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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 submitted2021-07-05
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Date accepted2022-11-17
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Date published2022-12-29
Determination of suitable distance between methane drainage stations in Tabas mechanized coal mine (Iran) based on theoretical calculations and field investigation
A large amount of gas is emitted during underground mining processes, so mining productivity decreases and safety risks increase. Efficient methane drainage from the coal seam and surrounding rocks in underground mines not only improves safety but also leads to higher productivity. Methane drainage must be performed when the ventilation air cannot dilute the methane emissions in the mine to a level below the allowed limits. The cross-measure borehole method is one of the methane drainage methods that involves drilling boreholes from the tailgate roadway to an un-stressed zone in the roof or floor stratum of a mined seam. This is the main method used in Tabas coal mine N 1. One of the effective parameters in this method is the distance between methane drainage stations, which has a direct effect on the length of boreholes required for drainage. This study was based on the measurement of ventilation air methane by methane sensors and anemometers placed at the longwall panel as well as measuring the amount of methane drainage. Moreover, in this study, the obtained and analyzed data were used to determine the suitable distance between methane drainage stations based on the cross-measure borehole method. In a field test, three borehole arrangements with different station distances in Panel E4 of Tabas coal mine N 1 were investigated. Then, the amounts of gas drained from these arrangements were compared with each other. The highest methane drainage efficiency was achieved for distances in the range of 9-12 m between methane drainage stations.
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Date submitted2021-10-14
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Date accepted2022-04-07
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Date published2022-04-29
The influence of the shape and size of dust fractions on their distribution and accumulation in mine workings when changing the structure of air flow
The results of the analysis of statistical data on accidents at Russian mines caused by explosions in the workings space have shown that explosions of methane-dust-air mixtures at underground coal mines are the most severe accidents in terms of consequences. A detailed analysis of literature sources showed that in the total number of explosions prevails total share of hybrid mixtures, i.e. with the simultaneous participation of gas (methane) and coal dust, as well as explosions with the possible or partial involvement of coal dust. The main causes contributing to the occurrence and development of dust-air mixture explosions, including irregular monitoring of by mine engineers and technicians of the schedule of dust explosion protective measures; unreliable assessment of the dust situation, etc., are given. The main problem in this case was the difficulty of determining the location and volume of dust deposition zones in not extinguished and difficult to access for instrumental control workings. Determination of the class-shape of coal dust particles is a necessary condition for constructing a model of the dust situation reflecting the aerosol distribution in the workings space. The morphological composition of coal mine dust fractions with dispersion less than 0.1 has been studied. Particle studies conducted using an LEICA DM 4000 optical microscope and IMAGE SCOPE M software made it possible to establish the different class-shapes of dust particles found in operating mines. It was found that the coal dust particles presented in the samples correspond to the parallelepiped shape to the greatest extent. The mathematical model based on the specialized ANSYS FLUENT complex, in which this class-form is incorporated, is used for predicting the distribution of explosive and combustible coal dust in the workings space. The use of the obtained model in production conditions will allow to determine the possible places of dust deposition and to develop measures to prevent the transition of coal dust from the aerogel state to the aerosol state and thereby prevent the formation of an explosive dust-air mixture.
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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 submitted2021-01-21
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Date accepted2021-04-19
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Date published2021-04-26
Justification of the use of a vegetal additive to diesel fuel as a method of protecting underground personnel of coal mines from the impact of harmful emissions of diesel-hydraulic locomotives
Equipment with diesel engines is used in all mining enterprises. Monorail diesel transport is of great importance in coal mines, as it facilitates the heavy labor of workers when transporting materials and people, fixing mining workings, refueling and repairing equipment, which leads to an increase in the speed of tunneling operations. Reducing the concentration of harmful gases from diesel-hydraulic locomotives at the workplaces of coal mine locomotive drivers can be ensured by the use of additives to diesel fuel that reduce the volume of harmful gas emissions during the operation of diesel-hydraulic locomotives. Additive ester-based on vegetal oil in the amount of 5 mass % in a mixture with hydrotreated diesel fuel reduces the concentration of carbon monoxide by 19-60 %, nitrogen oxides by 17-98 %, depending on the operating mode of the engine, the smoke content of the exhaust gases is reduced to 71 %. There is an improvement in working conditions at the workplace of the driver of a diesel-hydraulic locomotive by the chemical factor due to the reduction of the class of working conditions from 3.1. to 2.
