VOL 82, No. 2 (2009)

The influence of various technological parameters in the production of light porous granular glass-crystalline material based on zeolite-containing rocks has been studied. For the production of lightweight porous glass-crystalline material at temperatures corresponding to the technology for the production of foam glass (800 - 900 ° C), preliminary sintering of the charge must be carried out at a temperature of 700 ° C. It was found that an increase in the fineness of grinding the fritted charge to a particle size of less than 0.08 mm leads to a decrease in the bulk density of granular zeolite foam. Tab. 2, ill. 6, bibliography: 4 titles.

The possibilities of deposition of thin layers of silicon dioxide on the surface of quartz are investigated depending on the chemical composition of the initial reagents and the conditions of the process. The possibility of using silicon chloride and alcoholates for precipitation is shown. Tab. 2, bibliography: 3 titles.

The sequence of chemical transformations of elements of the surface layer of silicate glass of the system PbO - BaO - Na ₂ O - Al ₂ O ₃ - SiO ₂ when heated in a hydrogen atmosphere. The process of thermal reduction of multicomponent lead-silicate glass in hydrogen is a multistage process of diffusion and chemical interaction of lead with hydrogen. The reduction of lead is observed, and first the lead atoms associated with the alumino-oxygen groups interact with hydrogen, and then the lead atoms that are part of the silicon-oxygen structural units. The rest of the glass components in the temperature range 375 - 475 ° C do not interact with hydrogen. The concentration profiles of the distribution of elements in the surface layer of reduced glasses have been determined. Il. 3, bibliography: 8 titles.

The compositions of the masses have been synthesized and the conditions for their firing for the production of ceramic tips have been determined. The resulting structure of ceramics makes it possible to increase by 8 - 10 times the service life of the tips used in the device for monitoring the anti-corrosion protection of the Poisk-1 trunk pipelines. Tab. 1, ill. 2, bibliography: 4 titles.

The synthesis of cobaltite-gallates of the binary system LaCoO ₃ - LaGaO ₃ has been carried out. X-ray phase analysis showed that a continuous series of solid solutions of the composition LaCo _{1- x} Ga _x O ₃ is formed in the studied system. Found that solid solutions with 0 & # 8804; x & # 8804; 0.7 and 0.7 1- x Ga _x O ₃ solid solutions, caused by stretching vibrations, on the degree of substitution of Co < sup> 3+ in LaCoO ₃ with Ga ³⁺ ions made it possible to establish that the morphotropic boundary separating the regions of LaCo _{1- x Ga x O 3 with a rhombohedral and rhombohedral perovskite structure, passes near the composition of the solid solution with an x ??value slightly less than 0.7. Tab. 2, ill. 2, bibliography: 10 titles.}

Mineralogical and chemical analysis of kaolin-feldspar raw materials of the Chalganovskoye deposit was carried out. Experimental samples of electrical porcelain were obtained, their electrical and mechanical properties were investigated. Tab. 2, ill. 2, bibliography: 5 titles.

The process of dissolution of cristobalite during the firing of acid-resistant products based on Buskul clay with the use of granodiorite and felsite has been modeled. The mechanism of dissolution of cristobalite in their melts has been established. The dissolution of cristobalite in felsite and granodiorite melts can be divided into two stages. At the first stage, at low exposures, the dissolution rate is determined by the rate of silicate formation during the interaction of the melt formed when felsite or granodiorite is heated with cristobalite. In the second stage, with long exposures, the dissolution rate is determined by the diffusion rate, and the dissolution rate is significantly reduced. Tab. 4, ill. 1, bibliography: 7 titles.

The properties of hydroxyapatite (HAP) powder synthesized from calcium chloride and potassium hydrogen phosphate have been investigated. The powder material consists of HAP and a by-product containing predominantly KCl. After firing at temperatures above 800 ° C, the ceramics contains HAP as the main phase, as well as CaO and chlorapatite. The maximum density (2.2 g / cm ³) and the minimum grain size (200 - 500 nm) are observed in the material after firing at a temperature of 700 ° C. Il. 6, bibliography: 7 titles.

Prospects for obtaining heat-insulating foam glass with a protective and decorative coating are considered, which will increase the water resistance, durability of the material, and also improve its decorative properties. In addition, such a composite heat-insulating material can be used for architectural and artistic design of modern buildings and structures. Tab. 4, ill. 1, bibliography: 9 titles.

Changes in the structure, phase and chemical composition of two-layer heat-resistant ceramic coatings and surface layers of the ZhS6U alloy under the coating have been studied during high-temperature annealing and creep. Additional coating of ceramics containing 40% Y ₂ O ₃, 40% ZrO ₂, 10% Cr _{2 O 3, 10% Al 2 O 3 increases the creep resistance of the heat resistant alloy. Il. 2, bibliography: 5 titles.}