Gornye nauki i tekhnologii = Mining Science and Technology (Russia)

Advanced search
Vol 6, No 2 (2021)
View or download the full issue PDF (Russian) | PDF


65-72 469

Rock texture and structure play an important role in the formation of the rock physical properties, and also carry information about their genesis. The paper deals with the simulation of geometric shapes of various structures and textures of rocks by the finite-element method (FEM). It is carried out by programmed detailing of the element properties and their spatial location in the simulated object. When programming structures, it is also possible to set the physical properties of various parts of the model, grids, initial and boundary conditions, which can be changed in accordance with the scenarios for numerical experiments. In this study, on the basis of FEM, simulation of various structures and textures of rocks with inclusions and disruptions was implemented in COMSOL Multiphysics in conjunction with Matlab. Such structures are used to conduct computer generated simulations to determine physical properties of geomaterials and study the effect on them of agents of various physical nature. The building of several models was considered: a rock specimen with inclusions in the form of ellipses of equal dimensions with different orientations; a sandstone specimen containing inclusions with high modulus of elasticity in cement matrix when deforming; a limestone specimen with fractures filled with oil and saline water when determining its specific electrical resistance. As an example of a fractured structure analysis, the influence of the filler on the electrical resistance of the limestone specimen containing a system of thin elliptical predominantly horizontal fractures was considered. The change in the lines of current flow at different ratios between the matrix and the fracture filler conductivities and their effect on the effective (averaged) conductivity of the rock specimen was clearly demonstrated. The lower conductivity of the fracture filler leads to increasing the length and decreasing the cross-section of the current flow lines that, in turn, leads to significant decrease in the conductivity of the fractured rock specimen. The higher filler conductivity results in a slight increase in the conductivity of the fractured specimen compared to that of the homogeneous isotropic specimen. The resulting structures can be used for numerical experiments to study physical properties of rocks.


73-89 372

The study hypothesis is determined by the statement that the identification of a set of issues covering all stages of introducing technogenic deposits into economic turnover will allow focusing on solving a set of complex problems associated with technogenic mineral accumulations (mining waste). The aim of the study was to identify problems requiring priority resolution, which, in turn, accelerated the transition to a circular economy (implementation of the concept of closed supply chains) in the context of handling technogenic mineral accumulations. In the course of the study, issues of legal nature were identified (caused by the absence of the legal status of technogenic deposits and the regulation of their use regime in the Federal Law of the Russian Federation “On Subsoil”). A number of aspects are due to the complexity and cost of development of technogenic deposits, which are rightfully classified as unconventional types of raw materials, and in most cases require state support (for involving in commercial exploitation) in the form of a system of economic incentives, the feasibility of which should be confirmed by newly-elaborated regulatory legal acts. State should use the tools of public-private partnership in solving waste problems, in particular, referring to the positively proven experience of implementing regional target programs for processing of technogenic mineral accumulations. Viability of transition to circular economy in the sphere of handling technogenic mineral accumulations depends on the timeliness of the identified problems solution.

90-104 405

The study relevance is due to the low efficiency of logistics systems of industrial enterprises and a limited set of methods for managing operational logistics activities. The work touches upon the key aspects of the activities of company logistics departments, namely the management, motivational, operational, process and information functions. The models and tools presented in the study allow implementing a large-scale concept of changes that modifies the work methods, economics and status of logistics of a large industrial holding company. The developed concept is based on methods of finding a balance between logistics costs, services and risks of dependence on third-party logistics operators, as well as on a set of tools to reduce the share of logistics costs in the cost of finished products of industrial holding companies. A portfolio of projects aimed at introducing a matrix organizational and managerial structure of a logistics company, regulating core activities, normalization and planning of operating activities, introducing a KPI system and staff motivation is used in the study as the basic transformation tools. The issues of automation of a logistics company main processes and creation of a 4PL-operator on the basis of an existing logistics company of a large industrial holding company allowing achieving a significant economic effect and reducing the share of logistics costs in the cost of finished products are considered.


