VOL 94, No. 7 (2021)

The influence of a number of modifying additives: calcium fluoride, zinc oxide and boron oxide, on the melting and crystallization properties of strontium aluminosilicate glasses is considered. The influence of the type and amount of the modifying additive on the homogeneity of the molten glass and the quality of glass castings was visually evaluated. The influence of additives on the formation of the crystal structure of glasses was studied by methods of mass crystallization and XRD.

The advantages of alkoxy technology as one of the types of the sol-gel method for the synthesis of ceramics and glass ceramics are shown; an overview of the methods for the synthesis of alkoxides and oxides based on them is presented. The results of experimental studies on the production of mullite glass-ceramics using the alkox technology method are described, the structural and phase transformations of the intermediate product in the process of mullite synthesis are studied.

A technology has been developed for producing glass microspheres in a plasma reactor based on the wastes of enrichment of ferruginous quartzites KMA. The regularities of the influence of the flow rate of the plasma-forming argon gas and the power of the plasma reactor on the fractional composition have been established. It is shown that with an increase in the flow rate of the plasma-forming gas from 1.5 to 2.5 m3 / h and the current strength from 400 to 500 A due to the processes of coagulation, the amount of the fraction over 630 ?m increases. It has been shown that glass microspheres are enriched in aluminum and calcium oxides and depleted in silicon, magnesium, sodium, potassium, and iron oxides. It was found that under the action of high plasma temperatures, of the order of 9000 & # 150; 12,000 K, there is a complete melting and spherization of the particles with the formation of glass microspheres with a size of 80 to 1250 microns. The following operational parameters of glass microspheres based on the wastes of enrichment of ferruginous quartzites of KMA, such as microhardness, acid resistance and alkali resistance, have been investigated.

It is shown for the first time that the slurry evacuation method can be used within the technology of manufacturing large-size radio-technical items from quartz ceramics. According to the results of the study, it was found that evacuation of a slip based on quartz glass before molding ceramic blanks makes it possible to increase the level of density values ??of the ceramic material by 0.01 g / cm ³ and improve its uniformity by more than 30 & # 37; , as well as to reduce the number of cavities in products made of quartz ceramics by removing air from the slip

The effect of the content of silicon carbide whiskers and the sintering temperature on the physicomechanical and thermophysical properties of samples of a ceramic composite material (CMC) of the SiC & # 150; SiC _w & # 150; B ₄ system has been investigated. C & # 150; AlN with a mass content of silicon carbide whiskers (SiC _w) 10, 30 and 50 & # 37; obtained by the method of spark plasma sintering. The introduction of silicon carbide whiskers SiC _w into the CMC of the SiC & # 150; B ₄ C & # 150; AlN system led to an increase in bending strength and crack resistance, and at a mass content of SiC _w 30 and 50 & # 37; values ??of strength and crack resistance of PFC are at the same level

The results of studies of the structure and properties of traditional ceramic stone masses, including in the initial composition emaciated, flux and clay materials (respectively 36, 14 and 50 & # 37; by weight) with a systematic change in the ratio of kaolinite and illite-containing clays and temperature-time conditions of firing in the temperature range 1000 & # 150; 1300 & # 176; C. As a result of studies of the structure, phase composition, dilatometric and ceramic properties, the optimal ratios of kaolinite and illite clays and the sintering conditions under which the ceramic properties of the material are realized are determined. It is shown that the maximum compaction of ceramics (open porosity / water absorption 2 & # 150; 5 & # 37;, apparent density & # 8805; 2 g / cm ³) is achieved in the range of sintered state 1150 & # 150 ; 1250 & # 176; C and is realized while maintaining the equivalent mass ratios of both clays in the original compositions close to 1: 1

The criteria for achieving a synergistic effect for the improvement and control of the process of obtaining heat-insulating porous materials using igneous rocks of the crystalline basement of the south of the Republic of Belarus have been studied and experimentally confirmed. These include physicochemical processes in ceramic masses (raw granules) during heating and optimal conditions for heat treatment. The data of differential scanning calorimetry in combination with the study of the specificity of the formation of the porous structure and physicochemical properties made it possible to develop scientific foundations for managing the process of obtaining heat-insulating materials.