The Arctic zone of Russia is a territory where such minerals as gold and other precious metals are concentrated. Most often, the development of such deposits is carried out by an open method. The conditions hindering its use should be considered: the depth of distribution of permafrost and significant amplitude of changes in atmospheric air temperature during the year, month and day. The consequence of the alternation in depth of temperature zones may be the formation of recirculation zones in which harmful substances accumulate. Purpose of work. Study of the formation of velocity and temperature fields in a quarry under natural ventilation, taking into account the complex dynamics of atmospheric air temperature. Research methods. Systematization, generalization and analysis of theoretical and experimental studies in this area, including those carried out at the considered fields. Analysis of the results of mathematical modeling of aerodynamic processes in a quarry. Results. It is noted that to assess the peculiarities of formation of the mine atmosphere parameters it is sufficient to carry out only mathematical modeling of aerodynamic processes allowing to define the conditions of temperature inversions formation and dimensions of recirculation zones being potentially dangerous for accumulation of pollutants. The methodology of aerodynamic processes modeling taking into account the geometry of the pit space, temperature gradient, speed and direction of the wind flow is proposed. It is shown that at positive and negative temperature differences for the two investigated air media the development of recirculation movement zones of air masses that assure the accumulation of pollutants which in turn leads to reduced efficiency of natural ventilation in the pit, is characteristic. The conclusion has been made on the necessity to apply additional engineering measures during the period of inversion formation with negative temperature gradient in order to normalize the pit air parameters.

Introduction. The constant increase in the consumption of mineral resources leads to the depletion of available reserves and a sharp increase in the depth of field development. In addition, reserves that were previously classified as off-balance sheet and the development of which is economically inefficient at the time of the assessment of technical and economic calculations are involved in the development of minerals: low metal content; location within water protection zones, settlements, structures, agricultural facilities, nature reserves, monuments of nature, history and culture. Involvement in the development of areas of deposits with a low content of a useful component in ore increases the costs of extraction, transportation and processing, as well as the formation of more man-made waste. The main way to ensure the sustainable development of the mining region is the use of mineral deposit development systems with a hardening bookmark and the involvement of man-made waste in a closed production cycle. The use of geotechnology with a bookmark helps to increase the completeness and quality of the extraction of reserves of the deposit, protects the hydrogeological regime and reduces the degree of crack development in the underworked array, which leads to the preservation of the water-proof thickness and protects the daytime surface from collapse. Geotechnology with a bookmark allows you to work out previously abandoned targets, which increases the mineral resource base of the mining enterprise and increases the life of the mine and allows you to solve the social issue of the region where the mining enterprise is the city-forming. The use of man-made waste from mining and processing and metallurgical enterprises in the preparation of the laying composite leads to their disposal. Utilization of man-made waste with geotechnology with a bookmark leads to a decrease in the volume of man-made storage facilities, which reduces the cost of their creation and maintenance. All this contributes to the implementation of the concept of waste-free production, the integrated development of natural and man-made resources, the sustainable development of the mining region and the reduction of the impact of mining and metallurgical industries on the environment. Purpose of research. Introduction of technologies that ensure the completeness of mineral extraction and safe mining operations with minimal environmental impact. Research methods. G eneralization of theoretical and experimental studies carried out by scientists in this field, synthesis of literary and patent data, analysis and summary of previously performed own research, comparison of theoretical calculation data on mathematical models with the experimental results obtained, application of current state standards, approved research methodology, use of calibrated and serviceable equipment. Materials were activated in a DESI-11 laboratory disintegrator, compression samples were tested on a PI-2000-A test press, and the reliability was confirmed by the repeatability of the results with a sufficient number of experiments. Research results. The possibility of replacing the traditional components of the laying composite with man-made waste without loss of regulatory characteristics and improvement of its rheological properties is substantiated. The necessity of applying mechanical activation treatment of the components of the laying composite in order to improve its rheological characteristics and the strength of the array after solidification is proved. The demand for resource-reproducing technologies that allow the most complete use of the technogenic mineral resource potential of the mining and processing enterprise, which will lead to a multiplicative ecological and economic effect, has been confirmed. It is established that the sustainable development of the mining and processing region is impossible without highly eff