105-113 272

Underground oil and gas reservoirs (formations) are characterized by spatial variability of their structure, material composition and petrophysical properties of its constituent rocks: particle size distribution, porosity, permeability, structure and texture of the pore space, carbonate content, electrical resistivity, oil and water saturation and other properties. When assessing development and exploitation conditions for underground gas storages, created in depleted underground oil and gas reservoirs, the inherited nature of the reservoir development should be taken into account. Therefore, identifying the features of variations in well productivity is a crucial task, solution of which can contribute to the creation of more efficient system for underground gas storage exploitation. The paper presents the findings of comparative analysis of spatial variations in well productivity during the exploitation of the Garadagh underground gas storage (Azerbaijan), created in the depleted gas condensate reservoir. An uneven nature of the variations in well productivity was established, which was connected with the reservoir heterogeneity (variations in the reservoir lithological composition and poroperm properties). The research was based on the analysis of spatial variations of a number of reservoir parameters: the reservoir net thickness, lithological composition and poroperm properties. The analysis of variations in the net thickness and poroperm properties of the VII horizon of the Garadagh gas condensate field was carried out based on the data of geophysical logging of about 40 wells and studying more than 90 core samples. The data on of more than 90 wells formed the basis for the spacial productivity variation analysis. The analysis of productivity variation in the space of well technological characteristics (based on data from 18 wells) in the Garadagh underground gas storage (UGS) was carried out through the example of the volume of cyclic gas injection and withdrawal in 2020–2021 season. The studies allowed revealing non-uniform spacial variations in the volumes of injected and withdrawn gas at the Garadagh UGS, created in the corresponding depleted gas condensate reservoir. The features of the UGS exploitation conditions are in good agreement with the features of the reservoir development conditions (variations in the well productivity). The inherited nature of the reservoir development and the underground gas storage exploitation is substantiated by the reservoir heterogeneity caused by the spatial variability of the reservoir lithological composition and poroperm properties. Assessing and taking into account the reservoir heterogeneity when designing underground gas storage exploitation conditions should be an important prerequisite for increasing UGS exploitation efficiency.


114-120 317

At present time,Mozambiqueis called the “Rising Star of South Africa” mainly due to the rapid development of its mining industry. Mineral resources sector ofMozambiqueis one of the most dynamically developing sectors of the country’s economy.China,BrazilandIndiahave recently become the main partners forMozambique. Recently, a number of projects is being implemented in the country, for example, Auroch Minerals Manica Gold in gold production. Increasing coal production is connected with commissioning of the Moatize open pit, which is being developed by Brazilian Vale Company, as well as Benga mining company owned by Indian ICVL consortium. The analysis of the extraction of certain mineral types inMozambiquepresented in the paper demonstrates general picture of mining industry development in the country. The analysis findings allow identifying the causes of negative phenomena in the industry, manifesting themselves in decreasing production of certain types of minerals. For instance, the main reasons for the decline in coal production were dropping labor productivity, deterioration of mining conditions, and depletion of the most accessible coal reserves, extractable by open pit mining. In this regard, development of underground mining methods providing for opening of deep deposits by vertical shaft sets is highly relevant. The experience of the neighboringRepublicofSouth Africashows that, in the mining and geological conditions of the south of the African continent, highspeed shaft sinking methods accelerating deposit development can be successfully applied.


121-127 443

Alumina production is rather complex technological process of processing mineral raw materials that requires development of effective technological solutions, including in terms of efficiency of using electric energy. The paper is devoted to studying the power supply system of an alumina refinery inLam Dong Province,Vietnam. The tasks that need to be solved for improving the power quality in the power supply system were analyzed. It was shown that non-linear loads significantly degrade the power quality that in turn leads to equipment damage, malfunction and decreasing the refinery productivity. Models of the refinery power supply system were developed and, using which, the quality of power was assessed at the 6 kV voltage utility bus of the power supply system, as well as at the 6 kV and 0.4 kV buses of distribution substations of individual refinery’s subdivisions. Analysis of the simulation findings showed that the nonlinear loads lead to significant distortions of sinusoidal forms of voltages and currents, and decreasing the power factor. Based on the simulation results, it was concluded that voltage harmonics and current harmonics at nonlinear load at the low voltage buses of 0.4 kV and at the buses of 6 kV exceed the permissible limits of the harmonics in accordance with IEEEST519-1992 international standard. Proposals were developed for improving the power quality in the refinery power supply system. For suppressing higher harmonics of current and voltage, it was recommended to use special power quality regulators in the alumina refinery power supply system. It was proposed to use active harmonic filters as the power quality regulators. The proposed solutions allowed obtaining practically sinusoidal forms of voltages and currents in the alumina refinery power supply system.


