Introduction. Agricultural land use organized in the dry steppe Kulunda of Altai Krai, with an area of more than 1,8 million hectares, is unsustainable. This is due to many factors, but the main ones are agro-climatic conditions (temperature and precipitation), as well as anthropogenic elements of landscapes, as a result of the joint manifestation of which erosion processes develop. The purpose of the study: to conduct a multicomponent analysis of agricultural lands in the dry steppe Kulunda Altai Krai to optimize their agro- and geo-ecological state, as well as increase the sustainability of agricultural landscapes. Research methods: a systematic approach and a comparative geographical method used in the processing of materials characterizing the qualitative and quantitative indicators of agricultural landscapes and the analysis of zonal physical and geographical characteristics of the territory. Relationships and mutual influences within anthropogenic landscapes have been studied using the ecological-landscape approach. Research results. Over a thirty-year period of monitoring the heat and moisture supply of the territory, it was found that only 1-2 years per decade are optimal for growing crops (spring wheat), and agricultural land prevails in the structure of the land fund (seven municipal districts), and their share varies from 47 % to 96 % in Uglovsky and Tabunsky districts, respectively. Examining the structure of sown areas and crop rotations, it was found that arable land is the most common agricultural land, it accounts for more than 70 %, pastures – almost 20 %, hayfields and fallow lands – 8,5 %, perennial plantations – only 0,04%. It was determined that cultivated crop rotations lead to degradation of the soil cover, which occurs due to active dehumification – the loss of humus reserves in the process of deflation and active mineralization on fallows and fields with tilled crops. It was calculated that the rate of humus loss on an area of one hectare is 0,24 tons per year. Conclusion. The calculations made show that the coefficient of environmental stability is much lower than the threshold, and a relatively high indicator of environmental stability in the Mikhailovsky and Uglovsky districts was achieved due to the tape forest and salt lakes located on their territory, which do not have a positive impact on the sustainability of agricultural areas. Improving the sustainability of agricultural land use is possible with the organization of a grass field system by changing the structure of sown areas and crop rotations.
Introduction. Currently, many metallurgical companies in Russia are experiencing difficulties with the supply of raw materials. One of the solutions to this problem is the involvement in the reuse of secondary resources that are formed in metallurgical processing. So there are more than 15 million tons of them on the territory of Zlatoust steel Mill. The development of metallurgical slag processing technology will partially solve the problem of the company’s own raw material base. Methodology. To develop an effective technology for complex processing of metallurgical slags of Zlatoust steel Mill four samples were taken from various sections of slag dumps. Research results and discussion. The work studied the chemical and mineralogical composition of samples, conducted studies on the enrichment of slags. To study the enrichment of metallurgical slags by the magnetic enrichment method, studies have been carried out, including separation of material with a size of -100 +40 mm on a drum separator and material with a size of -40+0 mm on a separator in a suspended state. The results show that products made of a material with a size of -100+40 mm meet the requirements for direct use in blast furnace production. and products obtained from a size class of -40+0 mm meet the requirements of agglomeration production. The chemical analysis of the obtained products after magnetic separation in a suspended state indicates significant nickel content in the magnetic separation tails of the sample with a size of -40+0 mm. The study of the microstructure of the sample showed that the size of nickel inclusions is on average 1 mm. In this work studies have been carried out on the grinding of tails to a size of less than 1 mm and enrichment on gravity apparatuses. Studies comparing the results of metallurgical slag enrichment on a concentration table and a centrifugal concentrator have shown significantly higher efficiency of slag separation on a centrifugal concentrator. Conclusions. The obtained results on the enrichment of metallurgical slags ofZlatoust steel Mill allows us to recommend a comprehensive processing technology. As a result of enrichment the following products are obtained: magnetic product 1 with a mass fraction of iron 88.4% when extracting 35.2%. magnetic product 2 with a mass fraction of iron 42.7% when extracting 12.4% and nickel-containing concentrate with a mass fraction of nickel 4.85% when extracting 67.9%.
