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Date submitted2023-10-28
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Date accepted2024-11-07
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Date published2025-02-25
Radiation characteristics of coals at different stages of metamorphism
The formation of deposits and subsequent metamorphic processes that affect concentrations of radioactive elements in coal can indicate ongoing geological activities, therefore, analyzing trends in the radiation characteristics of coal throughout the metamorphic series is highly relevant. The aim of this work is to experimentally evaluate the radiation characteristics of different coal ranks (metamorphic stages) using thermoluminescent (TL) dosimetry and beta activity measurements, and to identify correlations between these radiation characteristics and data obtained from technical, elemental, and thermogravimetric analyses, as well as mass spectrometric and electron paramagnetic resonance spectroscopy (EPR) measurements. For dosimetric measurements that indirectly characterize the content of radionuclides in coal, a modified dosimetric complex and original soil-equivalent thermoluminescent detectors based on SiO2 were used. The analysis of the obtained results supports the use of TL studies to determine the ash content of coals at low and medium stages of metamorphism (coal rank B→G), while indicating that this method is not feasible for coals at higher stages of metamorphism. The correlation dependencies in the metamorphism series suggest abrupt change in the conditions of coal formation during the time range corresponding to transformation from high to low volatile bituminous coals (coal rank G→Zh→K). These abrupt changes in regional metamorphism conditions (time, temperature, pressure, oxidation-reduction conditions) are confined to the boundary of the Permian and Triassic periods (~250 million years ago), during which both the transformation of existing coal deposits and the formation of new deposits occurred.
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Date submitted2023-07-31
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Date accepted2024-11-07
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Date published2025-02-25
Environmental assessment of biochar application for remediation of oil-contaminated soils under various economic uses
- Authors:
- Tatiana V. Minnikova
- Sergey I. Kolesnikov
Remediation is an important area of oil-contaminated soil restoration in Russia, since oil refining industry is the major one for Russia and neighbouring countries, and the issues of environmentally effective and economically profitable remediation of oil contamination have not yet been solved. Soils under various economic uses have different surface areas and degrees of soil particles envelopment with oil due to the presence or absence of cultivation, the amount of precipitation and plant litter. The introduction of various substances for remediation into oil-contaminated soils of steppes (arable land), forests, and semi-deserts, considering their differences, gives different results. Biochar is coal obtained by pyrolysis at high temperatures and in the absence of oxygen. The uniqueness of this coal lies in the combination of biostimulating and adsorbing properties. The purpose of the study is to conduct an environmental assessment of biochar application for remediation of oil-contaminated soils under various economic uses. The article compares the environmental assessments of biochar application in oil-contaminated soils with different particle size fraction. The following indicators of soil bioactivity were determined: enzymes, indicators of initial growth and development intensity of radish, microbiological indicators. We found that the most informative bioindicator correlating with residual oil content is the total bacteria count, and the most sensitive ones are the roots length (ordinary chernozem and brown forest soil) and the shoots length (brown semi-desert soil). The use of biochar on arable land and in forest soil (ordinary chernozem and brown forest soil) is less environmentally efficient than in semi-desert soil (brown semi-desert soil). The study results can serve to develop measures and managerial and technical solutions for remediation of oil-contaminated soils under various economic uses.
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Date submitted2024-07-28
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Date accepted2024-11-26
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Date published2024-12-12
From import substitution to technological leadership: how local content policy accelerates the development of the oil and gas industry
- Authors:
- Oleg V. Zhdaneev
- Ivan R. Ovsyannikov
Achieving technological sovereignty implies accelerating innovation and reducing import dependence. An effective tool for addressing these challenges is local content policy (LCP). The purpose of this study is to assess the impact of LCP on innovation activity in oil and gas companies and to provide recommendations for enhancing the effectiveness of this policy in Russia. The paper analyzes the influence of LCP on innovation levels in the oil and gas sector, drawing on examples from 10 countries. A positive short-term impact of LCP on innovation was identified in Brazil, Malaysia, and Saudi Arabia, with long-term effects observed in China and South Africa. Recommendations for improving the effectiveness of LCP in Russia are supplemented with a methodology for calculating the level of technological sovereignty. A refinement of the method for solving the «responsiveness» problem, incorporating the level of localization, has been proposed.
