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Date submitted2023-10-31
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Date accepted2024-11-07
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Date published2025-01-24
Specifics of magnetotelluric studies in Antarctica
One of the priority areas of scientific research in Antarctica is the study of its deep structure. Most of the continent is covered with a thick ice sheet, so the main geoscientific data are acquired using geophysical methods, among which magnetotelluric (MT) ones have the greatest penetration depth and insignificant environmental impact. The possibility of acquiring high-quality MT data in the conditions of the sixth continent has long been questioned. The work is aimed at studying the specifics of magnetotelluric survey in Antarctica. The following tasks were set: to summarize the world experience of studying Antarctica using MT sounding methods; to identify factors that negatively affect the high-quality data acquisition; to determine methods for minimizing the influence of these factors. The article analyses geophysical studies conducted by the magnetotelluric sounding method in the Antarctic region from 1964 to the present. The application of the method is complicated by the following: extremely low temperature affects the drop in the batteries capacity, freezing of the non-polarizing electrodes solution, and changes in the strength properties of materials. Electromagnetic noise occurs during strong winds; proximity to the magnetotelluric field source can violate the plane wave principle on which the method is based. The ice sheet covering most of Antarctica does not allow acquiring optimal values of the contact resistance of the electrode grounding; the extended coastline distorts the acquired data. Studies of the influence of factors complicating the MT sounding method in the coastal and central parts of Antarctica made it possible to formulate recommendations for preparing equipment and adapting the work procedure, modifying the processing flow and a set of measures to ensure safety, the implementation of which will both allow safe performance of geophysical investigations and high-quality data acquisition.
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Date submitted2023-11-10
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Date accepted2024-05-02
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Date published2024-08-26
Paleoproterozoic Saltakh Pluton, Anabar Shield: mineralogical composition, age and a geodynamic setting
- Authors:
- Nikolai I. Gusev
- Lyudmila Yu. Romanova
The Saltakh Massif is located in the northern Anabar Shield, in the Saltakh shear-zone. It consists of two-pyroxene schists and plagiogneisses metamorphosed under granulite-facies conditions. Their chemical composition is consistent with that of a differentiated series of rocks ranging from gabbro to tonalites with abundant alaskitic gneissose granite veins and bodies. The rocks are mainly high-potassium (K2O/Na2O > 0.50), high-magnesium (mg# 50-70), low-titanium (TiO2 0.35-1.31 wt.%) with low TiO2 concentration in clino- and orthopyroxene. Normative olivine makes up 6-9 % of metagabbroic rocks. The rocks display well-defined negative Ti, Nb, Ta, and P anomalies typical of subduction magmatism. The two-pyroxene gneisses show high Sr/Y ratios of 67.6-88 and (La/Yb)N of 24.8-25.6. Saltakh rocks are part of a shoshonite series, as indicated by Nb/La, La/Yb, Th/Nb and Ce/Yb ratios. All the rocks display positive εNd(T) values of 1.9-4.1 and εSr(T) of 0.77-17.8 indicative of a mantle source of magma and T(Nd)DM of 2,20-2,26 Ga. U-Pb zircon dating (SHRIMP II) has shown that the protoliths of Saltakh melanocratic rocks were dated at 2100-2086 Ma, and those of two-pyroxene plagiogneisses of tonalite composition were dated at 2025±7 Ma. Alaskitic gneissose granites were dated at 1969±7 Ma. The study of the trace element composition of zircon has revealed general enrichment in LREE. High LREE concentrations are due to secondary zircon alterations and the shoshonitic pattern of the melt, the high-temperature conditions of crystallization, and an anomalous fluid regime. The geodynamic setting in which the Saltakh Massif was formed was consistent with a pericontinental magmatic arc. The formation of alaskitic gneissose granites was due to anatexis provoked by later collision processes. Saltakh magmatic rocks were formed simultaneously with magmatic rocks from the Khapchan prospect which occur farther south, and were studied earlier (2095±10 Ma tholeiitic metadiorites and 2030±17 Ma calc-alkaline metatonalites). We interpret them as part of a metamorphosed juvenile Paleoproterozoic suprasubduction complex.
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Date submitted2022-07-10
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Date accepted2023-06-20
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Date published2024-02-29
Mathematical modeling of the electric field of an in-line diagnostic probe of a cathode-polarized pipeline
A mathematical model of the in-line control of the insulation resistance state for cathodically polarized main pipelines according to electrometry data is considered. The relevance of the work is caused by the opportunity to create in-line internal isolation defects indicators of the main pipelines for transported liquids that are good conductors and expand the functionality of monitoring and controlling cathodic protection systems of the main pipelines. Features of the mathematical model are: consideration of the electric conductivity of transported liquid influence on electric field distribution; consideration of the influence of external and internal insulating coating resistance; use of the electric field of an in-line diagnostic probe for quality control of internal insulation. Practical significance consists in the development of modeling methods for control subsystems of main pipeline protection against corrosion and the development of special mathematical and algorithmic support systems for monitoring and controlling the operating modes of the cathodic protection station of main pipelines.