128-135 252

In the process of operation of present-day mechanical equipment, dynamic loads arise, leading to the failure of parts, assemblies and mechanisms and, thus, reducing the equipment life time and operational reliability. A method has been developed for calculating the design and technological values of a pin flexible coupling with a flexible disk-type element, using the method of central compositional rotatable uniform planning of the second order and the finite-element method for calculating stresses using a computer-aided design system. The analytical dependence of the torque on the PCD (pin (centers of holes for pin) circle diameter) and the width of the flexible element with certain physical and mechanical properties was substantiated, on the basis of which the formula for the total width of the flexible disk-type element was obtained, taking into account the value of the required torque and the given PCD. In order to check the obtained dependence of the nominal torque, an additional study of couplings with the given PCD was carried out at different total width of the flexible element. The implemented research allowed determining the influence of the design characteristic values on the transmitted torque of a pin flexible coupling with a flexible disk-type element. A standard-size range of couplings with certain design and technological values has been proposed.

136-143 365

Mine transport is an integral part of mining process. The performed analysis of modern monorail autonomous locomotives indicates that this type of underground auxiliary transport is the most promising today due to a number of advantages that were identified in this study. To assess performance indicators of mine monorail locomotives, a number of characteristics are currently used, for instance, the dependences between several parameters of propulsion system operation. The type of characteristic is determined by an independent variable to be selected from the list of the operational or design parameters. To substantiate performance indicators of autonomous mine suspended monorail locomotives, the authors proposed the relationship between the characteristics of the traction energy chain equipment and the diesel locomotive propulsion system efficiency factor. To assess the efficiency of mine suspended monorail locomotive operation, a composite indicator for assessing efficiency of various types of traction was proposed: the operational efficiency factor. This indicator takes into account varying the efficiency factor of the energy chain units depending on their operating modes. When determining the functional dependencies of varying the efficiency factor of power and auxiliary units of monorail locomotives, a grouping of the main parameters according to the features depending on the economic characteristics of the propulsion system and its operating modes was proposed. The operational efficiency factor of the locomotive as a whole is determined both by the economic characteristics of all units of its energy chain and by the modes of their operation.


144-153 338

Mineral resource base development objectively requires high-quality human resources for mining and geological sector. A brief analysis of the geological sector development tendencies and ongoing projects demonstrates the scale of technological challenges facing the sector. Over the past decades, Russia has been facing serious problems that can become constraining factors in economic development, regional development, and the implementation of national projects. Training of specialists for the sector is one of the challenges. In order to solve such a complex problem, Federal State Educational Standards for training of specialists in the specialties “Applied Geology”, “Geological Exploration Technique” were developed. The Educational Standards provide for the formation of future geologists’ professional competencies relevant to the industry. Comparison of the competence models of the Standards with the main priority lines of the development of science and technologies in framework of the implementation of the state scientific and technological policy of Russia shows that they allow universities to form programs for geologist training that respond to modern challenges. Internship (field training) programs play a special role in ensuring the quality of training for geologists. They play a decisive role in the formation of universal and professional competencies and open the world of a subculture of professionals in this field to the future specialists that is very important for a young person who devotes his future to geology. The paper highlights a significant role of the government, the academic and professional community – universities, companies, research and public organizations – in the formation of human resources for the mining and geological sector. An urgent need was identified for the creation of a domestic system of professional qualifications (mining engineer, mining engineer-geologist, mining engineer-hydrogeologist, mining engineer for drilling wells, mining engineer-geochemist, mining engineer-geophysicist, etc.), which should ensure harmonization of the requirements for the level of specialist competence for the industry.

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

ISSN 2500-0632 (Online)