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Date submitted2024-05-08
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Date accepted2024-11-07
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Date published2025-04-25
The effect of mechanical and thermal treatment on the characteristics of saponite-containing material
Solving the problems of modern building materials science is reduced to obtaining high-quality materials, expanding and searching for a rational raw material base, which can be carried out through the use of various industrial wastes. In this paper, the possibility of using waste from the mining industry – saponite-containing material (SCM) obtained during the enrichment of kimberlite ores from the Lomonosov diamond deposit, as an active mineral additive for cement binders and concretes is considered. The influence of mechanical and thermal treatment on a number of properties of the material selected from the tailings dump and in its initial state was studied. The study of the surface activity of SCM samples consisted in determining the sorption capacity, acid-base centers and their distribution. An increase in the activity of the surface of the material particles as a result of mechanical activation and its decrease during temperature treatment were determined. These effects are associated with phase rearrangements and structural changes in the sandy-clay rock, which was confirmed during thermal analysis. The temperature effect has no pronounced effect on the microstructure, the “smoothness” of the particles and the formation of a consolidated surface of the structural elements of the saponite-containing material are noted.
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Date submitted2024-07-04
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Date accepted2024-07-04
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Date published2024-07-04
Environmental safety and sustainable development: new approaches to wastewater treatment
In 2015, the UN member states adopted the 2030 Agenda for Sustainable Development. Despite significant progress, billions of people – one in three people – do not have access to safe, clean drinking water. Modern wastewater treatment methods include a wide range of biological, chemical and physical processes, each having its own advantages and applications. This thematic volume considers the latest achievements in wastewater treatment technologies, wastewater purification and treatment as well as their potential applications at the local level. The problem of surface water pollution is relevant for all regions of the world. One of the largest sources of pollutants is mining and processing industry. The first stage in the development of wastewater treatment technologies is monitoring of anthropogenically modified water bodies.
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Date submitted2024-01-18
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Date accepted2024-05-02
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Date published2024-12-25
Industrial clusters as an organizational model for the development of Russia petrochemical industry
The article explores the challenges facing Russia petrochemical industry over the past decade and examines the reasons behind its significant lag compared to other industrialized nations. It presents a review of academic research on clusters accompanied by a comparative analysis, generalization, and consolidation of factors influencing the development of the petrochemical industry in Russia. It is argued that advancing the petrochemical industry from production plants to integrated production complexes necessitates a shift towards clustering, which will improve resource utilization efficiency, bolster product competitiveness, and reduce production costs. The article examines and consolidates key cluster concepts, encompassing definitions, characteristics, composition, and constituent elements. It also examines strategic documents guiding the development of the petrochemical sector, assesses the progress made in forming petrochemical clusters in Russia, and draws upon European and Asian experiences and government support tools in the domain of petrochemical clusters. The successful development of petrochemical clusters in Russia is argued to be strongly dependent on state initiatives and support for infrastructure development. Additionally, the presence of research organizations within clusters is crucial for fostering high-tech product innovation and forming an efficient value chain that integrates research and development with specific assets. When establishing petrochemical clusters in Russia, it is essential to consider the unique characteristics of each cluster, including the types of raw materials and resources used, the necessary infrastructure, and the specific support measures and incentives provided by the state.
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Date submitted2023-04-10
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Date accepted2024-12-27
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Date published2024-04-25
Optimization of specific energy consumption for rock crushing by explosion at deposits with complex geological structure
The selection of efficient drilling and blasting technology to achieve the required particle size distribution of blasted rock mass and reduce ore dilution is directly related to the accurate definition of rock mass properties. The zoning of the rock massif by its hardness, drillability and blastability does not consider the variability of the geological structure of the block for blasting, resulting in an overestimated specific consumption of explosives. The decision of this task is particularly urgent for enterprises developing deposits with a high degree of variability of geological structure, for example, at alluvial deposits. Explosives overconsumption causes non-optimal granulometric composition of the blasted rock mass for the given conditions and mining technology. It is required to define physical and mechanical properties of rocks at deposits with complex geological structure at each block prepared for blasting. The correlation between the physical and mechanical properties of these rocks and drilling parameters should be used for calculation. The relation determined by the developed method was verified in industrial conditions, and the granulometric composition of the blasted rock mass was measured by an indirect method based on excavator productivity. The results demonstrated an increase in excavation productivity, thus indicating the accuracy of given approach to the task of identifying the rocks of the blasted block.
