Obtained porcelain stoneware based on Russian raw materials at a relatively low temperature in the range of 1200 & ndash; 1250 & # 176; C. X-ray phase, IR spectroscopic and electron microscopic analyzes showed the presence of quartz, cristobalite, mullite and glass phase in porcelain stoneware, and the content of the latter is not less than 50 & # 37 ;. High physical and mechanical properties: strength, frost resistance, heat resistance, etc. & ndash; porcelain stoneware gives mullite
The results of studies on the use of fluorides of sodium fluoride NaF and sodium tetraborate (borax), as well as their mixtures in the synthesis of foam glass materials based on diatomite raw materials according to & # 171; hydrated & # 187; are presented. mechanism using an alkali solution. The influence of NaF and borax on the process of formation of the structure of the material and the mechanism of their action during heat treatment have been investigated. The optimal ratios of the charge components and the temperature-time regimes for the synthesis of foam glass materials with the use of these additives as materials intensifying the sintering and melting processes have been established.
Ceramics in the Ca 2 P 2 O 7 -Ca (PO 3 ) 2 was obtained by firing a cement stone made from a powder mixture containing ?-tricalcium phosphate ?-Ca 3 (PO 4 ) 2 and monocalcium phosphate monohydrate Ca (H 2 PO 4 ) 2 & middot; Н 2 O. The Ca / P molar ratio of the starting powder mixtures was set to Ca / P & lt; 1. According to XRD data, all ceramic samples after firing at 1000 ° C included ?-calcium pyrophosphate ?-Ca 2 P 2 O 7 , and a ceramic sample from a powder mixture with a maximum content of monocalcium phosphate monohydrate Ca (H 2 PO 4 ) 2 & middot; H 2 O contained also ?-calcium polyphosphate ?-Ca (PO 3 ) 2 . The resulting calcium phosphate ceramics with a low firing temperature can be used to create a resorbable base for tissue engineering structures.
The microstructure and phase transformations of copper-doped BiNbO 4 ceramics synthesized at 950 and 1100 & # 176; C are investigated. According to XRD data, samples in a compact, pressed form crystallize in the ?-BiNbO 4 structure, regardless of the synthesis temperature and in spite of the phase transition ?. & # 8594; ? at 1040 & # 176; С. BiNb 1 & ndash; x O 4 & delta; xCuO (x & le; 0.04) preparations are graphite-colored composites with a visually pronounced grain microstructure. The thermograms of the samples show an endothermic effect near 900 ° C, associated with the decomposition of copper (II) oxide, and heat effects due to the occurrence of reconstructive phase transformations in BiNbO 4 of the ?; & # 8594; .gamma; & # 8594; ?. It was found that an impurity of copper oxide in the ceramics of bismuth orthoniobate acts as a heat sink, which leads to an increase in the phase transformation temperature .alpha. & # 8594; .gamma; when heating compact samples
The phosphate ore of the Polpinsky deposit contains up to 30 & # 37; silica. In the process of direct acidic processing of phosphorite into mineral fertilizers, silica is a ballast, which is advisable to be removed from the composition of the product. The possibility of using silica as a raw material for the glass industry was substantiated, for which its phase and chemical compositions were established and compared with the current technical conditions.
The chemical, phase composition and properties of metallurgical dust have been studied, and its structure and particle size distribution have been determined. The physical & ndash; chemical processes occurring during heat treatment of dust in the temperature range 20 & ndash; 1200 & # 176; C. On the basis of the studies carried out, the main directions of processing the studied dust in order to obtain useful products are proposed.
To ensure the uniformity of perlite rock in terms of density, a device of the simplest design has been developed, based on the Archimedes law, which allows determining the mass and volume of perlite rock right at the field and determining the average rock density from the obtained nomogram. The main physical and mechanical properties, closely correlated with the average density of the rock, are determined by calculation using the formulas obtained. The research carried out makes it possible to introduce the concept of grade and to stack the mined rock by density right on the quarry.
The issue of evaluating the efficiency of turning polymeric materials with cutting ceramics is considered. It has been experimentally proven that turning caprolon and fluoroplastic using a KNT16 cermet cutting insert provides a higher quality of the processed surface. This is evidenced by the lower values ??of the roughness parameters and the type of chips in comparison with the version of turning with tungsten-cobalt alloy VK8
The results of comprehensive studies of the physical and mechanical properties of ceramics from various regions of Kyrgyzstan, from the Bronze Age to the late Middle Ages, are considered. The complex consists of complementary methods: hardness measurement by the Rockwell method and density determination by hydrostatic weighing. The apparent density and water absorption were also determined and the open porosity was calculated. A comprehensive professional study of ceramics from different archaeological complexes will make a tangible contribution to the implementation of the development strategy of the republic, help to recreate a complete picture of the historical and cultural heritage of Kyrgyzstan
The effect of plasticizing additives on melamine formaldehyde (Melment F 15 G) and polycarboxylate base (Melflux 5581 F, Sika ViscoCrete-G2) on the properties of molding gypsum, consisting of ?-calcium sulfate hemihydrate, was investigated. Based on the results of the work carried out, the concentrations of additives were determined, allowing to increase the compressive strength of specimens from molding gypsum by 1.5 - mdash; 2 times