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Date submitted2024-04-24
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Date accepted2024-09-24
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Date published2024-11-12
Study and justification of the combination of beneficiation processes for obtaining flake graphite from technogenic carbon-containing dusts
The most important task of modern production development is to provide the mineral and raw materials sector of the economy with resources included in the list of strategic raw materials, including flake graphite. In addition to natural raw materials, the source of its obtaining can be metallurgical production wastes not involved in processing. Development of metallurgical dust beneficiation technology will solve the problem of obtaining high-purity flake graphite with a crystal structure close to ideal and in demand in the production of high-tech materials. It will allow creating a renewable raw material base of graphite and utilising metallurgical production wastes. The research included the study of dust beneficiation by coarseness, magnetic and flotation methods, the influence of dust disintegration processes on beneficiation indicators. Based on the established technological properties of the components of dusts, magnetic, flotation and gravity beneficiation methods can be applied for their separation in different sequence. It is shown that dusts from different sites have different enrichability by these methods, and it should be taken into account when developing a complex technology of their processing. The degree of beneficiation increases in a row of dusts from the blast furnace shop (BF) – electric steel smelting shop (ESS) – oxygen-converter shop (OCS). The method of grinding has a significant influence on the separation indicators – at dry grinding in a centrifugal-impact mill with subsequent pneumatic classification the quality of graphite concentrates increases by 22.7 % of carbon for BF dust and by 13.48 % of carbon for ESS dust. OCS dust beneficiation indicators are high at coarse grinding with steel medium – mass fraction of carbon 96.1 %.
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Date submitted2024-06-17
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Date accepted2024-07-17
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Date published2024-10-03
Justification on the safe exploitation of closed coal warehouse by gas factor
The annual increase of coal production and its demand lead to the necessity in temporary storage places (warehouses) organization to accommodate raw coal materials before the shipment. It is noted that at the open method of coal storing the dust emission from loading/unloading operations and from the pile surface effects negatively the health of the warehouse workers and adjacent territories. An alternative solution is closed-type warehouses . One of the main hazards of such coal storage can be the release of residual methane from coal segregates into the air after degassing processes during mining and extraction to the surface, as well as transportation to the place of temporary storage. The study carries the analysis of methane content change in coal during the processes of extraction, transportation and storage. Physical and chemical bases of mass transfer during the interaction between gas-saturated coal mass and air are studied. It is determined that the intensity of methane emission depends on: the coal seam natural gas content, parameters of mass transfer between coal, and air and the ambient temperature. The dynamics of coal mass gas exchange with atmospheric air is evaluated by approximate approach, which is based on two interrelated iterations. The first one considers the formation of methane concentration fields in the air space of the bulk volume and the second accounts the methane emission from the pile surface to the outside air. It is determined that safety of closed coal warehouses exploitation by gas factor can be ensured by means of artificial ventilation providing volumetric methane concentration in the air less than 1 %. The flow rate sufficient to achieve this methane concentration was obtained as a result of computer modeling of methane concentration fields formation in the air medium at theoretically calculated methane emission from the pile surface.