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Date submitted2023-04-13
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Date accepted2023-10-25
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Date published2025-02-25
Assessment of the ecological state of aquatic ecosystems by studying lake bottom sediments
- Authors:
- Mariya A. Chukaeva
- Tatyana V. Sapelko
The article presents the results of coupled palynological and geochemical studies of five various genesis lakes, located along the route of the expedition “In the footsteps of Alexander von Humboldt in Siberia, Altai and Eastern Kazakhstan”, dedicated to the double anniversary: the 190th anniversary of the expedition across Russia of the famous scientist and his 250th birthday. A geochemical analysis of water and bottom sediments of Ik Lake (Siberia), Lakes Kolyvanskoe and Beloe (Altai), Lake Bezymyannoe (Kazakhstan) and Nagornyi Pond (Altai) was carried out. Based on their results an assessment of studied lakes ecological state was given through single and integral criteria. A high level of pollution was noted for Nagornyi Pond and Lake Bezymyannoe, which is caused by a significant technogenic load from nearby mines. This is consistent with the data of palynological research. The aquatic ecosystems of Lakes Kolyvanskoe and Beloe are characterized by a satisfactory ecological situation, but they experience an increased recreational load. The results of spore-pollen analysis and analysis of non-pollen palynomorphs showed the low ability of these lakes to self-healing. The most favorable ecological state and high self-cleaning capacity were noted for Lake Ik, which is consistent with the data of palynological studies. It is being confirmed with the results of palynological studies. It was therefore concluded about the ability to make a quick assessment of the aquatic ecosystems’ ecological state by studying lakes using coupled palynological and geochemical analysis.
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Date submitted2023-07-20
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Date accepted2023-10-25
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Date published2024-04-25
Directions in the technological development of aluminium pots
- Authors:
- Еvgenii S. Gorlanov
- Leopold I. Leontev
Directions for the technical and technological development of aluminium industry, existing and promising projects to reduce the energy consumption and the environmental impact are analyzed. The active participation of the state in the organization of financial instruments for the ecological reconstruction of obsolete production facilities is discussed. In spite of the fact that the technology of aluminium pots is developed towards the increase of a single capacity, but with limited potential of reducing energy consumption and greenhouse gases emission, the possibilities for the increase of specific output are practically non-existent. Therefore, such projects like pots, equipped with inert anodes and drained cathodes arise and are under development, the successful completion of which is unlikely after multi-year researches and pilot tests. To continue the works related to inert anodes the decisive answer about the industrial safety of local sources of the massive oxygen emissions to atmosphere is required from competent entities. The drained cathode project, after discussing the existing problems, seems unfeasible. As opposed to the existing technology the development of the pots with vertical electrodes offers great opportunities to the designs of inert anodes and drained cathodes. Positive results of using shaped electrodes, homogenizing their surface and developing the methods for the synthesis of composite cathodes directly during the electrolytic process were obtained in laboratory conditions. It is expected that the combination of these trends and the successive dimensional scaling shall allow using the vertical electrodes at the next level for the fold increase of specific pot capacity and for the decrease of energy consumption and greenhouse gas emissions.
