The article is devoted to the study of the dependence of the change in compressive strength on temperature for refractory materials of the lining of a pouring ladle of ferroalloy production – fireclay bricks of the ShKU type. The thermographic analysis of the outer surface of the ladle and the condition of the inner surface of the lining showed that the main cause of cracking can be considered thermal stresses arising from significant temperature differences across the lining section during non-stationary thermal processes. The determining influence of thermal stresses on the destruction of the lining is confirmed by a visual examination of samples of refractory materials from the masonry. The experimental part contains a study of the dependence of the compressive strength on the temperature of new spent samples of refractories. Studies have shown that with increasing temperature, the value of the compressive strength increases in a certain temperature range. Thus, the maximum value of the ultimate compressive strength for new fireclay refractories is 44 % higher, and for partially exhausted refractories it is 56 % higher than the ultimate strength at a temperature of 20 ?C.
The results of the study of the chemical and mineralogical composition and the assessment of the suitability of magnesian raw materials, in particular serpentinites of Uzbekistan, taking into account the magnesian-silicate and magnesian-ferrous module for the production of refractory materials are presented. The results of determining the physical and mechanical properties of fired test samples at temperatures of 1000 and 1100 °C are presented. The suitability of using domestic serpentinites for the development of the composition of magnesia refractory materials has been established.
This study focuses on the sustainable utilization of shoushan stone mineral processing waste in glaze materials, exploring its synergistic effects on regulating the coloration mechanism and optimizing glaze layer performance. Through single-factor experiments, the impact of varying shoushan stone incorporation levels on ceramic properties was systematically analyzed. Techniques such as XRD, SEM, EDS, and XPS were employed to investigate the effects of shoushan stone on glaze layer structure, Cu ion valence states, and color performance. The results demonstrate that incorporating 10 wt. % shoushan stone significantly enhances the density and glossiness of the glaze layer, promotes the stable presence of Cu??, and induces phase separation structures, thereby improving the color purity and stability of blue glazes. Physicochemical performance tests indicate that the glaze layer exhibits excellent thermal shock resistance, mechanical strength, and environmental friendliness. The SiO?, Al?O?, K?O, and CaO abundant in shoushan stone provide superior fluxing and network regulation effects, confirming its feasibility as a blue glaze raw material. This study presents a novel approach to the high-value utilization of mineral waste, with significant theoretical and practical implications for the sustainable manufacturing of ceramic glazes.
The effect of the temperature of adhesive contact formation on the interphase boundary strength in the (Ge21Te79)100 – x(AgI)x glass–quartz glass systems has been studied. The values of the contact angles of wetting of quartz glass by (Ge21Te79)100 – x(AgI)x melts and the surface tension of chalcogenide glasses have been experimentally determined. The temperature dependences of the adhesion work of (Ge21Te79)100 – x(AgI)x melts to quartz glass have been studied. It has been established that the adhesive strength of the solid phase boundary correlates with the value of the adhesion work of the chalcogenide melt to the quartz glass surface. It has been shown that the adhesive strength of glasses (Ge21Te79)100 – x(AgI)x to quartz glass increases from 508 to 1104 kPa with an increase in the silver iodide content from 30 to 50 mol. %.
When comparing the optical characteristics of the obtained glasses in the UV region of the spectrum, it was shown that the glasses welded from KFK have greater transparency and higher transmission in the wavelength range of 190…1000 nm. The difference in the values of the light transmission coefficients is related both to the peculiarities of the technological schemes for glass production and to the trace element purity of the feedstock.
Experimental studies of the effect of laser radiation with a wavelength of 1.06 ?m on reaction-sintered silicon carbide-based ceramics in the range of power densities corresponding to the mode of advanced evaporation of the material have been conducted. The threshold value of the laser radiation power density and the power range corresponding to the minimum energy consumption during laser dimensional processing of reaction-sintered silicon carbide-based ceramics have been determined.
Presents the results of a study of PbZrO3 ceramics synthesized from nanodispersed PbO and ZrO2 powders with the addition of BaTiO3 nanoparticles with sizes of 50, 200 and 400 nm. It has been established that the addition of barium titanate BaTiO3 nanoparticles to lead zirconate PbZrO3-based ceramics promotes an expansion of the temperature range of the ferroelectric phase existence, right down to room temperature. With an increase in the BaTiO3 content, the maximum of the permittivity shifts to the region of lower temperatures, and the ?' values increase significantly, reaching a peak at a BaTiO3 concentration of 10 %, after which a decrease is observed.
A series of chromium-containing solid solutions CaCu3Ti4 – 4хСr4хO12 – ? (sp. gr. Im3) were obtained by the solid-phase synthesis method. The unit cell parameter of the solid solutions changed insignificantly from 7.3897 (х = 0.02) to 7.3866 ? (х = 0.06). Copper oxide was determined in the intergranular space in all samples. The samples were characterized by a low-porosity grain microstructure; with an increase in the chromium content in the samples from x = 0.01 to 0.06, the maximum longitudinal crystallite size, according to the scanning electron microscopy data, decreased from 16 to 10 ?m. Spectral studies of the charge state of chromium-doped titanium calcium copper CaCu3Ti4O12 cations were carried out using X-ray spectroscopy (XPS and NEXAFS). According to NEXAFS and XPS spectroscopy data, titanium cations have a charge state of +(4 – ?) in solid solutions of calcium-copper oxides, copper and calcium atoms have a charge state of +2, and doped chromium cations have a charge state of +3.
The chemical and mineralogical composition, grain structure and physicochemical properties of unenriched dune sands located in the Kushkupyr district of Uzbekistan were studied. Analysis of the granulometric composition indicates the predominance of particles with a size of at least 0.007 mm, while their fineness modulus does not exceed unity, which allows classifying these sands as fine-grained. Using scanning electron microscopy (SEM), the morphology of dune sand particles was studied and it was shown that its composition is mainly represented by irregularly shaped quartz grains. Compositions for obtaining sodium silicate in the microsilica – dune sand – caustic soda system are proposed.
The chemical and mineralogical compositions, physical and chemical characteristics and phase transformations of diabase rocks of the Uzunbulak deposit were studied. It has been shown that as a result of firing at a temperature of 1000 ?C, phase transformations occur in diabase samples, accompanied by the new formation of the minerals wollastonite, pyroxene and a small amount of high-temperature forms of quartz and cristobalite. The possibility of using this diabase rock as a raw material for producing acid-resistant materials for various purposes has been established.