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Date submitted2023-07-05
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Date accepted2024-06-03
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Date published2024-12-25
Complete extraction of conditioned ores from complex-structured blocks due to partial admixture of substandard ores
- Authors:
- Bayan R. Rakishev
The paper presents mining-technological substantiation of complete extraction of conditioned ores from complex-structured blocks of benches by mixing a layer of substandard ores of certain sizes. The relevance of the work consists in the development of innovative methods of establishing the parameters of the substandard layer of ores to be added to the conditioned ores. The main problem is to ensure complete extraction of useful components into concentrate from shipped ore with acceptable deviations from the required ones. A new typification of complex-structured ore blocks of the bench has been carried out. Analytical dependences of mining and geological characteristics of complex-structured ore blocks were obtained. Theoretical dependences for determining the main indicators of mineral processing are derived. Analytical dependences for determination of the content of useful component in shipped ore α' – mixture of conditioned ore with the content of useful component α and admixed layer of substandard ore with the content of useful component α'' are offered. For the first time in mining science, a new approach of complete extraction of conditioned ores from complex-structured blocks of benches by grabbing a certain part of substandard ores during excavation, increasing the volume of extracted ore and expanding the extraction of useful components in the concentrate has been substantiated. The increment of useful components can reach 10-15 % of the total volume of extraction, which allows predicting a significant increase in the completeness of mineral extraction from the Earth's interior.
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Date submitted2024-04-25
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Date accepted2024-06-13
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Date published2024-07-11
Evaluation of the effectiveness of neutralization and purification of acidic waters from metals with ash when using alternative fuels from municipal waste
- Authors:
- Polina A. Kharko
- Aleksandr S. Danilov
The problem of pollution of natural water objects with heavy metals is extremely relevant for the areas where industrial enterprises are located. Unauthorized discharge of contaminated wastewater, inefficient operation of sewage treatment plants, as well as leakage of drainage waters from man-made massifs lead to changes in the hydrological system affecting living objects. The article studies the composition of ash from the combustion of alternative fuels from municipal waste, and also considers the possibility of using it to neutralize sulfuric acid drainage waters and extract metal ions (Cu, Cd, Fe, Mn, Zn) from them. It has been established that the efficiency of water purification from metals depends on the pH value achieved during the purification process. The pH value is regulated by the dose of the introduced ash, the contact time and depends on the initial concentration of metal ions and sulfates in the solution. Studies on the neutralization and purification of a model solution of sulfuric acid drainage waters of a tailings farm of known composition have shown that in order to achieve a pH of 8-9, optimal for precipitation of metal hydroxides Cu, Cd, Fe, Mn, Zn and Al washed out of ash, and water purification with an efficiency of 96.60 to 99.99 %, it is necessary to add 15 g/l of ash and stir the suspension continuously for 35 minutes. It was revealed that exposure to ash with sulfuric acid waters leads to the transition of water-soluble forms of metals into insoluble ones and their “cementation” with calcium sulfate. The amount of Zn and Fe ions washed out of the ash decreases by 82 and 77 %, Al, Cd, Cu, Mn – by 25 %. This reduces the toxicity of ash, which is proved by a decrease in the toxic multiplicity of dilution of the water extract by 14 times.
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Date submitted2021-05-08
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Date accepted2022-07-21
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Date published2023-12-25
Technologies of intensive development of potash seams by longwall faces at great depths: current problems, areas of improvement
- Authors:
- Vladimir P. Zubov
- Denis G. Sokol
The results of the analysis of practical experience in the development of potash seams using longwall mining systems at the mines of OAO “Belaruskali” are presented. Positive changes in the technical and economic indicators of mines and an increase in the safety of mining operations were noted with the introduction of resource-saving technologies without leaving the pillars between the excavation columns or with leaving the pillars between the columns with dimensions at which they are destroyed by mining pressure in the goaf. It is noted that the use of mechanized stoping complexes characterized by high energy capacity, combined with large depths of development, is the main reason for the temperature increase in longwalls to values exceeding the maximum permissible air temperature regulated by sanitary standards. Based on production studies, it was concluded that the temperature regime along the length of the longwall face is determined by the temperature of rocks in the developed longwall space, heat emissions from the equipment of the power train, and the temperature of the rock mass ahead of the longwall. The conclusion has been drawn about the feasibility of using developed technological schemes in deep mining conditions, which provide a reduction in longwall temperature by 6-9 °C or more through isolated ventilation of longwall and power trains, as well as heat exchange between the airflow entering the longwall and the rocks in the developed space.
