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Automated control system phlegmatization of explosions of dust-methane-air mixture in the mine atmosphere

Nikolay I. Abramkin, Pavel A. Mansurov, Alexandra V. Kuzina

Introduction. The work presents a general and principal diagram of the control system, provides recommendations for the choice of a set of technical means of practical implementation of the system and justification of the application and parameters of various sensors, power supplies, controller, communications, signal converters and actuators, which use different methods and methods of processing signals of different nature, which ensures completeness and prevents distortion of signals and parameters that affect the quality of the automated system of phlegm The aim of the work is to develop and implement the technical support of an automated control system of phlegmatization explosions of dustmethane-air mixture in the mine atmosphere. Materials and methods of research. To achieve the goal of controlling phlegmatization of dust-methane-air mixture explosions in the mine atmosphere, the search and analysis of materials on this topic is carried out, an automated control system is developed and observation of its work in real conditions is made. Research results. The dependences of the upper and lower thresholds of explosiveness of dust-methane-air mixture, as well as the achievements in the study of the molecular structure of water and methane can assess the effectiveness of measures to prevent methane and dust explosions in coal mines and propose a patentable method of phlegmatization of methane explosions in coal mines. Discussion. At a choice of CTS the basic attention is given to reliability of functioning of measuring techniques, standardization of interfaces, software of controllers and processors, on the basis of which it is supposed to develop software and realization of algorithmic and mathematical maintenance of the automated control system and its debugging in industrial conditions. Conclusion. The studies have shown that the sequence of installation of nozzles along the length of the face, should not exceed 1/5-1/7 of the length of the mini-drops falling (if a weighted mini-drop falls for 6-8 seconds, at a speed of 2.5 m/s, it flies 15-20 m, and, therefore, nozzles should be set every 12-15 m). Resume. At successful approbation and positive results of the automated control system of phlegmatization of explosions of dust-methane-air mixture in a mine atmosphere it can be successfully included in the existing systems of gas protection, extending their functions and increasing the level of industrial safety of mines. Also, studies have shown that for the implementation of a phlegmatization control system of explosions of dust-methane-air mixture in a mine atmosphere to increase the accuracy it is necessary to increase humidity, which in turn leads to the need to choose the location of installation of nozzles. Suggestions. In real conditions the level of absolute moisture of 16 g/m3 is possible at a temperature not lower than 22 °C and relative humidity of not less than 90 %, therefore, the task of the automated control system of phlegmatization of dust-methane-air mixture explosions (ACS FVPS) in the mine atmosphere is to maintain the maximum absolute humidity at the existing humidity and temperature in the clearing or preparatory face, taking into account the methane and dust concentration in the mine atmosphere.

Number of views: 18

Analysis and comprehensive evaluation of gas-dynamic processes in coal mines using the methods of the theory of probability and math statistics analysis

Igor I. Bosikov, Roman V. Klyuev, Valera N. Khetagurov

Introduction. The article discusses the technical distribution system of gas-dynamic and aero-dynamic processes in coal mines, characterized by: the uniqueness of modes, linearity, dynamism, variability of parameters and variable operating conditions. An analysis and a comprehensive assessment of gas-dynamic and aero-dynamic processes in coal mines is being carried out. Research tasks: to develop a methodology for the analysis and comprehensive assessment of gas-dynamic and aerodynamic processes in coal mines using the methods of mathematical statistics and probability theory. Research objectives. Conduct an analysis of gas-dynamic and aero-dynamic processes in coal mines. Results of the research. The dynamic properties of ventilation objects in normal operation can be described by integrodifferential equations. Analysis and evaluation of experimental data on the distribution of gas-dynamic and aerodynamic processes confirmed that the technical air supply system for coal mines is a dynamic link with an inverted effect. The developed methodology for the analysis and comprehensive assessment of gas-dynamic and aerodynamic processes in coal mines using the methods of mathematical statistics and probability theory made it possible to obtain a generalized expression for the transfer functions of ventilation objects, taking into account the delay, and to describe the dynamic properties of mining sites under various ventilation modes. It has been experimentally established that the linearized dynamic characteristics of mining sites in the ventilation mode, when the transient gas-dynamic process has the form of a «burst» of methane concentration, can be described by integro-differential equations.

