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The processes of powder production of CeO2 by reverse deposition are investigated. The CeO2 content in the resulting products is 99.2 % by weight. The main phase is cerium dioxide with a cubic lattice. The average particle size of the powder is ?42 microns, and the specific surface area is ?38.6 m2/g. A mass loss of 18 % occurs as a result of heating the material from 50 to 1200 °C. This mass loss is accompanied by endothermic effects with peaks on the DTA curve at temperatures of 144, 280 and 374 °C. The possibility of upgrading the properties of the resulting powder, in particular morphology, and determining the area of the most suitable application may become the topic of further research.
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The paper presents the results of a study on the development of a primer-free enamel frit with increased chemical resistance to acids and alkalis, designed to protect steel pipelines. Zinc oxide was introduced into the composition of the frit, which helps to increase the resistance due to the higher chemical bond energy of the ion with oxygen compared with alkali metal ions. At the same time, the ZnO content is up to 10 wt. % reduces the frit's flow temperature. The experimental frit meets the standard requirements for spreading capacity (45 mm) and coefficient of thermal expansion (112?10–7 K–1). The introduction of zinc oxide in the amount of 5 wt. % in industrial borosilicate enamel leads to an increase in its chemical resistance by 4 times to acids and 8 times to alkalis compared to traditional industrial frit.
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The article presents the successful project of the BDTR-500 robot, designed for diagnosing cracks in pipes with a silicate-enameled coating. Key achievements of the system include the use of GPS navigation and positioning methods that ensure precise location determination and rapid identification of emergency zones. New algorithms based on artificial intelligence and machine learning facilitate autonomous robot movement and high-quality data processing. High-megapixel cameras with a smart lighting system allow for effective visualization of defects, while the intelligent energy management system increases the operational time in autonomous mode. Real-time data processing ensures rapid localization and elimination of damages, while built-in sensors enhance image stability on uneven surfaces. The robot can detect cracks as small as 0.1 meters. The project results confirm the high efficiency of the BDTR-500 in diagnostics, opening new opportunities for the application of technologies in monitoring the condition of pipelines and in other challenging operating environments.
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Through comprehensive studies of the chemical and mineralogical composition and technological properties of the wastes of ceramic production of “Kulol” JSC in order to be able to use them as a component of the raw mixture for the production of Portland cement clinker, it has been established that the complete or partial replacement of natural clay raw materials – loess in the composition of raw mixtures with waste from ceramic production increases their reactivity during firing, accelerates the process of assimilation of CaOfree and contributes to the completion of the process of mineral formation with good granulation of clinkers at a relatively low temperature stage – at 1400…1450 ?C.
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The processes of thermal consolidation of nanoporous glass surface by means of carbon dioxide laser radiation have been investigated. Successful formation of a heat-sealed layer with a thickness of (20 ± 1) ?m was demonstrated under the following heat-sealing regime: average radiation power 10,5 W, defocusing ?f = 16 mm F-Theta lens with a focal length of 157 mm, scanning speed 40 mm/s, track spacing 100 ?m. It is shown that femtosecond pulses can be used to record birefringent structures through a thermally compacted layer, the magnitude of their phase shift being an indirect indicator of glass porosity.
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The paper shows micro-impurities and defects occurring in glass welded by two-stage method from natural quartz mined in the Urals. It is established that the quality of glass depends on the presence and distribution of mineral and gas-fluid inclusions in natural quartz, as well as on the fractional composition of the grains used and the conditions under which the welding process is carried out. It is noted that almost all trace elements in quartz, pass into the welded glass, thus, the trace element composition of the initial quartz is a critical factor determining its suitability for the production of high-quality transparent quartz glass.
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The results of investigation of properties (solubility, antiscaling, anticorrosive, algicidal, bactericidal) of glassy copper-zinc-containing phosphate composition (Cu–Zn–FC), which is obtained by waste-free ecological technology for the purpose of corrective treatment of make-up water in centralized heating systems, are presented. The synergetic effect of the joint presence of long-chain phosphates, alternating copper and zinc cations in the composition is revealed, which strengthens, evenly distributes the protective film on the surface of the system elements and provides maximum efficiency in the fight against salt deposits, corrosion, biofouling.
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The processes of obtaining selective vanadium-containing layers on the outer surface of tubular ceramic membranes based on a-Al2O3 for use in the petrochemical industry have been studied. A layer of V2O5?1.6H2O deposited on the outer surface of the ceramic membrane was obtained by the sol-gel method. The temperature of the heat treatment varied from 400 to 700 C. The chemical stability in a liquid medium of membranes with a deposited layer subjected to heat treatment at 650 C has been studied. It was found that the chemical stability of membranes with a V2O5 deposited layer is in the pH range from 5 to 8. The optimal heat treatment temperature for obtaining a layer with high adhesion to the substrate was 650 C.
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This work examines the main regularities in the formation of cement stone structure and the relationship between the properties of concrete mixes with various fillers and highly compressed materials obtained through the hyperpressing method. The objective of the study is to develop an efficient technology for producing construction materials using local, including non-standard raw materials and industrial waste, which is important both from an environmental and economic perspective. The experiment investigates the use of semi-dry pressing and hyperpressing to form concrete mixes with improved performance characteristics. It is assumed that during the pressing process, especially under hyperpressing conditions (pressures above 40 MPa), intensive interaction occurs between particles forming macroparticles, which contributes to a stronger cement stone structure. The involvement of Van der Waals forces and valence bonds between filler particles and hydrated clinker minerals, as well as molecular interactions, is considered the key mechanism for enhancing the strength and durability of the material. An important aspect is the use of low-plasticity clays, overburden rocks, and industrial waste, which significantly reduces production costs and improves environmental sustainability. The study also emphasizes that the hyperpressing technology helps reduce the technological cycle time, lowers specific energy consumption, and improves economic efficiency, making this technology promising for the production of environmentally friendly construction materials. The work contributes to the development of new methods for using secondary and local materials in construction, opening up new opportunities for improving the efficiency and sustainability of construction materials production.
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The glass-forming region in the ternary system TeO2–ZnO–MoO3 was investigated at two melt cooling rates. The achieved molybdenum trioxide content in the glass reached up to 80 mol. % with varying TeO? and ZnO ratios. The phase composition of the batch and the resulting glass under thermal treatment was studied using X-ray diffraction analysis. Within the temperature range of 20…300 °C, no significant interaction was observed between the initial binary oxides. However, upon further heating, complex oxide phases of tellurium (IV), zinc, and molybdenum (VI) (Te?MoO?, Zn?Te?O?, ZnMoO?, and ZnTeMoO?) were formed. The formation of these compounds was also observed during the induced crystallization of the glasses. Transmission spectra of the glass samples were recorded, revealing a redshift of the short-wavelength transmission edge with increasing molybdenum trioxide content.