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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 submitted2022-10-31
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Date accepted2023-03-02
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Date published2023-12-25
Lightweight ash-based concrete production as a promising way of technogenic product utilization (on the example of sewage treatment waste)
- Authors:
- Tatyana E. Litvinova
- Denis V. Suchkov
The study is devoted to the development of a method for the technogenic raw materials utilization. Special attention is paid to the prospect of involving products based on them in the production of new building materials. The results of Russian and foreign studies on the reuse of wastes, such as phosphogypsum, metallurgical slag, waste from municipal and industrial wastewater treatment, etc., in the building materials industry are considered. It has been established that the use of incinerated sewage sludge ash in construction is a promising direction in terms of environmental and economic efficiency. The research confirmed the compliance of the lightweight ash-based concrete components to the regulatory documentation requirements for a number of indicators. As a result of the research, the composition of the raw mixture for the lightweight concrete production with incinerated sewage sludge ash as a replacement for a part of the cement has been developed. In terms of parameters, the developed concrete corresponds to standard lightweight concrete, marked in accordance with the regulatory documents of the Russian Federation as D1300 (density not less than 1.3 g/cm3), Btb2 (flexural strength not less than 2 MPa), M200/B15 (compressive strength not less than 15 MPa). Lightweight ash-based concrete is suitable for use in construction, repair of roads and improvement of urban areas.
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Date submitted2022-04-15
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Date accepted2022-11-17
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Date published2023-04-25
Uranium in man-made carbonates on the territory of Ufa
The paper presents the results of analyzing uranium content in man-made carbonates (scale crusts) on the territory of Ufa based on examination of 42 samples. The median uranium content in the investigated samples stands at 1.44 mg/kg, which is significantly lower than the background values (scales from the Lake Baikal water, a clarke of sedimentary carbonate rocks) and data on other settlements of the Republic of Bashkortostan. Low values of uranium content are probably associated with the effects of the three leading factors, i.e. specific subsurface geology of the territory (gypsum, limestone); types of water supply; water treatment processes for the centralized type of water supply. Spatial distribution of uranium in man-made carbonates is characterized with uniformity, which is disturbed in two cases, i.e. a change of the water supply type (from centralized to individual); and material of the vessels used for boiling the water. No significant differences were detected when comparing samples of man-made carbonates associated with different sources of water supply (the bucket and infiltration types of water intake) and the types of household filters.
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Date submitted2022-05-13
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Date accepted2022-09-24
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Date published2022-11-03
Rapid detection of coal ash based on machine learning and X-ray fluorescence
Real-time testing of coal ash plays a vital role in the chemical, power generation, metallurgical, and coal separation sectors. The rapid online testing of coal ash using radiation measurement as the mainstream technology has problems such as strict coal sample requirements, poor radiation safety, low accuracy, and complicated equipment replacement. In this study, an intelligent detection technique based on feed-forward neural networks and improved particle swarm optimization (IPSO-FNN) is proposed to predict coal quality ash content in a fast, accurate, safe，and convenient manner. The data set was obtained by testing the elemental content of 198 coal samples with X-ray fluorescence (XRF). The types of input elements for machine learning (Si, Al, Fe, K, Ca, Mg, Ti, Zn, Na, P) were determined by combining the X-ray photoelectron spectroscopy (XPS) data with the change in the physical phase of each element in the coal samples during combustion. The mean squared error and coefficient of determination were chosen as the performance measures for the model. The results show that the IPSO algorithm is useful in adjusting the optimal number of nodes in the hidden layer. The IPSO-FNN model has strong prediction ability and good accuracy in coal ash prediction. The effect of the input element content of the IPSO-FNN model on the ash content was investigated, and it was found that the potassium content was the most significant factor affecting the ash content. This study is essential for real-time online, accurate, and fast prediction of coal ash.