Number of views: 15

Evaluation of shock pulses energy in the grinding rocks process for various types of mills

Yuri V. Dmitrak, Viktor A. Atrushkevich, Sergey S. Kubrin, Ludmila S. Adamova

The article presents the results of theoretical studies describing the process of crack growth during the processing of rocks in mills. The mathematical apparatus of the theory of oscillation of round plates is used to determine the energy parameters of the crack propagation process. An expression is found for identifying the energy of deformation of the crack wall as a result of impact. The parameters of the shock pulse acting on the crack wall are determined. The value of the impact energy necessary for the destruction of the rock has been established.

Number of views: 19

Interrelations between technological processes of open-pit mining

Sergey N. Zharikov, Vyacheslav Al. Kutuev

Introduction. High productivity in mining processes is possible only with sufficient consistency between mining processes: drilling – blasting – excavation – transportation. The relationships between drilling and blasting processes are most well studied, although there are also a number of issues related to the interpretation of data and the choice of efficiency criteria. The further link between blasting by excavation and transportation is incomplete, therefore, there is no clear direction of systematic and coordinated cost optimization in the mining processes. Getting efficiency in one process can lead to inefficiency of adjacent processes. Therefore, it is desirable that the criteria for the efficiency of work were universal and, at the same time, could reflect the individual specifics of the process. The purpose of the research. The purpose of the research was to establish links between mining processes by taking into account their energy characteristics. Research methodology. In the course of the research, modeling of the processes of drilling wells, explosive destruction, and excavation was widely used. Methods of mathematical statistics, system analysis, synthesis, modeling and field experiments were used to identify the relationships. Model representations were compared with practical data and boundary conditions were specified. Research results. As a result of the research, a universal characteristic of the process has been established, which is the energy consumption per 1 cubic meter (J/m3 ). In the case of drilling and blasting geometrically, these are the energy costs spent on destroying the volume of rock beaten off by one well. For excavation, this is the energy for excavation and loading of rock mass, the properties of which are dependent on the energy of explosive destruction and the quality of the explosion, characterized by the geometric parameters of the collapse and the intensity of excavation work. Conclusion. It is revealed that the establishment of energy relationships between the extraction processes allows not only to evaluate their efficiency, but also opens up the possibility to regulate the specified loading intensity by calculating the number of cycles required for the face and timely delivery of the appropriate number of vehicles, and can also be the basis for more accurate statements of optimization problems, including taking into account anisotropy the mountain range and the variety of influencing organizational and technological factors of mining operations. It is advisable to develop further research in the direction of processing, as suggested by I. A. Tangaev. To link the energy parameters of drilling – blasting – excavation – transportation – crushing – crushing. Considering that modern systems of dispatching and monitoring of mining machines allow collecting real-time information from sensors of the main nodes of working mining equipment, and network technologies allow tracking this in real time, then matching energy costs in processes, or changing their balance, allows you to quickly identify the efficiency or inefficiency of work. This can significantly affect the practice of making managerial decisions.

Number of views: 19

Development of a hybrid model for predicting the consumption of electrical energy for a mining and metallurgical enterprise