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Date submitted2022-05-17
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Date accepted2023-04-03
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Date published2024-02-29
Improvement of concentrate quality in flotation of low-rank coal
- Authors:
- Sergei A. Kondratev
- Tatyana A. Khamzina
Percentage of high-rank coal with low content of ash, moisture, and sulfur in total coal production output is low. Most of the produced coal has a low quality (lignite, bituminous coal: long-flame and fiery). Under increasing requirements for ecological cleanness of coal, the efficient use of coal products is only possible after improvement of their processing properties. The authors discuss the enhancement of flotation efficiency of low-rank coal using the mechanism of physisorption of a collecting agent in particle – bubble attachment. It is explained why the yield of concentrate with low ash content increases as a result of combination of collectors having different physical properties. It is shown that the surface activity of a heteropolar agent relative to the gas – liquid interface and the adsorption density of the agent govern its collecting properties. Based on the recovery – surface activity relationship, the correlation is found between the collecting activity of a chemical compound and the structure of its molecules. The combination of the collectors with different surface activity enables adjusting collectability and selectivity of the blend. The physisorption mechanism of collectors can be a framework for developing recommendations on modification of concentrate yield and ash content, and on selection of optimized ratios of surface activities of miscible collectors relative to the gas – liquid interface.
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Date submitted2023-01-12
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Date accepted2023-06-20
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Date published2023-07-19
Improvement of energy efficiency of ore-thermal furnaces in smelting of alumosilicic raw materials
The issues of energy saving in pyrometallurgical production during processing of mineral raw materials in ore-thermal furnaces are particularly important for the development of new energy-efficient technologies. The reduction of the specific power consumption during melting at different stages of heating and melting of charge materials when modeling is related to obtaining kinetic curves in the process of kyanite concentrate regeneration in polythermal conditions. Based on practical data of carbo-thermal reduction the mathematical modeling of reduction processes from alumosilicic raw materials – kyanite was carried out. In this work, the nonisothermal method based on a constant rate of charge heating (i.e. a linear dependence between time and temperature) was used for the reduction of kyanite charge, which saves electrical energy. The experiments were carried out on a high-temperature unit with a heater placed in a carbon-graphite crucible. Based on the obtained kinetic dependences of nonisothermal heating of enriched kyanite concentrates in plasma heating conditions we obtained a number of kinetic anamorphoses of the linear form which point to the possibility of describing the reaction rate using the modified Kolmogorov – Erofeev equation for given heating conditions and within a narrow temperature range. The complex of mathematical modeling makes it possible to create a control algorithm of technological process of reduction of kyanite concentrate to a metallized state within the specified temperature range for the full flow of reaction exchange and to reduce the specific power consumption by 15-20 %. With the help of the received kinetic dependences, taking into account the thermodynamics of processes and current state of the art it is possible to create a universal thermal unit for the optimal carbothermal reduction of charge to a metallized state (alloy) with minimum power inputs compared to existing technologies.
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Date submitted2022-09-30
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Date accepted2023-02-13
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Date published2023-04-25
Hydrogeoecological conditions of technogenic groundwater in waste disposal sites
The specific hydrogeoecological conditions of aquifers of some technogenic formations, mainly iron ore skarn-magnetite and titanium-magnetite formations, are considered. The resulting wastes, which are stored in waste disposal sites during development of deposits, due to the impact of a number of factors (natural and technogenic) form technogenic waters. Waste disposal facilities are complex engineering structures (dumps and sludge storages), which in turn create their own hydrogeoecological conditions, which must be investigated in order to prevent and minimize environmental and economic damage caused by these objects to the aquatic environment. The paper presents long-term field and laboratory studies of the aquatic environment under the influence of a waste disposal facility in the Middle Urals – one of the largest tailings, representing a potential environmental and man-made hazard. This tailing dump contains tens of tons of waste – enrichment tailings and creates specific hydrogeoecological conditions on the territory. Based on many years of monitoring studies, an analysis of these conditions was carried out – the quality of groundwater affected by the tailings was assessed. It is shown that groundwater is of technogenic nature, i.e. are man-made waters that have a significant impact on the surface and underground hydrospheres of the territory.