Introduction. Issues of formation of maximum expenses and their forecast, risk extreme flow rates on the rivers of Armenia represents a significant interest for consumers of water resources. The works of scientists of the Republic of Armenia are devoted to the solution of this problem: (Vardanyan T. G., Muradyan Z. Z., 2014), forecasting the maximum water flow for the Jermuk hydrological station on the Arpa River (Misakyan A. E., Azizyan L. V., Azizyan A. O., 2014), assessment of long-term fluctuations of the maximum runoff of rivers in the mountainous territories of Armenia in the context of global changes climate (Margaryan V. G., Ovcharuk V. A., Goptsy M. V. Borovskaya G. A., 2020). This paper analyzes the risks of extreme spring runoff river flood Arpa (Republic of Armenia) related to degree assessment the danger of flood waves. Problem solving can help prevent economic damage and loss of life, and raise issue of extreme runoff risk management. Unlike listed works, this study uses longer series of actual observations and a certain section of the river. Purpose of research. Assessment and management of hydrological risks during the period spring flood in the river basin Arpa. Methods. The work used the methods: of mathematical-statistical, extrapolation, analysis, analogy, correlation. Results. Correlations between the values of the modulus of extreme costs 1 and 10 % security and weighted average height drainage basin, as well as the relatively close relationship between the average values of extreme costs for the periods 2001–2020 and 1981–2000 biennium, integral curve of extreme flow rates of floods in the section Yeghegnadzor of the Arpa River. These dependencies can be used to preliminary estimates of the maximum runoff of the spring flood unexplored rivers of the considered territory. To manage and planning of extreme water resources, multifactorial dependencies that can be applied when making forecasts. The rate of extreme flow rates of the spring flood has been calculated, coefficients of variability (Cv) and skewness (Cs), absolute maximum costs of various security. Conclusion. Average values of extreme water flow rates of the river. Arpa for the period 2001–2020 mostly inferior or slightly higher than average values for the period 1981–2000. In the Arpa river basin from 1981 to 2020 year mainly there is a tendency of decreasing extreme river flow, that is, the degree of risk of extreme expenses.

As a result of coal mining, the natural landscapes of the Kemerovo region are involved in the process of global
technogenic transformation. As a result of open-pit coal mining, catastrophic changes occur in ecosystems, which are accompanied by the destruction of the litho logical basis, degradation, transformation and displacement of huge tracts of soil cover. The aim is to study agro physical, agrochemical, sanitary and epidemiological indicators of soil samples of technogenically disturbed territories of Kuzbass. Objects of research. Samples of the surface layer of the external rock dump of LLC "Korchakolsky Section" the dump rock and the surface layer of the nearby territory, of the forest belt of the processing plant of LLC "JV "Barzassky Partnership" and the Taldinsky coal mine. The samples of undisturbed lands selected near the museum-reserve "Tomskaya Pisanitsa" were used as a reference. Methods. Agro physical (hygroscopic humidity, wilting humidity, soil density, soil porosity) and agrochemical (water and salt pH, total alkalinity, hydrolytic acidity, sum of exchange bases, dry residue, content of Cl–, SO₄2–, HCO3–, NO3–, Ca2+,Mg2+, Al) analysis of selected soil samples, including the content of pollutants of anthropogenic origin. The sanitary and epidemiological indicators of the samples were studied. Methods of chemical and instrumental analysis (electrochemical, chromatographic, molecular absorption spectroscopy) were used for research. Results. The analysis of the degree of technogenic disturbance of the studied landscapes is carried out. Samples of LLC JV "Barzassky Partnership" can be attributed to sandy loam soils of a slightly alkaline type. The nickel content exceeded the MPC by 1.26 times; the BGCP index by 25.25 times. Samples of the Korchakolsky section are attributed to sandy soils of a slightly alkaline type. The content of mobile phosphorus exceeded the MPC by 3.40 times, zinc by 1.1 times, nickel by 1.22 times, arsenic by 2.15 times; the BGCP index by 29.41 times. The samples of JSC Taldinsky Coal Mine are classified as sandy loam with a neutral reaction. The content of the mobile form of phosphorus exceeded the MPC by 5.22 times; nickel by 1.5 times; arsenic by 1.67 times. The samples of the reference soil are attributed to clay soils of a slightly alkaline type. The content of the mobile form of phosphorus exceeded the MPC by 2.27 times; nickel by 1.17 times, the BGCP index by 62.62 times. Conclusions. Based on the analysis of the composition of dump and quarry landscapes of technogenically disturbed territories of the Kemerovo region, detoxification of soils with the use of biological reclamation is recommended. 