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Date submitted2022-03-25
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Date accepted2022-09-06
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Date published2022-12-29
Autoclave modeling of corrosion processes occurring in a gas pipeline during transportation of an unprepared multiphase medium containing CO2
The problem of selecting a method for ensuring the reliability of the unprepared fluid transport facilities of an unprepared fluid in the presence of carbon dioxide is considered. Carbon dioxide corrosion is one of the dangerous types of damage to field and main pipelines. It has been shown that dynamic autoclave tests should be carried out during staged laboratory tests in order to determine the intensity of carbon dioxide corrosion and to select the optimal method of protection. A hypothesis about the imperfection of the existing generally accepted approaches to dynamic corrosion testing has been put forward and confirmed. A test procedure based on the use of an autoclave with an overhead stirrer, developed using elements of mathematical modeling, is proposed. The flows created in the autoclave provide corrosive wear of the sample surface similar to the internal surfaces elements wear of the pipelines piping of gas condensate wells. The autoclave makes it possible to simulate the effect of the organic phase on the flow rate and the nature of corrosion damage to the metal surface, as well as the effect of the stirrer rotation speed and, accordingly, the shear stress of the cross section on the corrosion rate in the presence/absence of a corrosion inhibitor. The given results of staged tests make it possible to judge the high efficiency of the developed test procedure.
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Date submitted2022-04-18
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Date accepted2022-05-25
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Date published2022-07-26
U-Pb (SHRIMP-RG) age of zircon from rare-metal (Li, Cs) pegmatites of the Okhmylk deposit of the Kolmozero-Voron’ya greenstone belt (northeast of the Fennoscandian shield)
The results of isotopic and geochronological study of zircon from rare-metal pegmatites of the Okhmylk deposit are presented. There were no reliable data on the age of lepidolite-spodumene-pollucite pegmatites of this and the other deposits spatially located within the Archean Kolmozero-Voron’ya greenstone belt. The earlier estimates of the pegmatite age indicate a broad time range from 2.7 to 1.8 Ga. Zircon in the studied pegmatites is characterized by inner heterogeneity, where core and rim zones are distinguished. Minor changes are observed in the core zones, they have a spotted structure and contain numerous uranium oxide inclusions. According to X-ray diffraction analysis, zircon crystallinity is preserved completely in these areas. Complete recrystallization with modification of the original U-Pb isotopic system occurred in the zircon rims. New U-Pb (zircon) isotopic and geochronological data of 2607±9 Ma reflect the time of crystallization of pegmatite veins in the Okhmylk deposit. Isotopic data with ages of ~1.7-1.6 Ga indicate later hydrothermal alteration. The obtained results testify to the Neo-Archean age of the formation of the Okhmylk deposit 2.65-2.60 Ga, reflecting the global age of pegmatite formation and associated the world's largest rare-metal pegmatite deposits.
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Date submitted2021-04-19
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Date accepted2022-05-25
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Date published2022-07-13
Development of the technology of stowing the developed space during mining
- Authors:
- Evgenii R. Kovalskii
- Kirill V. Gromtsev
An analysis of the world experience in the development of potash deposits shows that the main problems arising during their development are a high level of mineral losses, an increased risk of flooding of mine workings as a result of water-proof layer discontinuance and the development of emergency water inflows in the mined-out spaces. Reduction of potash ore losses can be achieved by using a long-pillar mining system, but this method is limited by the peculiarities of the geological structure of the potash deposits and the need to preserve the continuity of the water-proof layer during its underworking. The safety of underworking of the water-proof layer can be improved by using the stowing of the developed longwall space. However, the question of the influence of the stowing on the height of the zone of water supply cracks development remains little-studied. The world experience of stowing the developed spaces in the development of layers with long pillars is analyzed and the technology of placing the stowing masses, which can solve these problems, is proposed. The considered technology and the proposed solutions are supported by laboratory tests of stowing materials and mathematical modeling of deformation zones in the overlying rocks.