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Date submitted2020-05-12
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Date accepted2020-09-22
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Date published2020-11-24
Design features of coal mines ventilation using a room-and-pillar development system
- Authors:
- Sergey S. Kobylkin
- Alexander R. Kharisov
The safety of mining operations in coal mines for aerological factors depends on the quality of accepted and implemented ventilation design solutions. The current “Design Manual of coal mine ventilation” do not take into account the features of room-and-pillar development systems used in Russia. This increases the risk of explosions, fires, and gassing. The detailed study of foreign experience in designing ventilation for the considered development systems e of coal deposits allowed to formulate recommendations on the ventilation scheme organization for coal mines using a room-and-pillar development system and the procedure for ventilation during multi-entry gateroad development. Observations have shown that the use of the existing Russian procedure for airing mining sites with a room-and-pillar development system complicates the emergency rescue operations conduct. Low speeds and multidirectional air movement, difficult heat outflow, and the abandonment of coal pillars increase the risk of occurrence and late detection of endogenous fire. The results of numerical modeling have shown that the installation (parallel to the drifts) of ventilation structures in inter-chamber pillars will increase the reliability of ventilation by transferring the ventilation scheme from a complex diagonal to a complex parallel. It will also reduce the amount of air required for the mine site and the total aerodynamic drag. The research made it possible to formulate requirements for the design procedure for coal mines ventilation using a room-and-pillar development system, which consist in the order of working out blocks in the panel, and also the additional use of ventilation structures (light brattice clothes or blowing line brattice).
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Date submitted2019-01-03
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Date accepted2019-03-23
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Date published2019-06-25
Normalization of thermal mode of extended blind workings operating at high temperatures based on mobile mine air conditioners
Thermal working conditions in the deep mines of Donbass are the main deterrent to the development of coal mining in the region. Mining is carried out at the lower technical boundaries at a depth of almost 1,400 m with a temperature of rocks of 47.5-50.0 °C. The air temperature in the working faces significantly exceeds the permissible safety standards. The most severe climatic conditions are formed in the faces of blind development workings, where the air temperature is 38-42 °С. It is due to the adopted coal seam mining systems, the large remoteness of the working faces from the main air supply openings, the difficulty in providing blind workings with a calculated amount of air due to the lack of local ventilation fans of the required range. To ensure thermodynamic safety mine n.a. A.F.Zasyadko we accepted the development of a draft of a central cooling system with ground-based absorption refrigerating machines with a total capacity of 9 MW with the implementation of the three types of generation principle (generation of refrigeration, electrical and thermal energy). However, the long terms of design and construction and installation work necessitated the use of mobile air conditioners in blind development faces. The use of such air conditioners does not require significant capital expenditures, and the terms of their commissioning do not exceed several weeks. The use of a mobile air conditioner of the KPSh type with a cooling capacity of 130 kW made it possible to completely normalize the thermal working conditions at the bottom of the blind workings 2200 m long, carried out at a depth of 1220-1377 m at a temperature of host rocks 43.4-47.5 °С. It became possible due to the closest placement of the air conditioner to the face in combination with the use of a high-pressure local ventilation fan and ducts, which ensured the air flow produced by the calculated amount of air. The use of the air conditioner did not allow to fully normalize the thermal conditions along the entire length of the blind face but reduced the urgency of the problem of normalizing the thermal regime and ensured the commissioning of the clearing face.
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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 submitted2016-09-23
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Date accepted2016-11-18
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Date published2017-02-22
Principles of assessment and management approaches to innovation potential of coal industry enterprises
- Authors:
- A. V. Kozlov
- A. B. Teslya
- Sya Chzhan
This paper examines problems related to forming a complex of indicators to assess innovation potential of an industrial enterprise, on the example of coal industry enterprises, and an integral indicator of innovation potential, used for comparative analysis of the state of affairs in the industry. Analysis of different approaches to defining the term «innovation potential» for industrial enterprises has been carried out; resource-based, resultative, integrative and capacitive approaches have been highlighted, the latter one based on assessment of enterprise capacities. A conclusion has been made regarding advantages of integrative approach. Research has been made on the role of industry in the fuel and power sector of China and dynamics of industry and enterprise development in Shanxi province. Basing on suggested approach a system of assessment principles has been formulated, taking into account specific features of coal industry enterprises. Complex of indicators to assess innovation potential has been developed using expert evaluation method. An expertise procedure is proposed to assess competence of experts; results obtained from the expertise are presented. Proposed complex of indicators includes 23 parameters combined into three groups. Testing of proposed complex of indicators has been carried out on the example of coal industry in Shanxi province (China). Application of all stated principles has been proved in the process of indicator selection, assessment and formulation of recommendations for subsequent innovation potential management of coal industry enterprises. Proposed approach to forming a complex of indicators of innovation potential for industry enterprises permits to link together the logic of innovation potential definition, formation of the system of its principles, selection of the indicators complex for assessment and subsequent innovation potential management of the enterprise.
