple of sintering reactions leading to improvement the leachability of selected elements from the fly ash matrix were carried out. Appropriate input material modification by high-temperature sintering reaction combined with extraction process in the sulfuric acid solution leads in dissolution up to 99 % of aluminium from the fluid and high-temperature fly ash.
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Possibilities of affecting the portland cement hydration by the addition of fluidized ash
Nehybka, Josef ; Bartoníčková, Eva (referee) ; Opravil, Tomáš (advisor)
This work is focused on study of possibilities of influence of hydration of Portland cement with an admixture of fluid ashes. The work deals with the tests with fluid filter ashes and milled fluid bed combustion ashes. Predominantly, a calorimetric measurement is used for study of admixtures. The prepared samples were found out on their mechanical parameters as the tensile bending strength and compressive stress. X-ray powder diffraction was used to determine of phase composition of the raw materials and created samples after hydration.
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Possibilities of application of meta-talc
Fridrich, Jakub ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
The aim of this bachelor thesis is study of physical and chemical properties of metatalk. Metatalc is delaminated and dehydroxylated form of talc which was earlier prepared and described on FCH BUT in cooperation with MRC (Material Research Center). This thesis is part of the way to find suiting use for this newly found material and it takes on proposing forms of use. Tested attributes are particle size, particle surface, volumetric mass, sorption and cation exchange capacity.
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Possibilities of utilization of brick-grind-dust in alternative binding systems based on fluidized ash
Tušla, Václav ; Švec, Jiří (referee) ; Opravil, Tomáš (advisor)
This bachelor´s thesis deals with usage of brick-grind-dust in alternative binding systems based on ashes of fluid combustion. Specifically it deals with fly ashes and softly milled bed ashes of brown coal combustion. Primarily thanks of content of free lime, anhydrite and other components, fluid ashes have binding properities. Brick-grind-dust arise in end formation of burned bricks. The aim of thesis is to verify, possibilities to create composite of appropriate abilities with high or even exclusive amount of fluid ashes and brick-grind-waste. The paper also deals with influence of some chemical modifying additive on this alternative systems.
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Possibilities of application of fluidized bed combustion solid residues from municipal waste
Melicher, Daniel ; Solný, Tomáš (referee) ; Opravil, Tomáš (advisor)
The bachelor thesis deals with the use of solid residues from incineration waste products, especially in the construction industry. The aim of the thesis is to test various modifications of solid residues from incineration waste. These secondary materials were tested in bonding systems based on hydratation of portland cement, gypsum made from chemogypsum, quicklime and alkali-activated systems. The aim was to verify whether solid residues from waste incineration could be used as a component of alternative materials for the construction industry.
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