VOL 82, No. 6 (2009)

The general provisions and features of the transfer phenomena in glass-forming melts and glass-making furnaces are considered. The interrelation of transport phenomena with physicochemical factors is shown, as well as the role of thermal diffusion phenomena in the formation of colored layers of molten glass. The importance of strict adherence to technological regimes for obtaining high-quality products was noted. Il. 3, bibliography: 8 titles.

The processes occurring during the production of glass fiber from glasses of various chemical compositions, as well as the influence of hydrostatic forces, surface tension forces and internal friction forces on the molding process are considered. The critical temperature of fiber spinning is determined under conditions when the forces of viscosity and surface tension of the glass melt are equal in magnitude. A new approach is proposed for assessing the fiberizing ability of glass in terms of surface tension to viscosity. A calculation method is given for evaluating the speed of forming glass fibers of various diameters by the example of glass E. Some mechanisms of adhesion of organic polymer and protein molecules to the glass surface are given. Tab. 2, bibliography: 7 titles.

The state of the art in the development of low-melting glasses, used, in particular, as fluxes for the production of silicate paints, is analyzed. The results of developments and patent data in this area for the last 30 years are presented. Tab. 3, bibliography: 12 titles.

Based on the calculations performed for various types of densest packings of spherical particles, it was concluded that it is possible to create in practice porous permeable ceramic materials with open porosity of more than 42 ±; 3%. The influence of the molding method (semi-dry pressing and slip casting), as well as the habit of crystals on the open porosity of ceramics, is shown. The assessment of the chemical resistance of the obtained porous ceramic materials in nitric acid and caustic soda is carried out. Tab. 4, ill. 4, bibliography: 7 titles.

The possibility of obtaining soft porcelain from ceramic masses based on unenriched kaolin from the Donetsk deposit is considered. The physical and mechanical properties and whiteness of the obtained samples were determined. The dependence of the reflection coefficient of individual porcelain phases on the Fe ₂ O ₃ content has been investigated. Tab. 4, ill. 1, bibliography: 4 titles.

The results of X-ray diffraction studies of two new modifications of aluminum oxide with tetragonal and hexagonal cells, synthesized by the explosion of a mixture of otktogen - aluminum hydride (90/10% by weight) are presented. Tetragonal cell parameters: a = 7.932 (6) & Aring ;, c = 9.142 (5) & Aring ;, c / a = 1.153, V = 575 & Aring; ³; hexagonal: a = 9.140 (3) & Aring ;, c = 3.980 (4) & Aring ;, c / a = 0.435, V = 288 & Aring; ³. Conversion matrices of cell parameters are given. Tab. 1, bibliography: 3 titles.

The peculiarities of staining the glaze in blue with adjustable shades have been studied. The physicochemical properties of glazes with a given content of cobalt oxide and modifier oxides carrying active oxygen have been determined. A glaze of optimal composition with high aesthetic and performance characteristics has been synthesized. Tab. 2, ill. 3, bibliography: 1 title.

The mineralizing effect of sodium fluoride, boric acid, and a natural fluorine-containing mineral (topaz concentrate) on the synthesis of ceramic pigments from talc with the structures of magnesium metasilicate, forsterite and diopside was investigated. It was found that the most active mineralizer is NaF. The positive effect of NaF not only on the synthesis of crystal structures, but also on the color of pigments was noted. The developed compositions of pigments can be widely used for coloring ceramic masses, in the production of building materials, for obtaining paints, coloring glazes and glasses. Tab. 2, ill. 3, bibliography: 3 titles.

A set of requirements for non-fired technological glass coatings to protect bronze during melting has been formulated, and their properties have been determined. With the help of DTA, the most critical temperature interval for the service of the developed coatings was established. Selected initial system Na ₂ O - B ₂ O ₃ - SiO ₂ and raw materials for the synthesis of glass coatings in it... By the method of mathematical planning of the experiment, the composition of the glass flux in the pseudo-triple silicate-lump - cullet - borax system is optimized. Tab. 1, ill. 3. bibliography: 9 titles.

An increase in the efficiency of grinding by reducing the consumption of diamond grinding wheels by choosing the optimal bond hardness and using more durable diamond powders with an optimal concentration is considered. New wheels on a bond of hardness HB100-105 with diamond powder AC50 - AC65 with a powder concentration of 62.5% are recommended for industrial use. Il. 3, bibliography: 4 titles.