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Kaoline whitness improvement by mechano-chemical treatment
Uher, Samuel ; Bartoníčková, Eva (referee) ; Šoukal, František (advisor)
The thesis deals with the issue of increasing the whiteness of kaolin by acid leaching simultaneously with milling. Kaolin was prepared from kaolin raw material from the Otovice quarry (Sedlecký kaolin a.s.), which was subsequently grined in suspension with oxalic acid, tartaric acid or citric acid in a ball planetary mill. We had been observing the influence of the type and concentration of acid and grinding time on many aspects, such as: the whiteness index, the amount of leached Fe and Ti, the distribution of Fe and Ti in kaolin, and the kaolin structure order.
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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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Optimization of kaoline flocculation process
Kurťák, Marek ; Švec, Jiří (referee) ; Šoukal, František (advisor)
The bachelor thesis deals with flocculation of Karlove Vary area kaolin raw materials, their sedimentation rate and correlation of the flocculation, and sedimentation properties with composition of a particular material. The research was composed of sedimentation rate monitoring, execution of COD test, and subjecting the materials emission spectrometry with inductively coupled plasma, ion chromatography and roentgen diffraction.
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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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Increasing the whiteness of kaoline
Bartošík, Jan ; Ptáček, Petr (referee) ; Šoukal, František (advisor)
The thesis deals with the issue of increasing the whiteness index of kaolin raw material. The research was focused on floating the kaolin suspension and the subsequent processes related to increasing the whiteness index. Increasing the whiteness of the kaolin raw material took place on the basis of acid leaching. The eluents were based on sulfuric acid, phosphoric acid, oxalic acid and sodium bisulfite. The leaching process was influenced by the temperature and concentration of the leaching agent. Floated and leached kaolin samples were characterized by several methods. The XRD method investigated the mineralogical composition and the kaolinite structure order. The distribution of chromogenic components was monitored by SEM-EDS. Residues of organic matter was determined by COD test and the concentration of chromogenic components in the extract was monitored by the ICP-OES method. Last but not least, the index of whiteness was measured, the increase of which is the aim of the diploma thesis, using a UV-VIS spectrometer with reflective extension.
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Thermophysical and electrical properties of illite-based ceramics
Csáki, Štefan ; Dobroň, Patrik (advisor) ; Koštial, Pavol (referee) ; Labaš, Vladimír (referee)
CSÁKI, Štefan: Thermophysical and electrical properties of illite-based ceramics. [Doctoral thesis]. Constantine the Philosopher University in Nitra. Faculty of Natural Sciences. Charles University. Faculty of Mathematics and Physics. Supervisor: prof. RNDr. Libor Vozár, CSc. (Constantine the Philosopher University in Nitra), doc. Ing. Patrik Dobroň, PhD. (Charles University). Nitra & Prague, 2018. 107 p. Illitic clays are of special importance in the ceramic industry. Therefore, a deep knowledge of the thermophysical processes, as well as the electric properties, is of special importance. The illitic clay originated in Northeastern Hungary was used in this thesis. The reactions, occurring during firing, were studied using thermal analyses (Differential thermal analysis, Thermogravimetry, Thermodilatometry) and special attention was paid to the measurement of the electrical conductivity (both DC and AC). Up to 250 řC, where the removal of the physically bond water (PBW) takes place, the dominant charge carriers were the H+ and OH- ions. After the PBW was removed, Na+ and K+ ions became the dominant charge carriers. During dehydroxylation (450 - 750 řC) H+ and OH- ions were freed from the illite structure, which supported the electrical conduction in the samples. At ~ 970 řC glassy phase appeared...
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Determination of hydraulic characteristcs of clay suspensions
Petrová, Markéta ; Mls, Jiří (advisor) ; Handová, Zdena (referee)
This thesis is focused on determining the hydromechanical characteristics of clay suspensions, permeability and compressibility, where is the effective stress, the concentration of suspension and is the permeability. Because the compressibility or permeability can't be measured directly, I use Darcian mechanics of two-phase systems to compute the characteristics I wanted from a well- measurable quantities, measured in appropriate experiments. Work has been solved with the support of the project : Hydromechanical characteristics of clay suspensions. The first part deals with a mineralogical characteristics fylosilicates, characterization of kaolin deposits in the Bohemian Massif, physical chemistry of colloidal systems, electric double layers and electro kinetic potential. Experimental section follows later, which proceed from the assumption that the same concentration of kaolin suspension and an identical colloidal state, exposed to the same pressure-temperature conditions, exhibit the same values of hydro mechanical characteristics such as their evolution in time can be described as a continuous function. As the model, I chose the coagulated kaolin suspension. Coagulation are achieved by adding weight percent of solids . Suspension settles in a vertical cylinder of high with an inner diameter of , which...