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Date submitted2022-07-15
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Date accepted2022-12-13
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Date published2023-02-27
Assessment of the efficiency of occupational safety culture management in fuel and energy companies
The results of development, testing and implementation of the process of occupational safety culture management in a fuel and energy company including the assessment of current state, assessment of deviation, formation of control action and its implementation are presented. Using the methods of mathematical analysis, the components of occupational safety culture and criteria for their evaluation were developed. As a control action, a procedure for conducting behavioural safety audit was elaborated and implemented. Proceeding from the results of analysing average ratings of safety culture components among the employees prior to and after the introduction of behavioural safety audit, it was concluded that there was a statistically significant increase in the average values of 12 out of 16 ratings of safety culture components. Analysis of the results of 1,011 audits showed the absence of an “alarm area” at the enterprise. Introduction of the developed process management model promotes an increase in the efficiency of attaining a high level of occupational safety culture in fuel and energy companies.
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Date submitted2022-03-22
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Date accepted2022-11-17
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Date published2023-02-27
Development of composition and study of sorbent properties based on saponite
The development of a comprehensive approach to preventing the pollution of natural objects is necessary due to the high requirements of environmental legislation for the discharge of industrial wastewater. Adsorbents are used in various industries to extract heavy metals from wastewater. In this study the possibility of using saponite clay as a raw material for the production of sorbent for the extraction of copper ions Cu 2+ from industrial wastewater is considered, a recipe and technology of sorbent production are developed, and its chemical composition is established. It has been established that the optimum temperature for heat treatment of the sorbent and corresponds to 550 ºC, since at this temperature saponite extrudates acquire strength (strength 34.1 kg/mm 2 ) and textural properties (specific surface area of pellets 22.803 m 2 /g), allowing them to be used as sorbents. The kinetics of molecular adsorption was studied using model solutions of copper (II) sulfate. The extraction efficiency of copper (II) ions from the model solutions is 93 %. Extraction efficiency of copper (II) ions from copper plating wastewater reaches 94 %. SEM results confirm the presence of metal on the sorbent surface.
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Date submitted2022-07-15
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Date accepted2022-12-13
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Date published2023-02-27
Mathematical modelling of displacement during the potash ores mining by longwall faces
In favourable mining conditions, in particular at the Starobinskoye potash deposit (Belarus), longwall mining systems are used. They cause a high human-induced load on the subsoil, including intense deformation of the ground surface. The presented investigations are aimed at studying the dynamics of the ground surface displacement during the longwall face advance. Mathematical modelling was carried out in an elastic-plastic formulation with numerical implementation by the finite element method. The condition for the roof rocks collapse was opening of the contact between the seams when its boundaries were reached by shear fractures or formation of the tensile stresses area at the outcrop. With the working front advance, an increase in subsidence is observed, followed by its stabilization to a value determined by the process parameters of mining operations and the physical and mechanical properties of collapsed rocks. In this case, each point of the ground surface experiences sign-alternating horizontal deformations: when the front approaches, it causes tension, and when it moves away, compression. The obtained results of mathematical modelling are in good agreement with the data of instrumental measurements of the ground surface displacements, which indicates the adequate description of the rock mass deformation during the slice excavation of sylvinite seams by longwall faces.
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Date submitted2022-05-26
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Date accepted2022-11-17
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Date published2022-12-29
Renovation method of restoring well productivity using wavefields
A stagewise theoretical substantiation of the renovation vibrowave method of influencing the near-wellbore zone of reservoir for restoring well productivity is presented. The area of treatment by the proposed method covers the reservoir with a heterogeneous permeability with fractures formed by fracking. In this method a decrease in concentration of colmatants occurs due to a change in direction of contaminants migration. Under the influence of pressure pulses, they move deep into the reservoir and disperse through the proppant pack. The results of mathematical modelling of the propagation of pressure wave and velocity wave and the calculations of particles entrainment in wave motion are presented.
