VOL 77, No. 1 (2004)

It is shown that the transformations of iron oxides during glass melting proceed mainly in the solid phase. The ratio of the two forms of iron oxides in the molten glass is determined by the temperature of the melt. Achieving equilibrium between the melt and the gaseous medium requires a long time due to the high viscosity of the melt and low diffusion coefficients. To ensure high performance of products, the stability of the composition of raw materials and technological parameters of cooking, including the thermal transparency of the melt, are required. Il. 4, bibliography: 5 titles.

The processes of glass melting and the influence of the quality of the charge on them are considered. The study was carried out on the basis of a heat engineering survey of large-capacity glass-melting furnaces and mathematical modeling. The permissible impulse and multi-impulse deviations of the composition of the charge from the given recipe are estimated. Tab. 1, ill. 3, bibliography: 5 titles.

The glass formation, crystallization and physicochemical properties, as well as the structure of glasses of the PbO - ZnO - Bi ₂ O ₃ -B ₂ O ₃ - SiO ₂ in section with constant molar content of glass-formers (B ₂ O ₃ + SiO _{2) equal to 20%. A nonlinear dependence of the properties of glasses on their composition was revealed, due to a change in the coordination state of lead ions in the glass structure. The developed glasses are recommended to be used as a sealant and a sealant in the production of sensors of physical quantities of a new generation. Il. 3, bibliography: 10 titles.}

The fundamentals of obtaining optically transparent glass-crystalline materials from industrial wastes are considered. The intensity of their transmission spectra in the visible region of the spectrum, the temperature dependence of the logarithm of the resistivity, thermal conductivity, and TCR are studied. It is shown that the addition of 30% lithium oxide to the composition of a glass-crystalline material leads to a decrease in its TCR. Il. 5, bibliography: 11 titles.

To obtain highly dispersed, sintering-active forsterite powders, the sol-gel method was used. On the basis of these powders, a sufficiently strong and dense ceramic was obtained without additives at a firing temperature of 1350 ° C; however, complete sintering of forsterite is difficult due to intense recrystallization. Tab. 1, ill. 1, bibliography: 7 titles.

The results of experiments on hardening miniature bushings with an outer diameter of 1.2 - 3.5 mm made of forsterite ceramics by impregnation in salt solutions are presented. It is shown that an increase in the temperature of the first firing and a decrease in the duration of impregnation of semi-finished products leads to an increase in strength from 47% to 2.7 times, depending on the size of the products. The mathematical processing of the experimental results was carried out by the spline interpolation method. Tab. 2, ill. 2, bibliography: 3 titles.

The effect of a new viscosity reducer - 40% PAN (sodium polyacrylate) - on the rheological properties of majolica slip, as well as water hardness on the change in the moisture content of the suspension has been studied. The use of 40% PAN makes it possible to reduce its content in the slip by almost 2 times in comparison with water glass, improve the rheological properties of the slip, and also slightly reduce its moisture content. The optimal content of 40% PAN has been established for thinning slip from polymineral clay from the Gzhel deposit and majolica mass. Tab. 2, ill. 2, bibliography: 1 title.

A muffled colored glaze for facing tiles based on float waste from a copper processing plant was obtained. The optimal compositions of glazes with good physicochemical properties have been determined. Tab. 2, bibliography: 5 titles.

The possibility of using natural and technogenic raw materials of KMA - quartzite sandstones - for the introduction of silicon oxide in the production of medical containers, as well as dust from electrostatic precipitators of the Oskol Electrometallurgical Plant as an unconventional dye for obtaining brown pharmaceutical containers has been investigated. The properties of experimental glasses based on quartzite sandstones were not inferior to industrial ones and corresponded to the requirements for medical containers. The prospects of staining the molten glass with the dust of electrostatic precipitators in the feeder channel are shown. Tab. 2, bibliography: 6 titles.

The use of new, unconventional ways to improve the quality of clay raw materials (mechanical activation, modification, ultrasonic treatment, electrochemical activation, introduction of unconventional additives, pulsation enrichment, etc.) and selection of process parameters (charge composition, particle size distribution of press powder, firing mode, etc.) ) made it possible to obtain building ceramics (brick, tile, tile) with improved performance from low-quality clay raw materials of the Republic of Tatarstan.