Svetlana A. Vyalkova, Angelika D. Morgoeva, Oksana A. Gavrina

Introduction. Reducing the energy intensity of production is one of the directions of development of enterprises, regions, states, as it affects the level of economic development and environmental well-being. One of the methods that contribute to the rationalization of the use of electric energy is forecasting. The purpose of the study is to develop a model for forecasting electricity consumption, which allows obtaining a reliable forecast of electricity consumption. To achieve this goal, an analysis of literary sources reflecting the current trends of predictive analytics in solving the problem of forecasting electricity consumption was carried out. Materials and methods of research. Singular spectral analysis and deep learning algorithms (multilayer perceptron) were used in the work. At the initial stage of the study, a model of a fully connected neural network (multilayer perceptron) was built, the prediction accuracy of which was more than 94%. Then the algorithm of singular spectral analysis was implemented, and the initial time series of power consumption was decomposed into additive components. The resulting decompositions were used to create a hybrid forecasting model. Research results. A number of experimental studies have been conducted that meet the goal of developing models that most accurately approximate experimental data. The result of the study are two forecasting models: an artificial neural network model and a hybrid model that includes a singular spectral analysis to decompose a number of power consumption into trend and harmonic components and an artificial neural network to predict them. Discussion. With the help of the hybrid model, an accurate result was obtained – the average absolute percentage error for the year is 4.04%. Forecasting was carried out for a year (by months) using data from the previous two years as a training subset. The neural network model provides less accuracy in predicting power consumption over 12 months compared to the hybrid model. Conclusion. Thus, the use of singular spectral analysis made it possible to reduce the magnitude of the forecast error by almost 1%, which confirms the effectiveness of the method and the relevance of the development of hybrid forecasting models. Resume. As a result of the conducted research, it was revealed that one of the most popular and effective forecasting methods is singular spectral analysis and the use of various deep learning algorithms. The developed hybrid model of electric energy consumption for a mining and metallurgical enterprise allows you to build a forecast of electricity consumption, the accuracy of which is more than 95%. Suggestions for practical application and directions for future research. The research results can be useful in the process of production management, since an accurate forecast of electricity consumption is important when planning production, scheduling equipment repairs and maintenance of the electrical network. The prospect of further research is to increase the forecasting horizon, the volume of the initial sample and taking into account additional factors characterizing the technological process.

Number of views: 19

Assessment of the degree of influence of the solid phase of mine wateron the durability of the hydraulic foot assembly of the sectional pump of the main drainage plant of the Udachny mine

Nickolay P. Ovchinnikov

Introduction. The main factors, which negatively influence on durability of balancing ring of sectional pump, are presented. Object of study. The sectional pumps of the dewatering facilities of the kimberlite mine “Udachny”. The purpose of the research. Assessment of the mine waters solid phase influence degree on balancing ring durability of sectional pump to clarify the expected technical and economic effect of penetration of an additional clarifying tank in the conditions of the main drainage of the kimberlite mine “Udachny”. Research methodology.The results of inspections of the failed balancing rings allowed to establish the main types of their damage. Next, according to the results of analytical researches main factors were determined, which are accompanied with loss of operability of balancing ring. Then, with the help of correlation and regression analysis degree of influence of each of the factors on the durability of balancing ring was estimated. Research results. According to the visual inspection, the hydroabrasive wear is most strongly manifested in places of contact friction of parts of the balancing ring unit.It has been found that the life of the balancing ring unit of the sectional pump with the smooth start of a separately taken water drainage plant can be calculated as a linear function of the conditional intensity of the hydro-abrasive-adhesive wear of its parts, which is the product of the concentration of mechanical impurities in the mine waters and the wear resistance coefficient of the metal, which takes into account the total operating time of the pump in transient modes. In the underground development of kimberlite ores, the service life of the balancing ring unit is primarily determined by the pressure developed by the sectional pump. At the kimberlite mine “Udachny” of PJSC ALROSA, where there is a maximum concentration of mechanical impurities in the mine waters under the conditions of the main water drainage, the additional clarifying reservoir is driven by a useful volume, which significantly exceeds the operating water-collecting mining workings.The inclusion of this clarifying tank in the current process chain for clarifying mine waters will significantly reduce the content of solid phase in them, which in theory should positively affect the durability of the components of the flow part of the pumping equipment, including the balancing ring unit.