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Date submitted2022-03-14
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Date accepted2022-06-20
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Date published2022-11-10
Model of a walking sampler for research of the bottom surface in the subglacial lake Vostok
Technologies and technical means for investigation of subglacial lakes in Antarctic is a new developing scientific and technical direction, which today has no clearly established methodology. Based on the developed technology of drilling a new access well to lake Vostok and its penetration as well as analysis of existing methods and devices for bottom sediment sampling, a basic model of a sampler with a walking-type mover, capable of moving along different trajectories and operating in a wide technological range, is proposed. The proposed device model is equipped with different actuators for sampling the bottom surface with different physical and mechanical properties. Based on the presented basic model of the walking sampler, a mathematical model of the device was developed, which was based on the theoretical mechanics methods. As a result of conducted research the dependencies were obtained, which allow making a scientifically justified choice of optimal values for geometric and force parameters of the walking sampler. A conceptual design of the walking sampler has been developed, taking into account the mutual location and coupling of its main components, the overall dimensions of the delivery tool, as well as the esthetic component of the device.
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Date submitted2022-03-17
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Date accepted2022-10-04
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Date published2022-11-10
Improving the reliability of 3D modelling of a landslide slope based on engineering geophysics data
Landslides are among the most dangerous geological processes, posing a threat to all engineering structures. In order to assess the stability of slopes, complex engineering surveys are used, the results of which are necessary to perform computations of the stability of soil masses and assess the risks of landslide development. The results of integ-rated geological and geophysical studies of a typical landslide slope in the North-Western Caucasus spurs, composed of clayey soils, are presented. The purpose of the work is to increase the reliability of assessing the stability of a landslide mass by constructing a 3D model of the slope, including its main structural elements, identified using modern methods of engineering geophysics. Accounting for geophysical data in the formation of the computed 3D model of the slope made it possible to identify important structural elements of the landslide, which significantly affected the correct computation of its stability.
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Date submitted2022-04-29
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Date accepted2022-07-21
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Date published2022-11-10
Deep structure, tectonics and geodynamics of the Sea of Okhotsk region and structures of its folded frame
The use of the zonal-block model of the earth's crust for the construction of regional tectonic schemes and sections of the earth's crust based on a complex of geological and geophysical data makes it possible to consider the resulting maps and sections as tectonic models. The main elements of such models are blocks with an ancient continental base and interblock zones formed by complexes of island arcs, an accretionary prism, or oceanic crust. The developed geotectonic model of the Sea of Okhotsk region reflects the features of the deep structure, tectonics, and geodynamics. The Cimmerian Novosibirsk-Chukotka, Verkhoyansk-Kolyma, Kolyma-Omolon, and Amur folded regions and the Alpides of the Koryak-Kamchatka and Sakhalin-Sikhote-Alin folded regions are developed along the northern, western, and southern boundaries of the Sea of Okhotsk megablock with a continental crust type. From the east, the megablock is limited by oceanic basins and island arcs.
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Date submitted2022-02-24
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Date accepted2022-05-25
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Date published2022-07-26
Litsa uranium ore occurrence (Arctic zone of the Fennoscandian Shield): new results of petrophysical and geochemical studies
Mineralogical, petrophysical and geochemical studies have been carried out to determine the sequence and formation conditions of uranium mineralization within the Litsa ore occurrence (Kola Region). Mineralogical studies show the following formation sequence of ore minerals: uraninite – sulfides – uranophane, coffinite, pitchblende. Two stages of uranium mineralization are distinguished: Th-U (1.85-1.75 Ga) and U (400-300 Ma). The distribution of physical properties of rocks in the area is consistent with the presence of two temporal stages in the formation of mineralization with different distribution and form of uranium occurrence in rocks. The factors that reduce rock anisotropy are the processes of migmatization and hydrothermal ore mineralization, which heal pores and cracks. Fluid inclusions in quartz studied by microthermometry and Raman spectroscopy contain gas, gas-liquid and aqueous inclusions of different salinity (1.7-18.4 wt.% NaCl-eq.). According to homogenization temperatures of inclusions in liquid phase, the temperature of the Paleoproterozoic and Paleozoic stages of uranium mineralization at the Litsa ore occurrence is ~ 300 and 200 °С, respectively. Correlations of the spatial distribution of elastic anisotropy index with an elevated radioactive background allow using this petrophysical feature as one of the prognostic criteria for uranium and complex uranium mineralization when carrying out uranium predictive work.