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Date submitted2022-02-26
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Date accepted2022-04-27
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Date published2022-07-26
Type intrusive series of the Far East belt of lithium-fluoric granites and its ore content
- Authors:
- Viktor I. Alekseev
The evolution and ore content of granitoid magmatism in the Far East belt of lithium-fluoric granites lying in the Russian sector of the Pacific ore belt have been studied. Correlation of intrusive series in the Novosibirsk-Chukotka, Yana-Kolyma and Sikhote-Alin granitoid provinces of the studied region allowed to establish the unity of composition, evolution, and ore content of the Late Mesozoic granitoid magmatism. On this basis, a model of the type potentially ore-bearing intrusive series of the Far East belt of lithium-fluoric granites has been developed: complexes of diorite-granodiorite and granite formations → complexes of monzonite-syenite and granite-granosyenite formations → complexes of leucogranite and alaskite formations → complexes of rare-metal lithium-fluoric granite formation. The main petrological trend in granitoid evolution is increasing silicic acidity, alkalinity, and rare-metal-tin specialization along with decreasing size and number of intrusions. At the end of the intrusive series, small complexes of rare-metal lithium-fluoric granites form. The main metallogenic trend in granitoid evolution is an increasing ore-generating potential of intrusive complexes with their growing differentiation. Ore-bearing rare-metal-granite magmatism of the Russian Far East developed in the Late Cretaceous and determined the formation of large tungsten-tin deposits with associated rare metals: Ta, Nb, Li, Cs, Rb, In in areas with completed intrusive series. Incompleteness of granitoid series of the Pacific ore belt should be considered as a potential sign of blind rare-metal-tin mineralization. The Far East belt of lithium-fluoric granites extends to the Chinese and Alaskan sectors of the Pacific belt, which allows the model of the type ore-bearing intrusive series to be used in the territories adjacent to Russia.
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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 submitted2021-09-02
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Date accepted2022-01-24
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Date published2022-04-29
Complex processing of high-carbon ash and slag waste
The paper considers a current issue of ash and slag processing for the Polyus Aldan JSC, that has accumulated over 1 million tons of this waste. Following the results of the review of Russian and foreign literature, four promising areas of their use were selected: road construction, building materials, reclamation of disturbed lands, and inert aggregates. To assess the possibility of implementing the selected disposal directions, the samples of ash and slag waste of the enterprise were sampled and analyzed. Fuel characteristics, chemical and mineral composition, as well as physico-chemical and mechanical properties of waste were determined. Taking into account the results of complex laboratory studies and the requirements of regulatory documents, each of the selected areas of using ash and slag waste was evaluated. It was found that their disposal by traditional methods has limitations, mainly related to the high content of unburned fuel residues. The high content of combustible substances and the high specific heat of combustion with a relatively low ash content suggested the possibility of thermal disposal of the studied waste. Based on the literature data, the characteristics of the preparation of organic coal-water suspensions based on the studied ash and slag waste were selected. As a result of a series of experiments on their flaring, the expediency of using the obtained fuel at the enterprise under consideration has been proved. The authors note the possibility of using ash obtained after thermal waste disposal in the road construction industry. The prospects for further research of technologies for the preparation and combustion modes of suspension fuel based on ash and slag waste are determined.