The article deals with the state of aerogasdynamic processes in coal mines. With centralized automatic control and management of mine ventilation using a control system, in the circuit of which application software is used, the choice of a rational period for collecting information received from controlled objects is of great importance.The object of automatic control in a coal mine are the parameters characterizing the state of the mine atmosphere - methane concentration, air flow, temperature and parameters of the ventilation network (depression and aerodynamic resistance). All controlled parameters characterize the state of the atmosphere. Research goal. The purpose of the research is to develop a method for analyzing and evaluating the optimal state of aerogasdynamic processes in coal mines. Research objectives. Conduct an analysis of the optimal state of aero- gasdynamic processes and adapt the method at coal industry enterprises. Research results. Studies have been carried out on the duration of the observation interval for the modes of movement of air and gas through the goaf and bottom-hole space of the production area, to ensure the specified accuracy in determining the values for the implementation of non-stationary gas-dynamic processes. It is determined that the resulting systems of equations describing the unsteady modes of air and gas movement through the mined-out and bottom-hole space of the mining area from the standpoint of hydrodynamics with subsequent simplification of these equations based on the assumptions made. Using the results of the experiments, for the process of methane concentration, a realization length of 1 day was chosen, since during this time at least one complete production cycle has time to complete in the longwall. The duration of this cycle significantly exceeds the value of the maximum measurement interval ∆tβ = 30 min., for which it is still advisable in practice to determine the modes of movement of air and gas through the mined-out and bottom-hole space of the production area. The research results are recommended for use in the design of efficient air supply schemes in the mining areas of coal mines and the correct placement of regulators to take into account the concentration of methane in the flow of consumed air.
Objective. The purpose of the research is to assess the indicators of aerological risk in the development workings of highly gas-rich coal mines. Introduction. The results of a retrospective analysis are presented, substantiating that the vast majority of explosions of dust-methane-air mixtures occur in development workings, and 63.8% of their gassing with methane to explosive concentrations is associated with ventilation disorders. Methodology. The assessment of aerological risk consists in the calculation of some indicators that reflect the measure of danger, in which an accident may occur, caused by the excess of the values of the mine atmosphere parameters in comparison with the normative ones. Indicators of the main hazards and vulnerability of ventilation schemes and methods make up the general structure of risk in development workings. Results. The methodological bases for assessing and forecasting the aerological risk of accidents in development workings are presented. A formula for calculating the predictive indicator of aerological risk is given. In accordance with the methodology, it is possible to quantify the reduction in the level of aerological risk when managing outgassing with the help of degassing. Discussion. Calculations have shown that the schemes and methods of ventilation of dead-end workings, in which there is a large degree of influence of the activity of mixing gases in the bottomhole zone and a small degree of influence of the exhaust gas zone on ventilation, are the most effective, with a normal level of safety. The values of the predicted upper-air risk indicator reach unity for the schemes and methods of ventilation of dead-end workings with a low degree of gas mixing activity in the bottomhole zone and a high degree of influence of the exhaust gas zone on ventilation, which indicates an extremely high level of explosiveness. Conclusions. Application of the developed methodology allows not only forecasting aerological risks during design, but also justification of aerological safety.