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Date submitted2021-03-18
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Date accepted2021-11-30
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Date published2021-12-27
Deformations assessment during subway escalator tunnels construction by the method of artificial freezing of soil for the stage of ice wall formation
- Authors:
- Evgenii M. Volokhov
- Diana Z. Mukminova
The work is devoted to the study of the processes of displacement and deformation of the surface during the escalator tunnels construction of the subway by the method of artificial freezing of soils. The features of the construction and freezing technology, the rocks characteristics in which the escalator tunnels made are considered. The data of specially organized, full-scale surveying observations of deformations on the earth surface are presented. The main factors influencing deformation processes in the frozen strata of a layered inhomogeneous rock mass with inclined tunneling are determined, the complexity of the predictive task and the need to simplify the design scheme are shown. The work is focused on the assessment of the least studied geomechanical processes of soil heaving-uplifts and deformations during the periods of active and passive freezing stages. When studying the displacements processes of the earth surface and rock mass, the finite element method and analysis of the obtained data using field observations of displacements were used. A simplified calculation scheme is proposed for modeling, which allows taking into account the uneven influence of frozen rocks of an inhomogeneous layered rock mass with a large inclined tunneling. The satisfactory convergence of the data of field surveying observations on the earth surface and the results of modeling geomechanical processes for the period of active and passive freezing stages is shown. The proposed calculation scheme is recommended for the prediction of deformation at the stages of underground construction, characterized by the development of the most dangerous tensile deformations of buildings and structures on the surface.
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Date submitted2021-04-23
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Date accepted2021-09-07
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Date published2021-12-16
Development of the concept of an innovative laboratory installation for the study of dust-forming surfaces
Currently, the determination of the emission rate of suspended solids from a unit of the surface area of a man-made mass at various parameters of the wind flow is not sufficiently described. The analysis of the world experience of researchers shows that existing laboratory installations have various design features that do not allow to correctly determine the mass of the dust being flapped and wind-blown. Based on the analysis results, the concept of an innovative laboratory installation for the study of dust-forming surfaces has been developed. It takes into account the influence of wind shadows, the deturbulization of an artificially created air flow, the possibility of regulating not only the flow velocity mode, but also the creation of a vacuum or disturbance in the area of sample placement, as well as the formation of a certain angle of wind flow attack relative to the surface. The concept provides for the possibility of determining the volume of dust emissions by the values of the lost dust masses in the sample and by the values of dust concentrations in the outgoing stream. The calculation of the main basic elements of the installation using the ANSYS FLUENT software package was carried out. The model and configuration of the wind tunnel have been developed and calculated, the main geometric parameters and functional elements for the possibility of use in scientific work have been determined. For practical use of the empirical roughness value of the underlying surface, its values are recommended in a wide range – from zero for the water surface to 0.44 for large cities with tall buildings and skyscrapers.
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Date submitted2020-06-16
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Date accepted2021-03-29
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Date published2021-09-20
Empirical regularities investigation of rock mass discharge by explosion on the free surface of a pit bench
- Authors:
- Igor A. Alenichev
- Ruslan A. Rakhmanov
Minimizing the discharge of blasted rock mass into the developed space of the pit is a very relevant area for study, as it allows to increase the processability of work and reduce the cost of mining. The article presents the results of experimental industrial explosions, during which the study of this issue was conducted. The main purpose of the work was to establish the key factors affecting the volume of rock mass discharge to the pit haulage berm. During the analysis of the world experience of research on this topic, the key factors affecting the formation of collapse and discharge – natural and technological – are identified. The method of conducting experiments and collecting data for analyzing the influence of technological parameters of location, charging and initiation of wells on the volume of rock mass discharge is described. It is established that the main discharge to the pit haulage berm is formed by the volume of rock mass limited by the prism of the slope angle. With a sufficient rock mass displacement from the edge of the bench crest towards the center of the block, only the wells of the 1st and 2nd rows participate in the discharge formation. Empirical dependences of the total volume of rock mass discharge on the length of the block along the bench crest, the specific consumption of explosives, the size of a rock piece P 50 and the rate of rock breaking are obtained. The obtained results can be used to design the parameters of the drilling and blasting operations (DBO), as well as to predict and evaluate the possible consequences of a mass explosion in similar mining and geological conditions.
