Abstract: The properties of overburden rocks in the extraction of dolomite in the form of red-burning clay from the Kurgan region are investigated to determine its suitability in the production of various types of ceramic materials and products. A full technological study of the clay raw material sample was carried out: the mineral, chemical, particle size composition, as well as plasticity, drying behavior, attitude to sintering, and mechanical strength after burning. It is examined how rheological characteristics affect the control of the technological process. The suitability of clay under consideration, both in majolica ceramics and ceramic bricks production, has been established. The technological parameters for the ceramic bricks production are developed.
Abstract: Comparative assessment of phase formation in the system ZnO-CeO2-Fe2O3-Cr2O3, obtained using a number of technological methods, is carried out. Spinel phase formation is established for all materials studied, except ZnO-CeO2. Synthesized materials are examined with X-ray phase analysis, low-temperature nitrogen adsorption, and scanning electron microscopy. It is shown that the synthesis in the presence of an organic precursor allows obtaining fine spinel samples. High catalytic activity of the synthesized materials, containing the spinel phase, is established in the process of methyl orange oxidative destruction in the presence of hydrogen peroxide. It is proved that with an increase in the number of chromium cations in the sample, the catalytic activity of the materials also increases. Zinc ferrite, despite the considerably more developed surface, and ZnO /CeO2 are not very effective in this process. The data obtained is useful for the development of materials for wastewater treatment at industrial enterprises, which use organic dyes in their production cycles.
Abstract: The process of silicon carbide producing (SiC) in a resistance furnace is accompanied by moisture movement in the batch. An important consideration is the accounting of moisture transfer in the preparation of the mathematical description of the process. The aim of the article is to improve the existing model of heat and mass transfer in SiC production.
Abstract: The process of pressing a graphite-plastic composition is modeled by using plasticity theory methods. We have thus obtained dependencies for computing the pressure necessary to fill the space between the hard particles with the soft component of this composition. The paper presents an estimation of the energy intensity of this process.
Abstract: The article considers the method of stabilizing roadbed soils by introducing metallurgical waste in the structure of the composite binder. It was established during the analysis and experimental research that construction engineering properties are improved as a result of the method. The article provides the obtained results of laboratory tests. The optimum amount of ground blast furnace slag as a component to replace part of Portland cement in a soil cement mix is determined. The dependence of strength gain on the hardening time at different proportions of the composite binder is given. The efficiency of the considered method of soil hardening is estimated.
Abstract: Studies of the influence of vibration impact on the strength of foam-ceramic raw material, produced on the basis of chemically modified natural silicites, are presented. The natural oscillation frequencies of mineral particles are established, taking into account their size, density and ultimate shear stress of raw suspensions. It is shown that the coincidence of the natural and forced oscillations of the particles leads to an increase in the thixotropic effect. Using the technology of a controlled ?sol-gel? transition in the structure of raw material, swelling under the influence of vibration load, samples of the material were obtained with a higher-quality macrostructure without the use of binders. Indicators of compressive strength and average density of raw and ceramics are given.
Abstract: A model of the transition layer between the shell and the core of a ceramic matrix composite from coal waste and clay has been developed. The chemical, granulometric and mineral compositions of the beneficiation of carbonaceous mudstones and clay were studied. The technological and ceramic properties of raw materials for the samples manufacturing were determined. The method of manufacturing multilayer ceramic samples from coal waste, clay and their mixture is given. The number of transition layers in the contact zone between the clay shell and the core from coal wastes is determined. The deformation and swelling phenomena of model samples from coal wastes, clay, and their mixtures were revealed at the firing temperature of more than 1000 °C. The formation of a reducing ambient in the center of the sample with insufficient air flow is shown. The influence of the carbonaceous particles amount and the ferrous form iron oxide in the coal wastes on the processes of expansion of multilayer samples during firing has been established.
Abstract: The scientific article presents a physical model of the technical process of co-extrusion processing of secondary polymeric materials. A set of tools for automated control and monitoring of the model is considered, which allows to adjust smoothly the values of the rotational speeds of screws of extruders, the temperatures in the material heating zones and the pressure at the outlet of the co-extrusion head. The results of experiments to determine the temperature of the parison over a cooling time and the effect of screw speed and pressure in the head on the quality of mixing components are given. The results obtained by physical modeling confirm the correctness of the authors' calculations performed using the proposed mathematical models. Thus, it is possible to continue research in this direction, the result of which will be new designs of co-extrusion equipment, allowing to process efficiently polymeric waste into new high-quality products.
Abstract: The results of a research of a way of receiving a composite sorbent with the use of waste of production and processing of the micaceous quartzites (MQ) and montmorillonite clays (MC) are given in this work. The structure of composite sorbents was caused by aspiration as much as possible, to use positive properties of all components entering composition: their high sorption, knitting and plasticizing properties. Similar approach to a combination of components gives, as a result, a synergetic effect, allows to receive the highly effective and, at the same time, inexpensive, rather universal materials having high sorption properties. The sorption activity is investigated, the efficiency of natural and composite sorbents is defined, the increase in sorption activity, depending on structure of composition and temperature of preliminary preparation of a sorbent, is proved. Application of the offered composite sorbents will allow to solve in a complex the existing ecological problems: to carry out effective purification of industrial sewage, first of all, machine-building enterprises from ions of heavy metals, and to utilize waste of production and processing of micaceous quartz.