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Date submitted2015-10-05
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Date accepted2015-12-14
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Date published2016-08-22
Coal-peat compositions for co-combustion in local boilers
- Authors:
- A. V. Mikhailov
In article results of experiments on creation of coal and peat fuel compositions for burning in solid-fuel boilers are described. The main objective of research consisted in development of combination of coal dust and natural peat without binding additives. The role of peat consists that it increases efficiency of process of granulation, being natural binding. The method of granulation allows to utilize waste of the coal industry. Joint burning of two types of fuel – coal dust and peat reduces emission of sulfur dioxides. The cost of peat raw materials is lower, than artificial binding, applied to briquetting of coal dust. The composition of mix of coal dust and peat varied in the ratio 2:1, 1:1 and 1:2 in volume ratio at humidity of mix before extrusion of 65 %. In the course of preparatory operations of coal raw materials its crushing and sifting through sieve of 24 mesh (0,707 mm) was carried out. Procedure of hashing of samples of coal and peat was carried out before receiving homogeneous mixture. After hashing mix was located in piston press for receiving granules. Coal dust and wet peat pass semifixed extrusion on piston press with formation of cylindrical granules with a diameter of 16 mm. After extrusion of granule are dried to operational humidity of 25 %. Coal and peat fuel granules showed sufficient mechanical strength for transportation and power feed in solid-fuel boilers. Burning of coal and peat fuel granules in vitro at temperature of 800 °C does not lead to ashes agglomeration. The conducted preliminary researches showed prospects of utilization of coal waste by granulation method in mix with natural peat.
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Date submitted2015-08-02
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Date accepted2015-10-04
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Date published2016-04-22
Development of innovative technologies of dedusting in mining and advance coal mine faces
- Authors:
- G. I. Korshunov
- S. B. Romanchenko
The article describes the results of the implementation of investment projects in the field of complex dedusting implemented in major coal producing companies in Russia. Experimental study of the processes reduce the levels of dust in the workplace in the application of modern systems of irrigation and aspiration systems. The factors that determine the mass and composition of particulate airborne dust at various ways of dust suppression. The results of the analysis of the laser dispersed composition of particles removed from the air of the working area
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Date submitted2009-07-05
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Date accepted2009-09-25
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Date published2010-04-22
Active methods for control of geomechanical state of rock mass in coal deposit mining under complicated geological-and-mining conditions
- Authors:
- F. N. Voskoboev
- Yu. A. Semenov
- V. A. Zvezdkin
The paper presents the main technologies, characteristics, schematic diagrams and parameters of active methods for control of geomechanical state of technogenic rock mass, domain and technical-and-economical efficiency of their industrial application.
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Date submitted2009-07-24
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Date accepted2009-09-14
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Date published2010-04-22
Bulgarian coal industry in market economy
- Authors:
- Tzolo Voutov
Mining production in Bulgaria during the transitional period goes through four periods: 1990 – beginning of the period; 1995 – restructuring of mining production, formation of normative base; 2000 – end of transitional period; 2005-2008 – sustainable development of mining industry.
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Date submitted2008-11-19
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Date accepted2009-01-09
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Date published2009-12-11
Improvement of Russian coal industry development strategy
- Authors:
- A. N. Martemyanova
The work is dedicated to the problems of Russian energy safety by means of perfecting and optimization of the developing strategy of coal industry. The condition of Russian coal industry was analyzed and the main factors, that have an influence on it, were determined. The vision and the main aims of the developing strategy of coal industry and the recommendations of the coal industry state regulation mechanism perfection for the long period were defined in the article.
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Date submitted1953-07-24
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Date accepted1953-09-01
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Date published1954-12-04
Гидроэлектропривод насосных установок угольных шахт
- Authors:
- Unknown
В условиях угольных шахт регулирование центробежных насосов или вообще не применяется, или осуществляется задвижкой, что приводит к ухудшению к.п.д. насосной установки и, следовательно, к перерасходу энергии на водоотлив. Как показывают данные обследования ряда шахт, номинальный напор установленных насосов часто значительно превосходит напор, необходимый для преодоления статических и динамических сопротивлений при номинальной производительности насосной установки. Это, в свою очередь, во избежание недопустимой перегрузки приводного двигателя, приводит к необходимости продолжительной работы насосов с прикрытой задвижкой, т. е. со значительными непроизводительными потерями. Согласно данным А. И. Веселова, манометрический номинальный напор установленных насосов часто значительно превосходит напор, необходимый для преодоления геодезической высоты нагнетания, а производительность насосов оказывается выбранной с большим запасом. Касаясь, например, шахт Кизеловского района, А. И. Веселов пишет: «Крупнейшие водоотливные установки шахт им. В. И. Ленина и М. М. Володарского работают с излишним запасом напора, а отсюда, естественно, невысокий к. п. д. агрегата. Шахта им. В. И. Ленина на основных насосных станциях имеет излишнюю установленную производительность насосов, которая равна почти пятикратному нормальному притоку».