Volcano arabica coffee is one of the best coffee derived from Gayo Highlands, Aceh Province, Indonesia. That coffee was cultivated in a volcanic region, therefore as known as Gayo volcano arabica coffee. Several varieties from Gayo volcano arabica coffee were included Borbor, Timtim, and P88. Gayo volcano arabica coffee was a low caffeine coffee with a taste exceeding the Blue Mountain coffee from Jamaica which was determined using sensory assessment. This study aims to conduct a sensory taste assessment from Gayo volcano arabica coffee variety using the analytical hierarchy process (AHP) method. The AHP method is one of the easiest methods to produce an output calculated based on the input and weight value. Sensory assessment criteria have consisted the flavour, sweetness, aftertaste, body, and acidity. The preference for the best criteria based on the panellists was included taste (0.280), then the sweet criteria (0.253), after tasting (0.212); body (0.140); and acidity (0.115). The estimation was tested with a consistency ratio under 0.1 (10%). The results of the sensory assessment of the acceptance of Gayo volcano arabica coffee products showed that the P-88 variety with full-wash processing (0.206) was the product with the highest approval. Then followed by the Borbor variety with full-wash (0.176) and semi-wash processing (0.166), then the Timtim variety with semi-wash (0.166) and full-wash processing (0.164). The P-88 variety with semi-wash processing (P88) was the product with the lowest level of acceptance by the panellists. This finding was most important for the commercial development of arabica volcano coffee in the future. The varieties associated with the highest acceptable taste became the better necessary varieties to cultivation and developt for farmers and agroindustry.

Introduction. The article discusses the design of an improved belt-wheel conveyor with an intermediate pinion drive. The use of such a belt-wheel conveyor eliminates the need to use mobile crushing units and intermediate conveyor loading devices. The transfer of the drive from the end sprockets to the intermediate ones installed on the lifting section of the conveyor route significantly reduces the efforts in traction chains and running rollers and reduces the volume of mining and capital works. The introduction of a planetary differential mechanism between both drive sprockets ensures an even distribution of the traction load between both traction chains. At the same time, the possibility of misalignment of the running supports and the associated increased wear of the running rollers is excluded. Conveyor transport is the most effective means for lifting rock mass. The fundamental difference between belt-wheeled conveyors is the exclusion of rolling of the load-bearing belt along stationary roller supports. The joint movement of the conveyor belt and the closed loop with running supports provide the possibility of moving large-lump mining loads with piece sizes up to 1200 mm or more, which eliminates the need for secondary crushing of loads in mobile crushing units. The purpose of the research: the use of an improved belt-wheel conveyor with an intermediate pinion drive for the transportation of large-sized cargoes. Research methodology. A comparative analysis of the designs and parameters of lifting conveyors was carried out in order to ensure non-overloading lifting of loads from deep quarries with a further increase in depth. Research results and discussion. As a result of a comparative analysis of the conveyor designs and parameters, the most optimal variant of a belt-wheel conveyor with an intermediate pinion drive using a planetary differential mechanism was established. Conclusions: 1. Studies of the design of an improved belt-wheel conveyor with an intermediate pinion drive have been carried out. 2. It is established that the introduction of a planetary differential mechanism between both drive sprockets ensures an even distribution of the traction load between both traction chains. 3 It was found that the transfer of intermediate drives of lifting belt-wheel conveyors from the head end sprockets to the sprockets installed on the upper section of the bend of the conveyor route can significantly reduce the load on the traction chains and running rollers of the supports. 4. It is determined that the transfer of the drive from the end sprockets to the intermediate ones installed on the lifting section of the conveyor route significantly reduces the efforts in traction chains and running rollers and reduces the volume of mining and capital works. 5. It is confirmed that the introduction of a planetary differential mechanism between the shafts of the drive sprockets ensures a uniform distribution of the drive force between the two traction chains, excluding the possibility of misalignment
of the running supports and the associated increased wear of the running rollers.