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Date submitted2020-12-08
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Date accepted2021-10-18
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Date published2021-12-16
Prospects for the oil and gas content of the Upper Permian deposits of the southwestern part of the Vilyui syneclise based on the analysis of sedimentary environments and geochemical conditions of oil and gas content
The article discusses the prospects for the oil and gas content of the Upper Permian deposits in the southwestern marginal part of the Vilyui syneclise. In this margin, the Permian terrigenous complex with proven oil and gas productivity in the central part of the syneclise, pinches out. The study area, represented by the monoclinal slopes of the Vilyui syneclise, is considered a promising area for the exploration of non-structural hydrocarbon traps in the Upper Paleozoic sediments. The objectives of the study include identifying general patterns of sediment formation, associated mainly with the development of the alluvial complex, and substantiating the potential opportunities of migration and accumulation of hydrocarbons in the predicted traps. The research is based on the interpretation of the latest seismic surveys and prior-years geological and geophysical data. Authors carried out structural and paleo-structural analysis, identified lithofacies in the well log, generalized and analyzed the geochemical conditions of the oil and gas content of the Upper Permian deposits, traced the pinching out of the Upper Permian deposits on the southwestern margin of the syneclise, and also outlined areas of river valleys development that form zones of advanced reservoirs. The results of the studies have validated promising oil and gas accumulation zones on the southwestern slopes of the syneclise associated with non-anticlinal hydrocarbon traps. Authors also drew up a diagram of the oil and gas potential of the Upper Permian deposits. The obtained results are of interest for prospecting for oil and gas in the area under study.
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Date submitted2020-11-11
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Date accepted2021-03-02
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Date published2021-04-26
Oil and gas content of the understudied part in the northwest of the Timan-Pechora oil and gas province according to the results of basin modeling
Comprehensive interpretation of the results for regional seismic operations and reinterpretation of archived seismic data, their correlation with the drilling data of more than 30 deep wells, including Severo-Novoborsk parametric well, made it possible to clarify the structural maps and thickness maps of all seismic facies structures developed in the territory and water area in the junction of the north of Izhma-Pechora depression and Malozemelsko-Kolguevsk monocline of Timan-Pechora oil and gas province. Data obtained were used at basin modeling in TemisFlow software in order to reconstruct the conditions of submersion and transformation of organic substance in potential oil and gas bearing formations. Modeling made it possible to get an idea of the time and conditions for the formation of large zones of possible hydrocarbons accumulation, to establish space-time connections with possible sources of generation, to identify the directions of migration and on the basis of comparison with periods of intense generation, both from directly located within the operation area and outside them (taking into account possible migration), to identify zones of paleoaccumulation of oil and gas. Work performed made it possible to outline promising oil and gas accumulation zones and identify target objects for further exploration within the site with an ambiguous forecast and lack of industrial oil and gas potential.
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Date submitted2020-05-08
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Date accepted2020-06-12
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Date published2020-12-29
Gas-dynamic roof fall during the potash deposits development
In the development of practically all potash salt deposits, the study of gas-dynamic phenomena (GDP) is one of the most difficult tasks to ensure mining safety. Sudden salt and gas outbursts, dynamic breakdown, which are accompanied by intense gas release and possible broken rock carry-over into the mine workings, are associated with GDP. Geological preconditions for the GDP development are often the layered structure of the salt rock mass, the presence of interlayers and layers of salt clays. For the conditions of the Usolsky potash plant mine, complex studies of factors that characterize the possibility of gas-dynamic roof fall of the stoping rooms were carried out. In mine studies, free gases pressure and the initial velocity of gas release in the rocks of the roof workings were determined. The obtained experimental estimations were used as a parametric basis for mathematical modeling of geomechanical processes under conditions of a near-contact accumulation of free gas. The deformation of a layered salt mass produced by a room development system was described by the model of an ideal elastic-plastic medium with internal friction. The parabolic envelope of Mohr circles was used as a plasticity criterion in the compression area. In the numerical implementation, the deformation of clay contacts was modeled by Goodman contact elements. Based on the results of multivariate numerical calculations, it is established that the main factors determining the possibility of implementing GDP are the additional gas pressure at the contact, the width of the workingspan, and the distance from the roof to the first gas-containing contact. With multi-level lamination of roof rocks, there is a danger of large sources of GDP formation and the mechanism of successive fall of layers in an instant mode is implemented.
