The possibilities of obtaining and producing a high-temperature silicate melt from quartz sand of the Tugan deposit (Tomsk region) using the energy of low-temperature plasma have been investigated.
The possibility of modifying natural zeolites with bismuth salts and their effect on electrical properties has been investigated. The absence of phase transitions at the melting point of bismuth was found.
A detailed consideration of the correlation relationship between the temperature coefficient of volumetric expansion (TCDC) o (T) ?-Al 2 O 3 of corundum and its heat capacity C (T) is carried out. It is shown that a clear correlation o (C) takes place not only in the low-temperature region (up to ~ 50 K), where it is linear (Gruneisen's law), but also in a wider temperature range, up to the melting point of corundum. A significant deviation from the low-temperature linear behavior of the temperature dependence TKOR o (C) occurs when the heat capacity reaches the classical 5 * 3R Dulong and Petit limit. The results of the work can be used to verify the data of primary calorimetric and dilatometric studies of ceramic and other materials.
Studies have shown that mullite crystallizes in the brick of the Kazan Kremlin in the form of primary ("flaky") mullite, pseudomorphs of glass with acicular mullite over feldspar, and pseudomorphs of glass with short-prismatic mullite. The M?ssbauer absorption spectra showed that, in the brick under study, hematite was found on the surface, and magnetite was found in the inner layer.
The results of studies on the possibility of using fiberglass plastics based on heterocyclic polymers and silica glass fabrics as heat-shielding materials are presented. Thermal, mechanical, thermophysical, radiotechnical and ablation properties have been determined in comparison with similar properties of traditional heat-shielding materials based on phenol-formaldehyde and organosilicon resins. It is shown that plastics based on heterocyclic polymers are of undoubted interest for the creation of new heat-shielding materials on their basis.
A mechanized technology for the production of large-sized fiberglass products by spraying has been developed. The technical feasibility and economic feasibility of using composite materials based on unsaturated polyester resins and glass roving for the production of large-sized items for various purposes using an accessible technology is shown.
The results of a theoretical study of the process of impregnation of glass fibers in the manufacture of highly filled composites by pultrusion are presented. The criterion is the maximum intensity of the technological process. An analytical study of the intensity depending on the main physical factors is proposed.
The main physicochemical characteristics of ceramic highly porous block-cell catalysts with a supported palladium active layer in the process of hydrogen oxidation under various experimental conditions are presented. Based on the data obtained on the activation energy and catalytic activity, a conclusion was drawn about the prospects of their application for the catalytic oxidation of hydrogen isotopes in comparison with imported granular catalysts.
Based on the compositions of the Y 2 O 3 - Al 2 O 3 - SiO 2 the sol-gel method synthesized protective thermostable coatings for silicon carbide materials, worked out the method of preparing sol-gel solutions, studied the effect of the ratio of the components in the initial solutions on the physicochemical properties of the solutions themselves and the gels obtained from them, studied the processes of phase formation during their heat treatment. The possibility of obtaining sintered materials with a wide range of ceramic properties is shown.
It was found that the low thermal stability of the industrial copper-containing catalyst from BASF is associated with the chemical looseness of the active component on the surface of the silica-earth support, and the deterioration of its strength properties occurs due to the phase transition of the SiO2 (?-quartz) support to ? - cristobalite. A thermostable copper-containing catalyst MAK-K with an active component tightly bound to an alumina-silica support has been proposed and investigated. Experimental tests of catalysts for thermal stability showed that at 350 ° C the relative activity of catalyst H3-11 decreases by 41%, while the relative activity of catalyst MAK-K changed by only 15%.
