National Repository of Grey Literature 98 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Influence of Waste Diatomite as a Raw Material on the Properties of the Inorganic Foam Glass
Nguyen, Martin ; Sedlačík, Martin ; Sokolář, Radomír ; Opravil, Tomáš
This article deals with the manufacturing process of inorganic foam glass with utilization of waste diatomite as a raw material. The waste diatomite was first subjected to an analysis of chemical and mineralogical composition. The foam glass was formed by a powder sintering method by pressing into pellets with the addition of a foaming agent. After firing, the properties of the foam glass were investigated using an X-ray diffraction analysis, scanning electron microscopy, bulk density, and compressive strength. The possibility of utilization of waste diatomite in raw material mixtures was investigated in accordance with the influence of firing temperature and the resulting properties of inorganic foam glass.
Mapping the potential of secondary products from the production of titanium white
Nehéz, Samuel Emil ; Šoukal, František (referee) ; Opravil, Tomáš (advisor)
This bachelor’s thesis deals with the use of secondary products from the production of titanium white and its subsequent use during cement production. Secondary products from the production of TiO2 could be regarded as several kinds of sulphate waters, where by their successive neutralization gypsum by-products are prepared. The aim of the bachelor’s thesis was to experiment whether it is possible to use some of these gypsum by-products as solidification retarder in Portland cement. Cement pastes were prepared and subjected to mechanical and analytical examinations. During the mechanical examinations, strength in pressure during bending and strength in pulling for the duration of 60 days were monitored. The material from tested bodies of pastes was reviewed by x-ray difraction analysis after 7 and 28 days. Just as was determined the optimum W/C, initial and final setting time. The prepared samples with the gypsum by-product as their content had some features comparable with commercially used cement.
Possibilities of using waste diatomaceous earth
Jonešová, Markéta ; Másilko, Jiří (referee) ; Opravil, Tomáš (advisor)
Waste diatomaceous earth is a by-product generated during a production of diatomaceous earth for filtration. It is a material with very specific properties, which has currently no use other than backfilling of mining areas. For this reason, this Bachelor thesis deals with exploration of potential utilization possibilities of this remarkable material. Analysis of the waste diatomaceous earth will be carried out, and the chemical and physical properties will be determined. During experimental part, a set of calcination tests will be carried out and evaluated with focus on properties of the waste diatomaceous earth, which could be significantly increased by the calcination process. For example, a pozzolanic activity could be significantly affected.
Study of particles of various cosmetic pigments
Cerevatova, Kristina ; Opravil, Tomáš (referee) ; Zemanová, Jana (advisor)
The main focus areas of this master thesis include the writing of a literature review, which contains an overview and segregation of pigments which are used in the preparation of cosmetic products. The thesis is focused on the properties and characterization of pigments for use in cosmetology. The following focus is on legislation, more specifically on pigments that the cosmetic industry allows, limits and does not allow. The main part of this thesis is an overview of methods for the characterization of pigments. The practical part deals with the characterization of particles of selected cosmetic pigments by applying methods for determination of color, elemental and phase composition, particle size and morphology. The thesis is concluded by evaluation of the achieved results.
Monitoring of alkali-silica reaction
Doležal, Martin ; Kalina, Lukáš (referee) ; Opravil, Tomáš (advisor)
Due to the alkali-silica reaction (ASR), concrete structures are damaged, which can lead to the loss of their useful properties. For the reaction to take place, the presence of alkalis is required. During the work, the release of alkalis into the pore solution was monitored. During hydration pore solutions were taken, on the basis of calorimetric curves. In pore solutions the K+ a Na+ content was analyzed by ICP-OES. The result is graphs of the development of alkali content and their relationship to cement hydration. The danger of the alkali in tested samples for the course of the reaction is described here. The description of the alkali content and its development is important for understanding the course of ASR and proposing a viable solution to protect against this problem.
Monitoring of corrosion of refractory lining
Taraba, Vojtěch ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
This bachelor’s thesis is focused on the monitoring of corrosion of refractory lining in the cement rotary kiln, chemical and mineralogical changes of the refractory and their influence on the lining properties. Magnesia-spinel refractories located in the lower transition zone are analyzed by X-ray diffraction, X-ray fluorescence, inductively coupled plasma optical emission spectrometry and scanning electron microscopy.
Evaluation of properties of coal combustion solid residues
Cesnek, Ľuboš ; Bílek, Vlastimil (referee) ; Opravil, Tomáš (advisor)
The bachelor’s thesis focuses on condition monitoring of a stored high-temperature fly ash and its properties over time. The high-temperature fly ash comes from a dumping where it has been aggregated over several years. Samples of fly ash used for our analysis were taken from a bore-hole with a depth of 38 meters. Subsequently, detailed analyses of the fly ash from individual depth levels were performed. Furthermore, mechanical properties, volume stability and changes in weight of the prepared test beams were tested. The aim of the experiment was to evaluate suitability of using fly ash from a dumping site as a pozzolanic admixture in cement pastes.
Hybrid binders containing Portland clinker
Kratochvilová, Lucie ; Hrubý, Petr (referee) ; Opravil, Tomáš (advisor)
This bachelor thesis is focused on the use of cement kiln dust in combination with portland clinker. Cement kiln dust is a fine bulk material which is not good to mix further with cement, due to its unsuitable chemical composition. The aim of the bachelor thesis is to verify the possibilities of using this secondary material as a potential component of hybrid binders. For experimental part were taken several cement kiln dusts from different sources. The evaluation of the prepared binders was similar to Portland cement, the tests were performed according to ČSN EN 196.
Utilization of recycled brick waste for growing the agricultural plants
Šmírová, Barbora ; Másilko, Jiří (referee) ; Opravil, Tomáš (advisor)
The master thesis follows up on previous bachelor thesis, which dealt with the sorption capacity of brick recyclate. Brick recyclate, as same as brick, excel with very high porosity. For this reason this work deals with possible implementation of plant growth aids (fertilizers) on the inside surface of such highly porous material This thesis studies possibilities of preparation of brick recyclate with the content of components supporting plant growth. It is a material, that is able to bind water in the soil and nourish cultivated plants at the same time. Aim of the work is to find out, what maximum amount of supporting substances, that later will be released back into surrounding enviroment (soil), is possible to incorporate into the brick recyclate. Such prepared recyclate was added in different amounts into predefined substrates, where plants were grown. Subsequently, the growth course, germination and yields of selected crops were monitored. It was verified that the material based on recycled brick enriched with nutrients improves the distribution of nutrients in the soil and positively affects the germination, growth and yields of tested crops.
Inorganic thermal insulation material for masonry elements
Sedlačík, Martin ; Švec, Jiří (referee) ; Opravil, Tomáš (advisor)
This master’s thesis deals with preparation of foam glass and explores the possibilies of utilization of this material as an inorganic thermal insulating filler of fired hollow bricks. Foam glass was prepared via powder sintering method from waste packaging glass, using limestone and graphite as foaming agents. After inital analysis of raw materials, the effect of mixture composition and different processing parameters on bulk density, pore size and morphology of foam glass was investigated. Last but not least, different ways of manufacturing thermal insulating bricks, by preparation of foam glass directly in the cavities of fired hollow bricks, were tested.

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