Key Engineering Materials Vol. 743

Abstract: In this paper the features of separation processes modelling are analyzed in hydrocarbonic media within the limits of thermodynamics of equilibrium states. Approaches to calculation of phase equilibrium in multicomponent systems are discussed. Regularities and peculiarities of composition change of gas mixture depending on the temperature and pressure are studied. It has been established that there are specific conditions of non-monotonic change of composition with extremums for some separation regimes that significantly influences the physical properties and intensity of exchange processes at the heat-and mass transfer in multicomponent hydrocarbon media. In addition, the details of the behavior of gas phase with changing its thermal and physical properties have been discussed. Also, the calculated distributions of Prandtl, Schmidt and Lewis-Semenov numbers essentially influencing on the intensity of transport processes are considered.

Abstract: The developed mathematical description of heat treatment of the crushed wood in rotary drum dryers, and also the results of the mathematical description of the studied process is presented in the article. The results of mathematical modeling have shown that with increase in the diameter of a drum by 3 times its length can be reduced almost by 7 times due to the increase in the relative stay time of particles in flight. It provides the best interaction of particles with the heat carrier. Increase in speed of rotation of the drum twice also allows reducing its length almost by 3 times, but at the same time energy consumption increases and crushing of raw wood materials is observed. It was established that the practical speed of the heat carrier is 0.75-2.6 m/s, which limits the drum length to no more than 8-10 meters.

Abstract: Flow distribution is an important process step of many technologies such as heating or cooling systems, microchannel reactors, bubble columns and fixed- or fluidized-bed reactors etc. The present work is devoted to numerical simulation of flow distribution in the pre-reactor unit of the packed bed reactor used for filtrating combustion of fuel mixtures. A special modification of the construction is considered namely the construction with a nozzle for fuel mixture supply placed on the sidewall of the apparatus. The problem formulation, the best practices and opportunities of numerical simulation of the flow distribution effect in packed bed reactors are discussed in the present paper. The length of the flow distribution zone in a wide range of mixture inlet velocity is calculated.

Abstract: The results of hand calculation of boric acid accumulation in the core in a new generation WWER-TOI reactor in case of LOCA are presented. Variants of reducing the H₃BO₃ concentration in the HA-3 system down to 1, 2, 4 and 8 g/kg are considered. The mass of boric acid deposits on the core internals depending on the value of boric acid concentration in the HA-3 system is determined. The obtained results allow concluding that the accumulation and crystallization of boric acid in the core is possible.

Abstract: In the recent years, due to the introduction of new Technical Regulations in the Oil and Gas Industry in 2008, high technical and environmental performance values were set to be met by production volume and by the quality of hydrocarbons and a variety of oil products coming from the fields to factory processing and trade parks. The presence of a powerful raw material base, the shortage of petroleum products and the development of market relations create objective conditions for increased use of a variety of natural hydrocarbons, for improved technological schemes of oil preparation and oil processing on the oil fields and for modernizing the equipment used. On small and remote oil fields, which for economic reasons cannot be linked by transport pipelines, a complex system of preparation of liquid hydrocarbons is used with the ultimate goal of obtaining some refined products such as gasoline, diesel fuel and furnace oil.

Abstract: Though silicate-oxide materials are in demand in all industries, inclusive of defense industry, their application is limited by manufacturing capability of their formation. Therefore, range expansion of manufacturing capability of forming silicate-oxide materials is an important issue. Casting technology allows obtaining fair-sized items and composite pattern at lower cost. It is used for silicate-oxide materials in petrurgical (stone casting) manufacturing, the melt for stone casting technology being often received by electric arc method.

Abstract: Slag bases for welding materials have been developed from mineral raw materials and man–made mineral formations of the Urals. Successful comprehensive studies and tests of fused fluxes and also of weld metal and weld joints obtained by these welding materials have been carried out. It has been clearly established that the obtained weld metal has low content of harmful impurities ([S] is as low as 0.01 wt%) due to the use of the electric arc furnace method, purity of the feedstock minerals and technogenic raw materials and physicochemical reactions during the welding process.

Abstract: The development of mineral resources requires predicting its possible impact on the undermined rock mass. The aim of this work is to ensure safe and efficient extraction and minimization of losses. This article considers the problem of formation of water conducting fracture zones in terms of its predictability using the finite elements method.

Abstract: The Podgolechnoe deposit, which belongs to the alkalic-type (A-type) epithermal gold-ore deposits, lies in the Central Aldan ore district (Russia). Gold-ore mineralization is associated with a volcano-plutonic complex made of rocks of the monzonite-syenite formation (J₃–K₁). The ore bodies are localized in the crushing zones developed after crystalline schists, gneisses, and granites of the crystalline basement complexes (Ar–Pr). Metasomatic alterations in host rocks have potassic specialization. Vein ore minerals are adular, fluorite, roscoelite, sericite, and carbonate. Ore minerals are pyrite, galena, sphalerite, cinnabar, brannerite, monazite, bismuth telluride, stutzite, hessite, petzite, montbraite, and native gold. The deposit has been explored as a gold-ore deposit, however, due to complex composition of ores there is a need to reveal the possibilities of the integrated development of this deposit. This could provide for a reserve increment and an increase in the gross recoverable value of ores due to the extraction of associated components.

Abstract: The Central Aldan ore district is a geologically unique area, representing the conjunction zone of the ancient structures of the Archean–Proterozoic crystalline shield, overlain by the Vendian–Cambrian sedimentary cover. The latter was formed in the Mesozoic by intensive alkaline magmatism. Within the Central Aldan ore district, most of primary gold-ore deposits are confined to the sedimentary cover. Until recently it was considered that only ancient complexes in the crystalline basement contain commercial Au-U mineralization. As a result of the geological exploration works over the period of 2003–2006, the Podgolechnoe deposit was discovered. Gold mineralization in this deposit occurs both in rocks of sedimentary cover and crystalline basement. Ore bodies in rocks of the crystalline basement (A-type alkaline deposits) contain epithermal gold-telluride (Au-Te) mineralization, which is new for Central Aldan ore district. This work presents results of the study of geochemical composition of the Podgolechnoe deposit ores and their comparison with typical epithermal gold-ore deposits. In total, 15 samples were studied. The homogeneity of the sample collection, the correlation between Au and other elements, the enrichment coefficients of elements-admixtures, and the REE distribution were analyzed. It was established that gold ores of the Podgolechnoe deposit are geochemically heterogeneous, but, in general, they correspond to the geochemical spectrum characteristic of the gold ores of A-type epithermal deposits. In contrast to Au-U deposits, common in the studied area, ores of the Podgolechnoe deposit show no correlation between gold and uranium.