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Date submitted2020-06-16
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Date accepted2020-07-13
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Date published2020-11-24
Study of Aluminum Influence on the Adhesion of Stainless Steel in Flame Spraying
This paper is dedicated to a study of aluminum influence on the improvement of surface adhesion strength. The main purpose of this work is to investigate the strength of adhesion to the substrate by mixing flame spray powder with aluminum, which not only possesses high corrosion resistance and conductivity, but also provides additional strength, as it combines and reacts with other components of the powder. Research results of sandblasting dependence on surface roughness parameter Ra are demonstrated. The paper describes authors’ original device for a measuring instrument “Profilometer”, which was also used for measuring roughness parameter in order to obtain comparative results. Authors present results of adhesion measurements given obtained values of surface roughness by mixing nominal chemical composition of PR-30X13 powder, used as a testing material, with aluminum, which reacts with oxides on the surface of steel substrates, imparts strength to the bonding between the coating and the substrate, protects the base metal due to a combination of chemical components of the powder and creates a layer of dense surface coating. These dependencies are analyzed and parameters, exerting the greatest influence on their values, are identified. Taking into account the results obtained through numerical modeling, authors propose a mathematical model of a dependency between adhesion strength and certain values of surface roughness for different chemical compositions of flame spray powder. These studies will help in the development of certain material types for spraying and hardening of steel parts and products in order to improve their durability.
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Date submitted2019-10-17
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Date accepted2020-01-24
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Date published2020-04-24
Composition and probable ore igneous rocks source of columbite from alluvial deposits of Mayoko district (Republic of the Congo)
The article presents the results of optical, electron microscopic and electron microprobe studies of columbite group minerals, collected during heavy mineral concentrate sampling of alluvial deposits in the Mayoko region (Republic of the Congo). The aim of the study is revealing tantalum niobates ore body in this region. We found that these minerals in loose deposits are represented by two grain-size groups: less than 1.6 mm (fine fraction) and 1.6-15 mm (coarse fraction). The grains of both fractions belong mainly to columbite-(Fe), less often to columbite-(Mn), tantalite-(Mn) and tantalite-(Fe), contain impurities of Sc, Ti, and W. The crystals have micro-scaled zoning (zones varies slightly in the Ta/Nb ratio values) and contains a lot of mineral inclusions and veins represented by zircon, pyrochlore supergroup minerals and others. Columbite-(Fe) and columbite-(Mn) are characterized by an increased content of Ta 2 O 5 up to the transition to tantalite-(Fe) and tantalite-(Mn). This allows us to exclude the formation of subalkaline rare-metal granites, their metasomatites (albitites and greisenes) and carbonatites, from the list of possible columbite ore rocks source in the Mayoko district. Thus, beryl type and complex spodumene subtype rare-element pegmatites of the mixed petrogenetic family LCT-NYF (according to P.Černý) should be considered as a probable root source. The results of the research should be taken into account when developing the methodology for prospecting in this area.
