VOL 79, No. 12 (2006)

The structure of glasses of compositions xEr ₂ O ₃ - 2xTiO ₂ - (100-3x) TeO ₂ was studied and the region glass formation, which is in the range 2

The sequence of adaptation of a conjugate mathematical model describing external heat transfer in the working space, as well as heat transfer and hydrodynamics of the melt in the melting basin of a glass-making furnace with a horseshoe-shaped flame is considered. It is shown that with the correct setting of the basic boundary conditions for modeling to adapt the model, it is sufficient to use the experimental dependences of the air heating temperature and the temperature of the molten glass at the outlet from the melting basin on the furnace productivity. Equations have been obtained that establish the relationship between the specific heat consumption and the maximum melting temperature and the specific removal of molten glass, which can be used in constructing an algorithm for controlling the thermal operation of a glass-melting furnace of the investigated design. Il. 3, bibliography: 7 titles.

The character of oxygen and nitrogen diffusion in the surface layer of nitrided lead-silicate glass has been studied. The dependences of the diffusion coefficients on the composition of the glass and the duration of the gas thermal treatment have been established. Il. 2, bibliography: 12 titles.

A porous heat-resistant composite material has been developed from natural powders, which form a cordierite matrix during sintering, and a filler - a fibrous nanostructured aluminum oxide powder with high porosity and reactivity. It was found that the introduction of a nanocrystalline filler of aluminum oxide into a composite with a cordierite matrix causes the formation of a polyporous structure that increases porosity and heat resistance, as well as improves the thermal insulation properties of the material. Il. 5, bibliography: 8 titles.

The effect of the nature of magnesium salts on the synthesis and sintering of cordierite powders obtained by the sol-gel method has been established. The phase composition of the powder and the behavior of the material during sintering depend on the calcination temperature of the xerogels. Tab. 2, ill. 3, bibliography: 8 titles.

The results of studies of the process of obtaining mullite from quartz-topaz and molding finished mullite products directly at the stage of mullitization of topaz concentrate are presented. The use of the proposed technology makes it possible to manufacture lightweight refractory products with a fibrous microstructure and to minimize the number of intermediate operations. Il. 5, bibliography: 8 titles.

The velocity of propagation of ultrasonic waves and absorption of ultrasound in beryllium ceramic samples of various densities, configurations, and sizes, differing in the molding method and degree of texturing of BeO microcrystals, have been investigated at room and low temperatures (about 100 K). It was found that with an increase in the density of the samples, the speed of propagation of ultrasound in them increases. It is shown that the speed of ultrasound in beryllium ceramics without specially introduced impurities weakly depends on the frequency in the range of 5 - 25 MHz. Tab. 5, ill. 1, bibliography: 13 titles.

Ceramic pigments have been synthesized, which are microgranules of waste generated in the process of grinding optical glasses, the surface of which is covered with two layers - silica and crystals & # 945; -Fe ₂ O ₃, & # 945; -Al ₂ O ₃ and FeAl ₂ O ₄. The resulting pigments can be used to make enamels for glass, metal and porcelain. Il. 3, bibliography: 5 titles.