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Date submitted2019-07-22
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Date accepted2020-01-04
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Date published2020-04-24
“Ural-20R” combines loading drives evaluation in two-stage development of the face
The technological features of the use of high-performance Ural-20R combines in the conditions of potash mines in Russia are described. It is shown that when the capacity of the worked potash seams is over 4 m, a two-layer ore extraction is used. The formation of cutting process, implemented by the second course of the combine in the treatment chamber, is carried out by an incomplete section of the executive bodies. The standard control system, display and protection of the Ural-20R combine does not allow monitoring and reliable estimation of the magnitude of dynamic components on the drives of the mining machine loads, as well as tracking the feed rate of the combine to the face. The regulation of the operating parameters and the assessment of the degree of loading of the drives of the excavating machine in real time are assigned to the operator. The fundamentals of the experimental research methodology for assessing the loading of drives of Ural-20R combines with the destruction of the potash mass by an incomplete section of the executive bodies are described. The device and the operating procedure of the “Vatur” software-recording complex, which measures, records and records the electrical parameters of the drive motors of a mining machine, is described. The process studies results of forming loads on drive elements of Ural-20R combines when mining a face with an incomplete section of executive bodies are presented. It is proved that the work of combine harvesters on the undercut of the formation with a high feed rate is accompanied by significant dynamic loads on the drives of planetary organs and an overload of the drives of the Berm organs, which leads to an accelerated consumption of the resource and emergency failures of the gearboxes and motors of the extraction machine.
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Date submitted2019-05-14
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Date accepted2019-07-05
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Date published2020-04-24
Development of spacer fluids and cement slurries compositions for lining of wells at high temperatures
Article is devoted to creation of new compositions of process solutions for lining of directional wells at high temperatures. Developed compositions provide high durability characteristics of cement stone. It is shown that with an increase in packing density of cementing slurry components durability characteristics increase and porosity and permeability of cement stone decrease, whereas an increase in temperature and pressure leads to a significant increase in compressive and bending durability, which is associated with presence of quartz in them. It has been established that introduction of special structure-forming additives to the composition of developed cementing solutions allows formation of sedimentation-resistant cement systems that can provide an increase in durability characteristics of cement stone and, in general, quality lining of directional wells. Study of rheological properties of developed cementing compositions showed that the systems have high yield strength at increased temperatures and pressures. Developed compositions of water-based spacer fluids increase the cleansing degree for both casing and rocks surfaces from mud and clay cake residues, which improves the cementing quality of oil and gas wells. Mechanism for increasing the washing ability of spacer fluids and durability characteristics of cement stone, depending on composition and properties of their constituent components, is disclosed.
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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 submitted2019-05-26
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Date accepted2019-07-23
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Date published2019-10-23
Ensuring Stability of Undermining Inclined Drainage Holes During Intensive Development of Multiple Gas-Bearing Coal Layers
At high rates of production face advance, requirements towards reliable operation of undermining drainage holes get raised. The issue of maintaining high intensity of gaseous seams development under naturally increasing gas content, mining depth and capacity of production equipment poses a problem. The greatest threat comes from the loss of hole stability in the bearing pressure affected zone (in front of the face) and in the intensive shift area of overhanging rock corbels (behind the face). Intensification of air leaks due to deformation of borehole channel leads to impoverishment of removed methane-air mixture and an increasing risk to disturb safe aerogas regime in the mining area. The paper describes a mechanism of how coal-face operations affect the state of underground holes and formation of overhanging rock corbels. A typification of basic kinds of borehole deformations is presented. Authors point out critical disadvantages of the most widely-used technological schemes of gaseous seams development under high load on the production face, which hinder normal operation of a gas drainage system. As a result of research, a dependency of shot hole number, as well as the distance between shot hole axes and the borehole, on the stress state of the borehole outline has been defined more precisely. Basing on that, a formula to calculate drilling parameters of the discharge hole system has been suggested. Implementation of these measures will allow to increase the efficiency of underground gas drainage and to maintain growing intensity of gaseous coal seam development.