Introduction. As the actual data show, the safety of coalmines is the most vulnerable in the event of explosions
of methane and coal dust, often accompanied by a complex manifestation and implementation of several hazardous factors, such as gas, dust, exogenous fires, leading to catastrophic consequences. To assess, predict, manage and reduce the consequences of the complex implementation of dangerous aerological factors in the occurrence of accidents in coalmines, a methodology has been developed for assessing and managing aerological risks in coalmines, based on the hierarchical structure of aerological risk. Objective. Assessment, forecasting, management and reduction of rank III aerological risks for extraction areas and development workings of highly gas-rich coalmines. Methodology. To assess, predict, control and reduce the consequences of the complex implementation of hazardous production factors in the occurrence of accidents associated with explosions of gas and dust in coal mines, a methodology has been developed for assessing and managing aerological risks in coal mines, based on a systematic approach in accordance with the hierarchical structure of aerological safety. The aerological safety of mines can be quantified in terms of aerological risks: the lower the risks, the higher the safety. All aerological risks were divided into three ranks according to their importance in the production activities of the mine, corresponding to the hierarchical structure of the aerological safety of the mine. Aerological risks of the I rank are understood as aerological risks covering the entire mine, aerological risks of the II rank cover layers, wings, deposits; aerological risks of III rank cover separate mining or development sites. Comparison of mines by aerological risks should be made according to aerological risks of the same rank. When performing research, an analysis of literary domestic and foreign sources was used; generally accepted methods, including methods of mathematical statistics and probability theory; a method of expert assessments to obtain the values of the hazard and vulnerability coefficients of ventilation methods for excavation areas and development workings. Results and discussion. A methodology has been developed for constructing a hierarchical structure of aerological risks in coal mines. A block diagram of aerological risks of III rank has been compiled, including the main hazards in the excavation areas and development workings and the main types of vulnerability of the ventilation schemes of the excavation areas and the methods of ventilation of dead-end workings. Calculations have shown that when developing the most dangerous mine seams, the lowest values of aerological risk of III rank for excavation areas are characterized by combined ventilation schemes in the absence of a diagonal connection in the scheme; the presence of an unstable diagonal connection in the ventilation scheme of the excavation area increases the aerological risk by 2.7 times. For development workings carried out along seams prone to rock bumps, spontaneous combustion, sudden outbursts of coal and gas, with a specific dust emission of more than 1200 g/t, only ventilation methods with a high degree of gas mixing activity in the bottomhole zone can be applicable. Conclusions. The developed hierarchical structure of aerological risks makes it possible to rank risks by levels and compare risks of the same rank. The application of the developed risk assessment methodology makes it possible to predict and reduce aerological risks in the design and operation of coal mines.

Introduction. Currently, a large number of scientific, technical, technological and organizational studies are being conducted in order to reduce the cost of underground coal mining. This is due to a certain decrease in the cost of coal, both on the world and on the domestic market. It should be noted that the complex mechanized face of a coal mine is the beginning of the technological chain of underground coal mining, on which the activity of the entire coal mining enterprise depends. In addition, the growth of digitalization in other industries is pushing mining enterprises to implement modern digital solutions in their organizations. Therefore, special attention should be paid to modeling the operating modes of equipment for complex mechanized coal mine face. The purpose of the research is to build simulation models of the main technological equipment of a complex mechanized coal mine face with a sufficient degree of adequacy to real equipment. Research methodology. The article uses simulation modeling of equipment for complex mechanized coal mine face, presented in the Matlab software product (models of a dredging combine, a lava conveyor, a crusher, a loader). The Eickhoff SL-300 (option 4) acts as a prototype of the simulation model of the dredging combine, the prototype of the avalanche conveyor model is the FFC–9 Glinik conveyor, the prototype of the crusher model is the FLB-10G Glinik crusher, the prototype of the loader model is the FSL-9 Glinik loader. It should be noted that this equipment is installed at the excavation site of the Polysaevskaya coal mine of the Komsomolets mine Management of SUEK-Kuzbass JSC. The presented simulation models of the equipment of complex mechanized coal mine face allow you to set different values, both in electrical and technological parameters. Research results. As a result of the conducted research, simulation models of complex mechanized slaughter of highperformance coal with a high degree of adequacy were obtained. Conclusions. The proposed simulation models of the complex mechanized face of a high-performance coal mine will allow us to investigate the operating modes and optimize them according to the criterion of increased energy efficiency, which will affect the reduction of the cost of coal mining by underground method.