Introduction. Sustainable development of regions with high subsoil use demands performance improvement in gas cooling at compressor stations of main gas pipelines and environmental safety. Low energy prices specified the design parameters of gas transmission units throughout the boost of the gas industry. Therefore, the crucial task is to enhance the economic efficiency of main gas pipelines. One of the most energy-intensive units here is the cooling system of transported gas, which enables the reduction in operating costs. Gas air-cooling units used for cooling transported gas flow have spread significantly being notable for their increased energy output. Simulation methods of fan system parameters in gas air cooling units are assuming great importance in a rapidly globalizing world depending on their specific speed. Research objective. This study aims to develop a simulation model and guidelines on the construction of fans with high specific speed comparable cost-effectively to industrial fans. To support business objectives it is essential to specify the principles of cost-efficiency variation from that of specific speed, the influence of geometric and kinematic parameters, to conduct an experimental investigation to verify the results. Materials and methods. The research was based on a hypothesis for the consistency of the ratio between the pressure loss in a fan and the specific energy of transferrable air. Aerodynamic efficiency was accepted as a criterion for a fan local efficiency in order to determine the dependency of fan cost-effectiveness against its specific speed. Basic equations of fluid mechanics and theory of optimization were used as research mathematical tools. Results and discussion. In this study, we have established the influence pattern of the structural elements of a fan air duct and its geometrical parameters on the efficiency over a wide range of alterations of specific speed. We have obtained a mathematical model of correlation between geometrical and kinematic parameters of fans and their cost-effectiveness in a function of specific speed and residual flow swirl. The study has proved that it is essential to improve the aerodynamic quality of impeller airfoils and reduce the aerodynamic drag of air duct elements with the increase in specific speed of fans to extend their cost-effectiveness. Conclusion. The research described in this paper confirms the commercial importance of utilizing fans in air-cooling units according to aerodynamic configurations with a single wheel “K” and high specific speed ny ≥400, as far as they provide the highest possible aerodynamic efficiency at minimum weight dimension characteristics. The paper shows the capability of designing aerodynamic configurations of fan units of high specific speed ny ≥ 400 with the efficiency ≥ 0,85 where ԑy ≤ 0,2 achieves aerodynamic efficiency of impeller sections К ≥ 25. It has been established that the optimal region of theoretical pressure coefficient of fan units with a specific speed 380≤ny≤450 is located in the range 0,02<ΨТ <0,08. We have determined that when the aerodynamic drag coefficient of an air duct of a fan unit is equal to ԑy ≥ 1,2, its efficiency declines by more than 25 percent relative to ԑy ≤ 0,1. The authors have designed an aerodynamic scheme and produced an industrial prototype of a fan unit OGM VU 2.7-1.2 K3 with OV- 121TOH airfoils.
Ensuring the sustainable development of mining territories is impossible without the rational use of natural resources – minerals during their extraction and primary processing. So, at the stage of mining operations, it is necessary to establish the normative value of losses and dilution of minerals. This value is determined taking into account mining and geological, technological, economic, organizational factors. The normative value of losses and dilution ensures the maximum possible economic effect from the applied geotechnology and primary processing of recoverable reserves. In addition, in order to implement full-fledged rationing, it is necessary to identify the main types of losses and dilution and establish the causes of their formation. The researchers found that the normalization of recovery indicators is possible in the case of searching for the level of losses and dilution at the contact of the deposit, that is, when these indicators are interdependent. For the conditions of most deposits with almost any method and system of development, this is the only type of normalized losses and dilution. The only exceptions are underground mining systems with the collapse of ore and host rocks. All other extraction indicators are determined analytically, experimentally, statistically, by direct measurement. For the conditions of development of the Novo-Uchalinsky deposit by underground geotechnology, the main types of extraction indicators are identified, their causes are established, recommendations are given for determining their magnitude and rationing. Thus, losses in the array and in the beaten form are highlighted, such as losses due to the complexity of the contact and in the corners of the camera, losses on the bottom of the camera and in the baseboards. Dilution occurs in the following types – from the complexity of contact, vaulting in the roof of the chamber, laying on the side of neighboring chambers, from mixing rock in rock dykes. Rationing is carried out by losses and dilution due to the complexity of the contact, in addition, it is possible to normalize dilution by laying on the side of neighboring chambers, since it is possible to establish the optimal contour of the projected chamber on contact with neighboring laid ones. Losses in the corners of the chamber, “in the baseboards”, dilution from vaulting in the roof of the chamber are determined analytically; losses on the bottom of the chamber, dilution by laying from neighboring chambers – experimentally; by direct measurement by geophysical methods, the parameters of the dikes of empty rocks are determined to establish the amount of dilution from mixing the rock in the rock dikes. The actual level of losses and dilution of ore after the mining of the dredging unit is provided equal to the standard with strict execution of the development system and technology of the main production processes.