Number of views: 17

Application of drilling machines with impact cam mechanism in various mining and geological conditions

Anna V. Teplyakova, Ivan Al. Zhukov, Nikita Vl. Martyushev

Purpose. The article is devoted to the search and analysis of well-known technical solutions of drilling machines equipped with a cam impact mechanism, according to the results of which fundamentally new scientific tasks are set related to the substantiation of the design parameters of the impact unit of the drilling machine, providing the possibility of automatic adaptation of drilling modes in changing mining and geological conditions. Research methods. To implement the impact of the tool on the rock, a cam mechanism is built into the design of the machine, which provides the generation of a given impact energy. Cam mechanisms are represented by a wide variety, among which the most suitable for equipping impact drilling machines is a cylindrical end cam mechanism in which the leading link – the cam performs a rotational movement, converted into a reciprocating motion of the output link – the pusher-striker. Rational cam profiling makes it possible to implement a certain law of pusher motion with a sufficient degree of accuracy, and, consequently, to solve the problem of choosing the optimal impact energy. Research results. Based on the results of the critical analysis of the structural schemes of the above machines and mechanisms, new research tasks are being set for science and practice, the implementation of which will allow obtaining new scientific knowledge in the field of the use of cam mechanisms in impact drilling machines. Conclusions. The use of impact cam mechanisms of a special structure and geometry makes it possible to realize the idea of creating a drilling machine capable of automatically adapting operating modes to operational mining and geological conditions.

Number of views: 19

Analysis of conjugate heat and mass transfer during aerosol flotation of gold from placers

Sergey I. Evdokimov, Tatiana Е. Gerasimenko, Ruslan N. Maksimov, Yuri G. Klykov

Introduction. The probability of replenishing the SME of placer gold by registering the reserves of new deposits is low, and the involvement of man-made waste in the economic circulation will allow maintaining the achieved level of gold production from placers for 10-15 years. Purpose of research. The aim of the study is to develop a technology for extracting gold from old wastes of alluvial mining based on the identified patterns of conjugate heat and mass transfer during aerosol flotation of metallic gold. Methodology. For the development of technogenic wastes of alluvial gold mining, an enrichment module based on gravity and flotation methods has been developed. The module equipment has passed research tests in industrial conditions. During flotation, the increase in the gold content in the operation of the main flotation is carried out by mixing the crude concentrate isolated from ½ of the original feed with the other ½ of it. A mixture of air and hot steam was used as the gas phase during flotation. Research results and discussion. The temperature difference at the gas-liquid interface is the driving force of the vapor-liquid phase transition with the release of significant condensation heat. The time of particle sticking to the bubble is commensurate with the time of heating the interfacial surface due to the heat of vapor condensation. This allows us to consider temperature as one of the reasons for changing the result of flotation by a mixture of air and water vapor. Due to vapor condensation, the bubble size and the intensity of interfacial heat transfer decrease. When the minimum size is reached, overheating of the vapor in the bubble leads to an increase in the evaporation of the solvent and pressure in the gas phase: the heat transfer between the phases and the size of the bubble begin to increase. Transient processes in steam are non-polytropic and the limiting bubble sizes decrease with time: at the minimum size and maximum temperature, the heat transfer of steam is higher than the heat transfer of water with an increase in the size of the bubble and a drop in temperature in it. The limiting transitions of the bubble size are the cause of high-speed oscillations of the bubble walls, which decay with time. When the bubble surface is stretched in the three-phase contact zone, the gas-liquid surface tension increases due to a decrease in the density of the adsorption layer of surfactant molecules, which causes an increase in the force holding the hydrophobic extractable particle on the bubble surface. Radial tensile-compression deformations lead to shedding from the bubble surface of hydrophilic gangue minerals randomly retained by the bubble surface (for example, in the case of high occupation of the bubble surface by extracted particles). Conclusion. It is substantiated that the combined gravity-flotation technology is economically justified: the added value of marketable products provides an increase in the value of the net present value and the return on investment index, and a reduction in their payback period. It has been proven that the addition of gravity technology with flotation methods for extracting gold provides an increase in annual metal production by ~27% rel. due to the additional extraction of forms of gold that are “resistant” to gravitational methods.