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Date submitted2021-02-20
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Date accepted2021-10-18
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Date published2021-12-16
Thermal protection implementation of the contact overheadline based on bay controllers of electric transport traction substations in the mining industry
The article presents the principle of thermal protection of the contact overheadlineand substantiates the possibility of practical implementation of this principle for rail electric transport in the mining industry. The algorithm for the implementation of modern digital protection of the contact overhead line as one of the functions of the controller is described. A mathematical model of thermal protection is proposed, which follows from the solution of the heat balance equation. The model takes into account the coefficient of the electrical networktopology, as well as the coefficient of consumption of the current-carrying core of the cable, which determines the reduction in the conducting section from contact erosion and the growth of oxide films. Corrections for air flows are introduced when receiving data from an external anemometer, via telemechanics protocol. The mathematical model was tested by writing a real thermal protection program in the C programming language for the bay controller, based on the circuitry of which is the STM32F407IGT6 microcontroller for the microcontroller unit. Verification tests were carried out on a serial bay controller in 2020. The graphs for comparing the calculated and actual values of temperatures, with different flow rates of the current-carrying conductor of the DC cable, are given. To obtain data, telemechanics protocols IEC 60870-104 and Modbus TCP, PLC Segnetics SMH4 were used.
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Date submitted2021-03-16
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Date accepted2021-07-27
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Date published2021-10-21
Allocation of a deep-lying brine aquifer in the rocks of a chemogenic section based on the data of geophysical well logging and 2D seismic exploration
Advancement in the production of potassium fertilizers is an important strategic task of Russian agricultural industry. Given annually growing production rates, the reserves of discovered potassium-magnesium salt deposits are noticeably decreasing, which creates the need to ensure stable replenishment of the resource base through both the discovery of new deposits and the exploitation of deep-lying production horizons of the deposits that are already under development. In most cases, deposits of potassium-magnesium salts are developed by underground mining. The main problem for any salt deposit is water. Dry salt workings do not require any additional reinforcement and can easily withstand rock pressure, but with an inflow of water they begin to collapse intensively – hence, special attention is paid to mine waterproofing. Determination of spatial location, physical and mechanical properties of the aquifer and water-blocking stratum in the geological section represent an important stage in the exploration of a salt deposit. The results of these studies allow to validate an optimal system of deposit development that will minimize environmental and economic risks. On the territory of Russia, there is a deposit of potassium-magnesium salts with a unique geological structure – its production horizon lies at a considerable depth and is capped by a regional aquifer, which imposes significant limitations on the development process. To estimate parameters of the studied object, we analyzed the data from CDP seismic reflection survey and a suite of methods of radioactive and acoustic well logging, supplemented with high-frequency induction logging isoparametric sounding (VIKIZ) data. As a result of performed analysis, we identified location of the water-bearing stratum, estimated average thickness of the aquifers and possible water-blocking strata. Based on research results, we proposed methods for increasing operational reliability of the main shaft in the designed mine that will minimize the risks of water breakthrough into the mine shaft.
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Date submitted2021-03-05
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Date accepted2021-04-28
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Date published2021-09-20
Rational design justification of the tunnel boring shield executive body for the conditions of the mines of Saint Petersburg Metrostroy
The article discusses the features of running tunnels in difficult mining and geological conditions of the Saint Petersburg Metrostroy using modern tunnel boring shields of Herrenknecht company with hybrid executive bodies equipped with a incisors and rock cutters. The work of a hybrid executive body is analyzed when driving along a heterogeneous bottomhole massif consisting of Cambrian clay with limestone interlayers. Theoretical and experimental studies of vibroactive cones, a graphical representation of the dependence of the depth of their penetration on the axial force and axial force together with the applied shock load (the dependences of the penetration depth are interpreted as a linear dependence) have been carried out. An increase in the intensity of destruction of a heterogeneous bottomhole massif consisting of Cambrian clay and limestone interlayers using vibroactive rock-cutting tools (spiked roller) was theoretically and experimentally confirmed, while the growth of the penetration rate is determined depending on the number of their parameters. The design is considered, the principle of operation and the method of power calculation of a rotary executive body equipped with vibroactive cutters are described, on the basis of which a nomogram of the dependence of the torque and performance of the tunnel boring shield on the feed rate of the executive body to the bottom is built.
