VOL 83, No. 2 (2010)

The results of research in the field of synthesis of barium-zirconium lead-free sorted glasses, the optical performance of which are not inferior to those of lead-containing ones, are presented. Glasses are well boiled and clarified at a cooking temperature of 1450 ° C. Recommended glass compositions have a refractive index of 1.552 - 1.556, average dispersion (957... 961) ?; 10 ^-5 and contain 12 - 13% (BaO + ZrO ₂). 2, ill. 4, bibliography: 2 titles.

It was found that the content of the modifier - chemically modified bottoms of caprolactam distillation (MCODK) - plays a significant role in the liquefaction of ceramic masses. At a content of 0.5 - 1.0% MKODK, liquefaction occurs, and over 1.0% - hydrophobization of the clay surface as a result of its interaction with organic matter. Tab. 2, ill. 2, bibliography: 4 titles.

The technology of manufacturing two- and three-fraction ceramic composite materials by slip casting is considered. Their structural parameters have been investigated. The strength of the materials has been determined. An abnormal increase in the strength of the material in the region of the percolation threshold (filler content - 16%) was found, which is a consequence of the structural effect. Tab. 3, ill. 4, bibliography: 6 titles.

The process of formation of composite ceramics based on the SiO ₂ - Al ₂ O ₃ - TiO ₂ system with the addition of nanostructured powders has been investigated ? - and ?-Al ₂ O ₃ during heat treatment in the temperature range 1300 - 1400 ° C. It was found that the introduction of a reactive nanostructured powder ?-Al ₂ O ₃ stimulated the solid-phase reaction between silica and alumina with the formation of mullite, and the addition of ?-Al < sub> 2 O ₃ promoted the formation of aluminum titanate. These processes changed the phase composition, porous and crystalline structure of the composites and increased their physicomechanical and thermophysical characteristics. Il. 4, bibliography: 8 titles.

It is shown that the electrical conductivity of TiO ₂ (rutile) can be increased by doping it with oxides of higher valence elements. The introduction of semiconductor TiO ₂ into the glass enamel slip can significantly reduce the electrical resistance of the composite coating. Il. 2, bibliography: 4 titles.

As a result of vacuum-thermal treatment of ilmenite-leucoxene concentrate modified with magnesium oxide additives, a porous silicatoferropseudobrukite composite material was synthesized, exhibiting the properties of an n-type ceramic semiconductor. The microstructure, chemical and phase compositions are described, the mechanical and electrophysical characteristics of the obtained material are investigated. Tab. 1, ill. 4, bibliography: 15 titles.

A technology has been developed for producing decorative building ceramics - red tiles with various shades based on red-burning clay. Used complex additives, consisting of production waste (alumo-cobalt-molybdenum catalysts) and wollastonite, containing color-bearing strengthening and improving sintering oxides. This makes it possible not only to activate the sintering process, but also to obtain building ceramics of a wide range of colors, as well as to solve the problem of recycling production waste and expanding the raw material base for the manufacture of ceramic products. Tab. 3, bibliography: 3 titles.

Heat losses are considered by the example of a tunnel kiln for firing porcelain and refractory materials. Calculations of heat losses through the roof of the furnace when using diatomite chips and granular glass-ceramic foam as heat-insulating backfill have been carried out. Economic calculations have shown the advantage of using granular glass ceramic foam. Tab. 4, ill. 2, bibliography: 6 titles.

The productivity of a belt vacuum press during the formation of ceramic masses has been studied depending on the specific pressing pressure, productivity losses during press wear and geometric factors affecting productivity. The results of determining the geometric parameters affecting the productivity of the press are presented. Tab. 1, ill. 4, bibliography: 3 titles.