Number of views: 231

Natural parks, balneological resources аnd rural development

Irina P. Glazyrina, Nadezhda V. Pomazkova, Oksana Ts. Darmaeva

Introduction. One of the priority directions in the field of environmental protection is the construction of models for the development of the territory designed to combine the interests of nature conservation and sustainable development of territories, including the development of environmentally friendly industries and the dissemination of experience in sustainable environmental management practices. The availability of balneological resources enhances the attractiveness of the territories and can be an additional source of income for the local population. One of the ways to solve these problems is to include them in specially protected natural areas, and this strategy often brings good results and contributes to the "green" growth of the local economy. This is evidenced by numerous examples in Western Europe and North America and, to some extent, this is also the case in Russia. However, experience shows that this does not always meet expectations, and it is not enough to give the territory the status of a park. The purpose of the research. Using the example of the Arey Park in the Trans-Baikal Territory, to identify the reasons for the failures of attempts to use the European experience of natural parks in the eastern regions of Russia as factors for the development of a "green" economy in rural areas. We are considering the experience of creating a nature park in 2013 in order to protect the ecosystem and use the valuable balneological resources of Lake Ares in accordance with the goals of the "green" economy. Research results. The paper shows that, despite some improvements in the state of the coastal ecosystem, the status of specially protected natural areas (protected areas) does not contribute to achieving the originally set goals. Its balneological resources, including therapeutic mud, are used uncontrollably in the shadow sector, which does not guarantee either effective treatment or environmentally safe withdrawal. Similar problems arise for other forms of recreational services when organizing campsites, arranging hotels and food outlets. Therefore, the park practically does not realize its potential either as a driver of the growth of the local economy or for the effective use of balneological. The authors analyze the causes of the processes taking place and also propose a number of measures to involve the natural resources of parks in the local economy in such a way that their use brings economic benefits to the local population, while maintaining high environmental quality.

Number of views: 224

On the determination of buildings technological deformations in geotechnical construction

Elena Yu. Kulikova, Dmitry S. Konyukhov

Objective. The purpose of this work was to determine technological deformations and identify their causes during mining and construction work. Introduction. The modern world is characterized by the expansion of the scale of underground construction, which has a large arsenal of advanced technologies, tunneling equipment, etc. In urban conditions, underground construction is carried-out in the zone of influence of existing land development. At the same time, due attention is not paid to the technological deformations of the existing development. Methodology. Analysis of the results of experimental and practical geotechnical monitoring shows that any technologies of underground construction in conditions of dense urban development cause “technological deformations” of existing buildings, significantly (40-90%) affecting the safety of buildings in the process of new construction. They depend on the mining and hydrogeological conditions of the construction site, the quality of work, the type of enclosing structures of the pit and equipment used. Concomitant reasons are parameters such as the length of the gripper during construction by the trench “wall in the ground” method, the density of bentonite suspension, the distance between the trench and the foundation of the building, the load on the base of the foundation. In the medium technological sediment with the open method of work is estimated at about 60% of the total fixed value. Results. Technological deformations depend on three groups of factors: external, design and technological. External factors include engineering-geological and hydrogeological conditions of the construction site, as well as the stressstrain state of the soil massif. Design factors cover the space planning and design parameters of the constructed structure, which have an impact on the technology of work. Discussion. Technological factors determined by the characteristics and technological features of the equipment used, technological parameters of work production and quality control of their performance. In this regard, in order to provide feedback between the quality control of geotechnical construction and the safety of the surrounding development, it seems appropriate to understand under the term “technological deformations” deformations of the foundations, foundations and structures of buildings from technological influences in the construction process. Conclusion. In the presented work, the factors and parameters affecting the magnitude and scale of technological precipitation are highlighted. On this basis, proposals have been formulated for the elaboration of the concept of “technological sediment” in order to effectively control the quality and ensure the safety of the underground works carried out.

Number of views: 222
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ISSN 1998-4502 (Print)                                                            ISSN 2499-975Х (Online)