Introduction. The current stage of well construction is characterized by the complication of drilling conditions and casing of exploratory and production wells. The increase in the complexity of mining conditions is associated with both geological and man-made factors. The drilling technologies used in these conditions are not always efficient enough and do not provide the required level of drilling quality and well casing tightness. In this regard, there is a need to conduct research aimed at studying the non-stationarity of the hydrodynamic conditions of drilling, the possibility of controlling and managing these processes and changing the properties of drilling fluids. Purpose of research. Determination of the parameters of the strength of the walls of wells during drilling in difficult mining conditions of exploited oil fields. Methods of research. Theoretical and experimental studies of wall strength parameters are based on the principles of a systematic approach to solving complex engineering and scientific problems. The system approach used includes information support, organization and management of technological drilling processes. The controllable strength and insulation parameters of the formed screen are revealed, the regulation of which ensures the achievement of the goals of work on strengthening the walls of the well. Research results and discussion. Based on the results of the research, a method is proposed for strengthening the walls of the well in the process of deepening its bottomhole. To test the method, a site was selected that meets the requirements of the complexity of mining conditions: the eastern outskirts of the East European platform; the sedimentary cover is represented by various rocks, including fractured, weakly stable ones; The field currently in production is at an advanced stage of development. The wells planned for construction are reserve, designed to regulate the oil recovery system. The drilling of directional wells with a horizontal ending in these conditions was accompanied by a number of complications: screes, landslides, oil and gas shows. The cavernousness values in the considered interval reached 2.0-2.2 units. Moreover, water shows and intense losses of the drilling fluid were noted. An analysis of the results of field tests of the proposed technology showed that the strength and stability of the borehole walls increased significantly (cavernousness ratio decreased to 1.0–1.09 units). Oil and gas shows and losses of drilling fluid were not observed, or they were extremely short-lived. In addition, the labor intensity of the drilling process has decreased due to the exclusion of technological operations to eliminate complications and change drilling fluids of various types. A decrease in the cost of drilling fluids and a reduction in the construction time of the well as a whole was noted. Conclusions. The conducted studies confirmed the correctness of the approach to solving the set scientific problems, methodically based on systemic principles. Indicators characterizing the effectiveness of methods for strengthening the walls of wells under construction have been identified. It was determined that as a result of field tests, the stability and tightness of the walls of 9 experimental wells increased. This made it possible to exclude loss of drilling fluid, gas, oil and water intrusions in the process of penetrating permeable rocks. The proposed technical and technological solutions allow us to successfully solve the set scientific and technical problems, which are recommended to be tested in the conditions of fields in other regions of Russia and abroad.

An analytical review of the design features and technological capabilities of the most common serial downhole
hydraulic motors (screw, turbine) designed for drilling wells without rotation of the drill string and in which the pressure flow of the working fluid is used as a source of energy for the rotation of the rock cutting tool is made. A design scheme of a multi-chamber rotary hydraulic machine according to the “rotating stator around a fixed rotor” scheme is proposed, which allows maximum use of the potential energy of the working fluid converted at the moment of stator rotation. Theoretical calculations were performed to determine the functional dependence of the technical and energy characteristics of a multi-chamber downhole hydraulic machine of a rotary type with a stator diameter of 196 mm. A comparative analysis of the technical and energy characteristics of a multi-chamber rotary hydraulic machine with turbodrills of the T195K and TPS-195M types, and a screw downhole motor DRU-1-195S was performed.