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Date submitted2019-05-30
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Date accepted2019-09-04
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Date published2020-02-25
Prospects for industrial methane production in the mine n.a. V.M.Bazhanov using vertical surface wells
The estimated methane resources in the coal stratum of Donbass are 798.5 billion m 3 , including 119.5 billion m 3 in the Donetsk-Makeevsky area. Such significant potential implies that methane can be used not only for industrial production and energy purposes but also as a commodity for the chemical industry. However, in practice, commercial production of methane from coal seams, as is done in the fields of the USA, Canada, India, and China, is not carried out, and methane, obtained as a by-product, is utilized for ensuring the safety of the main technological processes for coal mining. The main reasons for this are the difficult mining and geological conditions of bedding, low thickness and permeability, which does not allow to separate methane production into an independent type of activity due to its low profitability, especially with the use of new technologies based on hydraulic fracturing of coal seams. The assessment of the possibility of industrial methane production in the mine n.a. V.M.Bazhanov in the Donetsk-Makeevsky area of Donbass, which reserves equal to 23.7 billion m 3 , showed that a significant part of the methane reserves is concentrated in coal seams and interlayers with a gas content of 18.5-20.7 m 3 /m 3 . Moreover, in the host rocks, methane is practically in a liberated state. This circumstance makes possible the commercial production of methane for its utilization from the unloaded rock mass by wells drilled from the surface, without the use of hydraulic fracturing technology. The paper discusses the technology of methane extraction by a degassing well drilled from the surface into a coal-bearing stratum unloaded from rock pressure in a mining field of the 4th eastern face of the m 3 seam of the mine n.a. V.M.Bazhanov and its subsequent use as the fuel of an electric generator. It is shown that over the entire period of operation of the pilot well, the volume of actually produced methane exceeded the design value by 23 %, and the cost of the gas produced amounted to 1535 rubles per 1000 m 3 , which is more than 3 times lower than the market price for natural gas for consumers in the Russian Federation. This made it possible to make a conclusion about the possibility of industrial extraction of mine methane using vertical surface wells for its subsequent utilization in power plants, which does not imply the usage of hydraulic fracturing technology.
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Date submitted2019-05-24
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Date accepted2019-07-15
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Date published2019-10-23
Effective Power and Speed of Mining Dump Trucks in Fuel Economy Mode
- Authors:
- V. I. Alexandrov
- M. A. Vasileva
- V. Y. Koptev
Existing methods for determining the effective power, based on the calculation of the average indicator operation of the engine during the piston stroke, do not take into account the change in thermodynamic parameters and the polytropic operation of the engine, the value of which depends on the polytropic efficiency of the duty cycle. This is the reason that the calculation of the effective power leads to some error – the margin of the engine features. The identification of this stock allows us to review the entire line of dump trucks in the direction of increasing their pass- port effective capacity, which will lead to a reduction in capital purchase costs due to the choice of a previously un- derestimated and cheaper option, as well as a reduction in current operating costs due to a decrease in the specific fuel consumption rate. Taking into account the stochastic nature of the transport process and assessing the influence of all external and internal factors when calculating the rational mode of operation of a mining truck can further reduce specific fuel consumption by choosing the rational speed of its movement in loaded and empty directions.
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Date submitted2019-02-26
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Date accepted2019-05-22
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Date published2019-08-23
Systemic Diagnostics of the Arctic Industry Development Strategy
The article analyzes organizational and economic problems of the industry in the Arctic and discloses methods and tools for researching these problems. An attempt to use the method of system diagnostics is made, which has established itself as a basis for determining the development strategy of industry in the Arctic zone of the Russian Federation (AZRF). This method allows to explore the mechanism of natural resources development in the Arctic, such as hydrocarbons and marine biological resources; as well as the organization of logistics and transport corridors for trade of goods produced in the North and in the central regions of Russia. The role, significance and content of the strategy as an essential element of the system for managing natural wealth development in the Arctic in the context of its growing importance in development of global transport corridor are revealed. Importance of a systematic approach to the development of industry in the Arctic is substantiated, it will ensure development of all investors interested in this region; will allow the state, large corporations, small and medium-sized businesses to work together for the long term. The proposed method for system diagnostics of strategizing the development of industrial potential in the AZRF can be used in the implementation of «Development Strategy for the Arctic Region» as part of roadmap realization for the Arctic region.