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Date submitted2018-12-25
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Date accepted2019-03-08
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Date published2019-06-25
Determination of the operating time and residual life of self-propelled mine cars of potassium mines on the basis of integrated monitoring data
Statistical data on the reliability of self-propelled mine cars (SPMC), operating in the potassium mines of the Verkhnekamskoye potassium and magnesium salts deposit are analyzed. Identified the main nodes that limit the resource SPMC. It has been proven that the most common failures of self-propelled cars are the failure of wheel hubs, bevel gears and traveling electric motors. The analysis of the system of maintenance and repair of mine self-propelled cars. It is indicated that the planning and preventive system of SPMC repairs is characterized by low efficiency and high material costs: car maintenance is often carried out upon the occurrence of a failure, which leads to prolonged downtime not only of a specific haul truck, but of the entire mining complex. A method for assessing the technical condition of the electromechanical part of a mine self-propelled car by the nature of power consumption is proposed. This method allows you to control the loading of the drives of the mine self-propelled car, as well as to assess the technical condition of the drives of the delivery machines in real time. Upon expiration of the standard service life of a mine propelled car specified in the operational documentation, its further operation is prohibited and the car is subject to industrial safety expertise. As part of the examination, it is necessary to determine the operating time and calculate the service life of a mine self-propelled car outside the regulatory period. A method has been developed for determining the residual service life of mine car on the basis of instrumentation control data in the conditions of potash mines.
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Date submitted2018-07-15
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Date accepted2018-09-07
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Date published2018-12-21
Justification of rational methods for provision of air to faces of operating coal mines of Vietnam during deepening of mines
- Authors:
- S. G. Gendler
- Tkhe Kha Nguen
Based on the analysis of the mining and geological conditions for developing coal deposits in Vietnam, the existing mining safety regulations, the application of methods for calculating the air supply of working and development faces using the methane factor and modern methods of mathematical modeling of the ventilation of mines threr was developed the procedure for analyzing the efficiency of air distribution management considering the proposed indicator - energy efficiency coefficient for ventilation systems, determined by the efficiency of air use and energy consumption. Relations have been obtained that determine the relationship between the aerodynamic resistance of negative regulators, the number of simultaneously developed working and development faces, the performance of main ventilation fans and the consumed electric power.
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Date submitted2018-05-24
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Date accepted2018-07-20
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Date published2018-10-24
Moisture content of natural gas in bottom hole zone
- Authors:
- E. A. Bondarev
- I. I. Rozhin
- K. K. Argunova
For the traditional problem of gas flow to a well in the center of circular reservoir, the influence of initial reservoir conditions on dynamics of gas moisture content distribution has been determined. Investigations have been performed in the framework of mathematical model of non-isothermal real gas flow through porous media where heat conductivity was considered to be negligible in comparison with convective heat transfer. It is closed by empirical correlation of compressibility coefficient with pressure and temperature, checked in previous publications. Functional dependence of moisture content in gas on pressure and temperature is based on empirical modification of Bukacek relation. Numerical experiment was performed in the following way. At first step, axisymmetric problem of non-isothermal flow of real gas in porous media was solved for a given value of pressure at the borehole bottom, which gives the values of pressure and temperature as functions of time and radial coordinate. Conditions at the outer boundary of the reservoir correspond to water drive regime of gas production. At the second step, the calculated functions of time and coordinate were used to find the analogous function for moisture content. The results of experiment show that if reservoir temperature essentially exceeds gas – hydrate equilibrium temperature than moisture content in gas distribution is practically reflects the one of gas temperature. In the opposite case, gas will contain water vapor only near bottom hole and at the rest of reservoir it will be almost zero. In both cases, pressure manifests its role through the rate of gas production, which in turn influences convective heat transfer and gas cooling due to throttle effect.