The processes of aggregation during the production of oxide powders and their compounds by chemical methods used for the manufacture of functional ceramics are considered. It is shown that the aggregation of powder particles prevents the production of high-density ceramics. Technological methods and conditions for the manufacture of products of high relative density have been established. Tab. 1, ill. 2, bibliography: 7 titles.
When clayey rocks are heated, the decomposition of organic matter is accompanied by the release of Н 2 , СО and СО 2 , which create a reducing nature of the gaseous environment. Burnout of residual carbon occurs in the temperature range 250 - 500 ° C and is extreme due to oxygen diffusion into the inner layers of the heat-treated material. To exclude the black core, it is recommended to provide exposure in the temperature range of 700 - 800 ° C to complete the oxygen burnout process, as well as to mold hollow products with the minimum permissible thickness of the outer and inner walls. Tab. 2, ill. 2, bibliography: 6 titles.
Multilayer aluminosilicate materials used for drinking water purification have been investigated. The main results of experimental studies obtained during the development of technological modes for the manufacture of aluminosilicate filter elements are presented. Tab. 2, ill. 3, bibliography: 4 titles.
The phase transformations occurring during the firing of clay from the Buskul deposit, granodiorite from the Seversky deposit and felsite from the Pokrovsky deposit, and mixtures of clay with granodiorite and felsite in different ratios have been investigated. By the method of quantitative X-ray phase analysis, the change in the content of crystalline phases (cristobalite, mullite and quartz) in the starting materials and mixtures during the firing process was established. Tab. 5, ill. 3, bibliography: 2 titles.
Various methods of manufacturing highly dispersed oxide powders and their compounds, which are used to obtain dense and durable ceramic materials with an adjustable microstructure, are considered. The most common chemical methods for producing highly dispersed powders, providing an even distribution of components. The use of the method of heterophase deposition makes it possible to obtain X-ray amorphous hydroxide powders, which are well filtered with a spherical aggregate size of 0.5 ?m or less. When calcined, the structure of hydroxides is transferred to the resulting oxides, from which high quality ceramic products are made. Tab. 1, ill. 1, bibliography: 14 titles.
The process of nitride formation during combustion in gaseous nitrogen of an iron-silicon alloy with additions of zircon concentrate has been investigated. It was found that the combustion of ferrosilicon in the presence of zircon (5 - 70%) is carried out in the surface mode, and the combustion products are multiphase. With optimal synthesis parameters (nitrogen pressure 4 - 7 MPa, sample diameter 35 - 40 mm), the combustion products are a composition consisting of a ceramic component (Si 3 N 4 - ZrO 2 -Si 2 N 2 O) and iron (& # 945; -Fe). A composite ceramic powder with a mass content of iron of 0.5% was obtained by the acid enrichment method. Tab. 1, ill. 3, bibliography: 5 titles.
The features of producing facing bricks by the method of plasma treatment with the combination of technological operations of reflow and spraying of decorative material based on technogenic raw materials are considered. A unified nomenclature of quality indicators for wall (front) ceramics has been developed. Tab. 2, bibliography: 3 titles.
A comprehensive study of the boron-containing component, colemanite, has been carried out. Glaze coatings have been synthesized with its application. The optimal content of colemanite in the composition of the charge composition is 3--6%, which makes it possible to expand the glaze formation interval by reducing the temperature of the appearance of the glassy phase from 1150 to 1000 ° C. While maintaining the required level of physical and chemical properties, the synthesized coatings are distinguished by high values ??of aesthetic indicators: gloss - 87%, whiteness - 89%. Il. 5, bibliography: 4 titles.
The results of research on the use of quartz-feldspar rocks of Ukraine (granites and pegmatites) as fluids in the production technology of stone-ceramic products are presented. A theoretical assessment of the fluxing ability of rocks is carried out, and a justification is given for the need to use additives in the mass compositions that reduce the viscosity of melts. The influence of the type and amount of fluids and additives on water absorption, fire shrinkage of specimens and their tendency to deformation has been investigated. The areas of optimal compositions of the masses, on the basis of which ceramic materials with the properties of porcelain stoneware are obtained, have been established. Tab. 3, ill. 2, bibliography: 7 titles.
Methods for manufacturing substrates based on low-temperature (sintering temperature below 1000 ° C), jointly fired with deposited metallization of ceramics are considered. Proposed materials promising for use as NSC in systems B 2 O 3 ? CaO? SiO 2 and B 2 O 3 ? CaO? Al 2 O 3 . Tab. 1, ill. 2, bibliography: 5 titles.