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Date submitted2020-10-05
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Date accepted2021-03-30
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Date published2021-06-24
Improving the efficiency of relay protection at a mining and processing plant
The paper presents the results of constructing effective relay protection in the power supply system of a mining and processing plant (MPP). A brief description of the MPP is given, the power supply and substitution circuits used to calculate the short-circuit currents are given. A statistical analysis of failures in the electric network of the MPP has been carried out, which makes it possible to draw conclusions about the nature of failures ranges. Analysis of the registered faults shows that a significant part of them are line-to-earth faults, which in most cases turn into multiphase short circuits, which are interrupted by overcurrent protection. In order to improve the efficiency and reliability of the relay protection, the power supply scheme of the MPP was refined and analyzed. The calculation of the short-circuit currents was made, which made it possible to calculate the settings of the relay protection and give recommendations on the place of its installation and adjustment in order to ensure the normal operation of electricity consumers. To reduce the number of failures to the cable insert on the line leaving the administrative and household complex (AHC), and to increase the reliability of power supply to consumers, it is advisable to divide the capacities of the existing 10 kV line into two parallel ones by laying a second line. It is recommended to install a current cut-off on the line outgoing to the AHC, the feasibility of the installation of which was shown by calculations. This will reduce the chance of failures to the cable gland. Data on the setting currents of overcurrent protection and current cut-off are given on the selectivity card.
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Date submitted2019-07-17
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Date accepted2019-09-04
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Date published2019-12-24
On flood protection measures for potash mines
- Authors:
- A. A. Baryakh
- E. A. Gubanova
Development of water-soluble ore deposits is associated with the necessity to preserve water blocking strata (WBS), which separate aquifers from the mine gob. One indicator of the rate of man-induced load on WBS layers is subsidence of the earth surface, which defines the character of shift trough formation of the earth surface. The greatest threat of WBS discontinuity is posed by the areas located at the edges of a shift trough. From the perspective of Upper Kama deposit of potassium and magnesium salts, by means of mathematical modelling methods authors demonstrated that in the capacity of threat indicators of WBS hole destruction it is possible to use the following parameters of a shift trough: edge length scaled to the depth of mining operations and maximum subsidence of the earth surface. Critical combination of these factors is responsible for the discontinuity at the edges of water blocking strata. These parameters of a shift trough can easily be controlled by instrumental procedures and can be included in the basics of a general monitoring system of WBS state at potash mines. In order to protect the mine from the inrush of fresh water, it is necessary to form softening zones at the edges of mined-out areas near permanent or temporary borders of mining operations. Authors review different options of softening zone formation. Numerical tests have demonstrated that the most efficient way to protect water blocking strata is the formation of softening zones by means of backfilling the stopes of the workable seam or its exclusion from mining operations.
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Date submitted2017-12-27
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Date accepted2018-03-22
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Date published2018-06-22
Mathematical model of heat exchange processes for heat ptotective cooling suit of a rescuer
- Authors:
- V. R. Alabev
- G. V. Zavyalov
Fires are followed by the range of factors hazardous for human health; a radiant thermal stream accompanied by the high temperature of the environment is one of these factors. For protection of firemen special protective clothing from heat impact and the insulation type clothing are used. The paper demonstrates that the concept of action of such clothing is based on the passive heat protection owing to the use of materials with low conducting capacity or high specific heat. The time of effective protection of a suit is not considerable which reduces the duration of work under the unfavorable climatic conditions drastically, increases the work labor input, leads to the hyperthermia. One of the ways focused on the improvement of the heat protective clothing is a design of suits with cooling, which is stated in the paper. The paper shows that the developed heat protective suits on the basis of water-ice cooling elements are not widely used due to considerable costs. A more reasonable idea refers to the design of heat protective suits with cooling by using running water as the most available coolant circulating along polyvinylchloride pipes arranged between the layers of a suit.
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Date submitted2017-09-02
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Date accepted2017-11-22
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Date published2018-02-22
Age and metamorphic conditions of the granulites from Capral-Jegessky synclinoria, Anabar shield
The paper presents the results of the isotope, geochemical and thermobarometric study of plagio-crystalline schist containing in the Upper Anabar series of the Anabar Shield. Granulite complexes of the paleoplatforms are the most important issue in addressing the fundamental problem of the Earth's crust origin and its composition. The early stages of crust formation which correspond to the deeply metamorphosed rocks of the platform basements, available for study within the shields, are of particular interest. The study of the age and metamorphic conditions of granulites by the case of the Upper Ananbar series allows specifying the stages the Anabar Shield's ancient crust formation. Isotope-geochemical (U-Pb geochronology for zircon and Sm-Nd for garnet-amphibole-WR) and thermoba-rometric (Theriak-Domino) studies of plagio-crystalline schist allowed to identify two Paleoproterozoic metamorphism stages within the territory of the Anabar Shield with an age of about 1997 and 1919 million years. The peak conditions of granulite metamorphism are determined as 775±35 С and 7.5±0.7 kbar, the parameters of the regressive stage are 700 C and 7 kbar. The sequence of the rocks metamorphic transformations can be assumed: high-thermal metamorphism of the granulite facies (T ≤ 810 C) and subsequent sub-isobaric (about 7 kbar) cooling to 700 C with a water activity increase and formation of Grt-Amp paragenesis corresponding to the transition from the granulite to amphibolite facies. Data on the REE and other trace elements distribution in zircon and rock-forming minerals obtained by the ion microprobe analysis contribute significantly to the isotope-geochemical data interpretation.