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Mechanical and thermophysical properties of illite-based ceramic materials.
Kušnír, Jakub ; Knapek, Michal (advisor) ; Chmelík, František (referee)
Title: Mechanical and thermophysical properties of illite-based ceramic materials. Author: Jakub Kušnír Department: Department of Physics of Materials Supervisor: RNDr. Michal Knapek, Ph.D, Department of Physics of Materials Abstract: This work examines high purity illite-based ceramic material (illite) with varying porosity, illite with fly-ash addition and textured illite- and kaolin-based ceramics. Investigated illitic clay originated from the Tokaj region in Hungary and contained 84 wt.% of illite. Kaolinitic clay (Sedlecký Kaolin Inc.) contained 88-94 wt.% of kaolinite. Samples were prepared using different heating regimes based on the type of material, with maximum firing temperature of 1100 řC. The porosity was controlled by adding charcoal powder to the green body before firing. Fly-ash waste from the combustion of powdered oil shale from Estonia was used as another additive. The microstructure of samples was analyzed by scanning electron microscopy. Mechanical properties were studied by compression tests with concurrent application of advanced investigation methods: Acoustic emission (AE) and Digital image correlation. By means of thermal analyses and AE we also investigated the frost resistance of samples with porosity created by charcoal combustion. Keywords: illite; kaolinite; ceramics;...
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Thermophysical and electrical properties of illite-based ceramics
Csáki, Štefan ; Dobroň, Patrik (advisor)
CSÁKI, Štefan: Thermophysical and electrical properties of illite-based ceramics. [Doctoral thesis]. Constantine the Philosopher University in Nitra. Faculty of Natural Sciences. Charles University. Faculty of Mathematics and Physics. Supervisor: prof. RNDr. Libor Vozár, CSc. (Constantine the Philosopher University in Nitra), doc. Ing. Patrik Dobroň, PhD. (Charles University). Nitra & Prague, 2018. 107 p. Illitic clays are of special importance in the ceramic industry. Therefore, a deep knowledge of the thermophysical processes, as well as the electric properties, is of special importance. The illitic clay originated in Northeastern Hungary was used in this thesis. The reactions, occurring during firing, were studied using thermal analyses (Differential thermal analysis, Thermogravimetry, Thermodilatometry) and special attention was paid to the measurement of the electrical conductivity (both DC and AC). Up to 250 řC, where the removal of the physically bond water (PBW) takes place, the dominant charge carriers were the H+ and OH- ions. After the PBW was removed, Na+ and K+ ions became the dominant charge carriers. During dehydroxylation (450 - 750 řC) H+ and OH- ions were freed from the illite structure, which supported the electrical conduction in the samples. At ~ 970 řC glassy phase appeared...
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Thermophysical and electrical properties of illite-based ceramics
Csáki, Štefan ; Dobroň, Patrik (advisor)
CSÁKI, Štefan: Thermophysical and electrical properties of illite-based ceramics. [Doctoral thesis]. Constantine the Philosopher University in Nitra. Faculty of Natural Sciences. Charles University. Faculty of Mathematics and Physics. Supervisor: prof. RNDr. Libor Vozár, CSc. (Constantine the Philosopher University in Nitra), doc. Ing. Patrik Dobroň, PhD. (Charles University). Nitra & Prague, 2018. 107 p. Illitic clays are of special importance in the ceramic industry. Therefore, a deep knowledge of the thermophysical processes, as well as the electric properties, is of special importance. The illitic clay originated in Northeastern Hungary was used in this thesis. The reactions, occurring during firing, were studied using thermal analyses (Differential thermal analysis, Thermogravimetry, Thermodilatometry) and special attention was paid to the measurement of the electrical conductivity (both DC and AC). Up to 250 řC, where the removal of the physically bond water (PBW) takes place, the dominant charge carriers were the H+ and OH- ions. After the PBW was removed, Na+ and K+ ions became the dominant charge carriers. During dehydroxylation (450 - 750 řC) H+ and OH- ions were freed from the illite structure, which supported the electrical conduction in the samples. At ~ 970 řC glassy phase appeared...
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