The relevance of the work is explained by the need to improve the quality of metal raw materials for the production of products with special properties, for example, in mining when leaching metals from ores, allowing to increase the extraction of components with a higher content in concentrates while minimizing the content of impurities. The purpose of the work. Substantiation of the possibility of changing the structure and properties of samarium titanate powder by processing in a spherical planetary mill "Activator 2S" due to the need to increase the purity of powders. Research methods: systematization, generalization and analysis of theoretical and experimental studies. To study the properties of samarium titanate, the following methods were used: scanning electron microscopy, X-ray phase, chemical, low-temperature nitrogen adsorption, X-ray phase analysis, spectral and atomic absorption with the processing of the results by methods of mathematical statistics. Results. The results of the study of the structure and properties of samarium titanate powders obtained by mechanochemical synthesis using a spherical planetary mill are presented. It is shown that the elemental composition of the mechanochemically synthesized charge corresponds to the stoichiometric content of titanium oxide and samarium. Quantitative values of activation parameters are given. The time of transformation of the initial oxides into nanocrystalline samarium titanate has been determined. The phases of the transformation of samarium titanate from an amorphous state to a crystalline state under the influence of temperature are differentiated. The properties of the samarium titanate powder obtained by mechanosynthesis are given. The possibility of obtaining nanoamorphic powder of samarium titanate by mechanochemical treatment of samarium and titanium oxides of the desired condition is proved.
Purpose. The article is devoted to the approbation of a computational methodology for analyzing the strength characteristics of a section of a scraper conveyor, taking into account the external impact on the section from elements of a mine treatment complex used in coal mining. Elimination of structural defects of the section is carried out, as a rule, by simple means of increasing the size of its elements. The presence of a generalized technique for analyzing the strength of the conveyor section ensures a rational choice of materials and geometric elements of the section at the design stage. Methods.The developed method of analysis of the stress-strain state of the section of the scraper conveyor is based on the application of the method of finished elements, which is the basis of automated systems of engineering calculations. The created design model of the section makes it possible to determine the strength characteristics of the structure depending on the operating conditions and the external system of forces caused by the interaction of the section with other elements of the mining treatment complex. Results. Based on the results of the conducted research, a plan has been drawn up to optimize the design of the conveyor section, the implementation of which ensures an increase in structural strength and, consequently, an extension of the service life of the conveyor. The obtained results of computer calculations are quite correlated with production data on the assessment of the failure of conveyor sections as a result of the destruction of structural elements. Conclusions. The developed computer model of the section of the scraper conveyor, when implementing the proposed methodology for analyzing the strength characteristics of the structure, ensures the selection of rational geometrically and technological parameters of the section at the design stage.
The author's work consists in developing a system for improving the quality of the educational process at the university and effective mechanisms for its control, as well as in building a system of mutually beneficial cooperation with leading partners in the mining and metallurgical industry. To achieve this goal, various methodological techniques were used, such as analysis, a systematic approach and a comparative legal approach. These techniques were implemented in relation to the technical universities located geographically in the mountainous regions. As a result of the conducted scientific analysis, approaches are proposed that, in our opinion, will improve the quality of education in the technical universities leading close cooperation with industrial partners in various fields and industries, including mining and metallurgy. The value and significance of the results lies in the attempt to implement and test the described approaches and evaluate the preliminary results obtained in technical universities located in the mountainous areas.
The current state and prospects of agricultural development in the Central Asian countries are considered. It is shown that demographic factors and food security are the main stimulating factors for the further development of agriculture. The acceleration of the melting of glaciers in Central Asia stimulates the search and development of progressive and water-saving irrigation technologies. The problem of the impact of large and medium-sized reservoirs on the microclimate and crop yields with the increasing development of the hydroelectric potential of the region becomes relevant. The chemical composition of irrigation water is a key factor in the preservation of soil structure and the development of crops, and the movement of chemical elements through the functioning of the water-soilplant chain can harm the health of the population.
ISSN 1998-4502 (Print) ISSN 2499-975Х (Online)