VOL 84, No. 10 (2011)

Partial sections of the BaO system - La ₂ O ₃ - B ₂ O ₃ - TiO _{2 < / sub> - SiO 2, regions of a stable glassy state are determined. The regularities of the influence of titanium, lanthanum and barium oxides on the crystallization ability of experimental glasses, optical and thermal characteristics have been established. Optical glass was obtained with a refractive index of 1.81, an average dispersion of 0.0187, an LTEC value of 76.8 x middot; 10 ^-7 К ^-1, which can be recommended for obtaining high-refractive optical lenses, as well as glass for the light-guiding core of an optical fiber. Tab. 2, ill. 5, bibliography: 3 titles.}

The separation of the components of the glass batch during its storage and transportation is considered. A study of segregation in a two-component soda - sand system was carried out. It is shown that soda, as a lighter material, almost completely passes into the upper layers of the charge. By studying the segregation of various fractions of powdered dolomite, it has been established that mechanical action on powdered dolomite leads to a redistribution of fractions: the coarse fraction is dislocated in the upper layers of the charge, and the small fraction remains below. Il. 4, bibliography: 1 title.

An approximation formula is proposed for calculating the viscosity of molten basalt glasses from the chemical composition of the initial mineral raw materials, obtained as a result of multivariate regression analysis of a set, including 27 rocks. In the simulation, the experimental values ??of the viscosity of the melts and the data on the content of oxides in the feed, determined by the X-ray fluorescence method, were used. The formula allows predicting the viscosity of melts at a given temperature with a high degree of accuracy. Tab. 1, ill. 1, bibliography: 8 titles.

The influence of the concentration of H ₂ SO ₄, HCl, NaOH and Na ₂ CO ₃ on the chemical resistance of porous permeable ceramics based on electrocorundum and aluminosilicate bond. It is shown that the chemical resistance of porous ceramics of the chemical composition selected for testing depends on the type and concentration of the reagent solution taken for testing. Porous ceramics are the least chemically stable in concentrated sodium hydroxide solutions. The most chemically stable porous ceramics in solutions of soda ash of any concentration. Porous ceramics have minimal acid resistance in a sulfuric acid solution at a concentration of 90 - 80%. Tab. 5, ill. 3, bibliography: 5 titles.

Data on the rheological behavior of samples of materials of the porcelain group at pure shear were obtained, complementing the results of dilatometric studies of shrinkage. The concept of the macromechanism of deformation along the critical regions is proposed, which explains the shear deformation in the low-temperature region, which is carried out due to the sliding of grains along the boundaries of their contacts (СЗ). The presence of a constant (with respect to the heating temperature and significant up to 1200 ° C) structural-rheological component was found, which is responsible for the dilatant behavior caused by the SZ. In the temperature regions of intense crystallization of mullite, the maximum rate of shrinkage corresponds to the maximum rate of increase in viscosity. Il. 12, bibliography: 14 titles.

Fine-dispersed powders of REE ferrites were obtained by the "wet combustion" method. The solid-phase synthesis of lanthanum-gadolinium ferrite has been studied. It has been shown that the target phase can be obtained at temperatures up to 750 ° C. Firing modes have been found that make it possible to obtain ceramics based on REE ferrites with low open porosity and relative density up to 99% of theoretical. Tab. 2, ill. 3., bibliography: 4 titles.

Developed "universal" frit-free coatings for heat treatment of high-strength steels of the VKS type. The kinetics of oxidation of VKS steel with and without coating has been investigated. The efficiency of application of a frit-free coating on semi-finished products made of steels of the VKS type is shown. Il. 1, bibliography: 2 titles.

Calculation formulas are given for determining the stiffness of the elastic suspension of a vertical vibrating sieve taking into account the factors affecting the performance of the sieve when filtering ceramic suspensions. The frequencies and amplitude of vibrations are recommended, at which the optimal operation of the sieve is ensured while maintaining the durability and performance of its structure. Il. 1, bibliography: 3 titles.