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Date submitted2015-07-30
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Date accepted2015-09-11
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Date published2016-02-24
Principles of corporate communications management system development for mineral resources companies
- Authors:
- A. B. Makhovikov
The article shows the benefits of using unified communications for the management of mineral resources companies and discusses some principles of a modern corporate communications system providing the guaranteed encryption of all transmitted information (voice, text and files). The system structure, its operations and technologies, necessary for the creation of such a system, are substantiated. The secure corporate communication system developed at the National Mineral Resources University (Mining University) is described, and its comparison with other domestic and foreign systems is provided.
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Date submitted2014-11-28
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Date accepted2015-01-13
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Date published2015-10-26
Nanobar code as multi-purpose two-dimensional notation with new features
- Authors:
- E. I. Pryakhin
The article gives an analysis of the current standard two-dimensional codes, showing their features and applications. It was concluded that the feasibility of developing a new type of two-dimensional codes, the Nanobar code (NBC), in which information can be open (available) and, if necessary, closed (unavailable) to the user through the use of cryptographic encryption techniques. At the same time the new codes provide a significant increase in the volume of coded information that allows us to recommend using them as a local database, in particular for the issue of electronic technological certificates and product passports, personal dog tags for the military, athletes and others. It is noted as an important characteristic that the Nanobar code is able to encode different types of digital information. Due to its characteristics, the NBC is proposed to use as an identification number and protect legal products against counterfeiting. Two variants of the NBC technology application are proposed – with laser printing and printer. For reading information from the NBC, special software was developed, including mobile applications that allow using a smartphone to read the NBC. The basic scope of the NBC application was suggested.
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Date submitted2009-08-22
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Date accepted2009-10-19
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Date published2010-02-01
The substantiation of reinforcing support of preparation mines in the ore massive of the Yakovlevskiy deposit
- Authors:
- Yu. N. Antonov
- V. Yu. Sinegubov
The paper justifies a design of reinforcing mine support of the protective roof at the priority high-grade ore mining site of the Yakovlevskiy deposit. Experience of mine roadway support with the KMP-A3 standing support has been analyzed. A reinforcing support is offered consisting of rock bolts back bracing the ore exposure, which best fits with continuous miner roadheading and consolidating stowing (concrete).
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Date submitted2009-07-04
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Date accepted2009-09-10
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Date published2010-04-22
Provision of safe coal mining with due account оf cleanup works at adjacent seams
- Authors:
- M. A. Ilyashov
During planning of mining works with coal series it is important to take into consideration mining conditions of each mine layer, to determine presence of natural and technogenic abnormal areas at its place and to appreciate their potential level of influence on the increase of rock pressure manifestations in the development and productive workings. In comparable conditions the most negative manifestations of rock pressure can be observed in roadways of neighboring low layer, when they are disposed in range of mutual action of abnormal areas of natural and technogenic origins.
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Date submitted2008-11-23
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Date accepted2009-01-30
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Date published2009-12-11
The estimate of the utilization’s efficiency of the production waste products, which appeared as a result of the preservation of the environment measures
- Authors:
- E. M. Pronin
Nowadays the problems of the stable growth of mineral and source of raw materials and fuel and energy complex industries are attached great importance to, since it influences the country social-economic condition. In its turn the development of the mining industry requires opening up new lands, which are especially vulnerable to different kinds of anthropogenous and technogenous factors. The changes in the state of economic system have excluded the lowering expenditure by the economy of the production scale. The typical features of a new economy became the progress of free competition and intensive demonopolization. At the same time for the mining industry it is significant that large-scale enterprises should be the foundation of many cities economies of the Russian Federation. For the way out of a system crisis it is necessary to change the strategy – to alter not only the condition of the system, but its management. The formation of the mining complexes permits to use sources of raw materials of the exploited deposits in the proper way, to process waste products of the basic production into the commodity output, to raise the efficiency and cut costs of the preservation of the environment measures from concentration waste products, exhaust solutions, gases, warm water harmful influence on the environment. The practical use of the production waste products of the mining complexes is unprofitable and makes sense only because of its opportunity partially compensating the aggregate investments for the preservation of the environment. The estimate of the utilization s efficiency of the production waste products has made.