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Date submitted2023-03-16
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Date accepted2023-06-20
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Date published2023-07-19
Evaluation of the influence of the hydraulic fluid temperature on power loss of the mining hydraulic excavator
In the steady state of operation, the temperature of a mining excavator hydraulic fluid is determined by the ambient temperature, hydraulic system design, and power losses. The amount of the hydraulic system power loss depends on the hydraulic fluid physical and thermodynamic properties and the degree of wear of the mining excavator hydraulic system working elements. The main causes of power losses are pressure losses in pipelines, valves and fittings, and leaks in pumps and hydraulic motors. With an increase in the temperature of hydraulic fluid, its viscosity decreases, which leads, on the one hand, to a decrease in power losses due to pressure losses in pipelines, valves and fittings, and, on the other hand, to an increase in volumetric leaks and associated power losses. To numerically determine the level of power losses occurring in the hydraulic system on an example of the Komatsu PC750-7 mining excavator when using Shell Tellus S2 V 22, 32, 46, 68 hydraulic oils with the corresponding kinematic viscosity of 22, 32, 46, 68 cSt at 40 °C, the developed calculation technique and software algorithm in the MatLab Simulink environment was used. The power loss coefficient, obtained by comparing power losses at the optimum temperature for a given hydraulic system in the conditions under consideration with the actual ones is proposed. The use of the coefficient will make it possible to reasonably select hydraulic fluids and set the values of the main pumps limit state and other hydraulic system elements, and evaluate the actual energy efficiency of the mining hydraulic excavator. Calculations have shown that the implementation of measures that ensure operation in the interval with a deviation of 10 % from the optimal temperature value for these conditions makes it possible to reduce energy losses from 3 to 12 %.
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Date submitted2022-09-30
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Date accepted2023-02-13
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Date published2024-02-29
Improving the efficiency of oil vapor recovery units in the commodity transport operations at oil terminals
- Authors:
- Vladimir V. Pshenin
- Gulnur S. Zakirova
In this paper the problem of losses from evaporation of light fractions of hydrocarbons during loading operations of tanker fleets vessels is considered. It was found that there is no unified approach to modeling the system “tanker – gas phase pipeline – vapor recovery units” in open sources. The absence of a generally recognized model makes it impossible to scientifically justify the application of instruments to reducing losses and the development of corresponding measures. In work it is showed that the dynamics of growth of pressure in the inner tanker capacity is described by a differential equation, considering for non-stationary essence of the process. This equation is converted to a non-dimensional form and investigated in relation to the similarity criteria of this system. This research has allowed to establish unambiguously the general character of pressure changes in the inner tanker capacity, and to predict the peak values of its growth at the initial stage of the loading operation. The obtained equations were tested on real tanker loading data and showed satisfactory convergence with the experimental data. At different stages of the loading opera-tion the component composition of vapor changes, which is shown by chromatographic analysis of the gas mixture. With the availability of a model of hydrocarbon vapor displacement from the inner of tanker, it is possible to propose measures to minimize the negative impact on the environment and return valuable vapors of the product to the technological chain of transportation.
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Date submitted2022-11-04
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Date accepted2023-03-03
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Date published2023-04-25
Efficiency of acid sulphate soils reclamation in coal mining areas
During the development of coal deposits, acid mine waters flowing to the surface cause the formation of acid sulphate soils. We study the effectiveness of soil reclamation by agrochemical and geochemical methods at the site of acid mine water discharge in the Kizel Coal Basin, carried out in 2005 using alkaline waste from soda production and activated sludge. A technosol with a stable phytocenosis was detected on the reclaimed site, and soddy-podzolic soil buried under the technogenic soil layer with no vegetation on the non-reclaimed site. The buried soddy-podzolic soil retains a strong acid рН concentration Н 2 О = 3. A high content of organic matter (8-1.5 %) is caused by carbonaceous particles; the presence of sulphide minerals reaches a depth of 40 cm. Technosol has a slightly acid pH reaction H 2 O = 5.5, the content of organic matter due to the use of activated sludge is 19-65 %, the presence of sulphide minerals reaches a depth of 20-40 cm. The total iron content in the upper layers of the technosol did not change (190-200 g/kg), the excess over the background reaches 15 times. There is no contamination with heavy metals and trace elements, single elevated concentrations of Li, Se, B and V are found.
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Date submitted2022-04-05
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Date accepted2022-07-21
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Date published2022-11-10
Development of resource-saving technology for excavation of flat-lying coal seams with tight roof rocks (on the example of the Quang Ninh coal basin mines)
- Authors:
- Vladimir P. Zubov
- Le Quang Phuc
It is shown that the creation of the variants of resource-saving systems for the development of long-column mining is one of the main directions for improving the technological schemes for mining operations in the mines of the Kuang Nin coal basin. They provide a reduction in coal losses in the inter-column pillars and the cost of maintaining preliminary workings fixed with anchorage. The implementation of these directions is difficult (and in some cases practically impossible) when tight rocks are lying over the coal seam, prone to significant hovering in the developed space. In the Quang Ninh basin, 9-10 % of the workings are anchored, the operational losses of coal reach 30 % or more; up to 50 % of the workings are re-anchored annually. It is concluded that the real conditions for reducing coal losses and the effective use of anchor support as the main support of reusable preliminary workings are created when implementing the idea put forward at the St. Petersburg Mining University: leaving the coal pillar of increased width between the reused mine working and the developed space and its subsequent development on the same line with the stoping face simultaneously with the reclamation of the reused mine working.
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Date submitted2021-02-28
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Date accepted2021-11-30
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Date published2021-12-27
Substantiation of analytical dependences for hydraulic calculation of high-viscosity oil transportation
- Authors:
- Alexander K. Nikolaev
- Natalia А. Zaripova
One of the development priorities in oil and gas industry is to maintain gas and oil pipeline networks and develop pipeline-connected gas and oil fields of the Arctic zone of the Russian Federation, a promising region the resource potential of which will not only meet a significant portion of internal and external demand for various types of raw materials and primary energy carriers, but will also bring great economic benefits to subsoil users and the state. The mineral and raw material centers of the Nadym-Purskiy and Pur-Tazovskskiy oil and gas bearing areas are among the most attractive regions of the Arctic zone. It is necessary to develop a scientifically substantiated approach to improve the methods of oil transportation from the field to the existing pipelines. As it is known, the task of increasing the efficiency of pipeline transportation of high-viscosity oil is inseparably connected with solving problems in the field of thermal and hydraulic calculation of pipeline system. The article presents the substantiation of dependencies for hydraulic calculation of pipelines transporting high-viscosity oil exhibiting complex rheological properties. Based on the laws of hydraulics for non-Newtonian fluids, the formulas for calculating head losses for fluids obeying Ostwald's law are proposed, their relationship to the classical equations of hydraulics is shown. The theoretical substantiation of looping installation for increasing the efficiency of pipeline transportation of high-viscosity oil taking into account the received dependences for power fluid is considered.
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Date submitted2021-06-15
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Date accepted2021-08-27
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Date published2021-10-21
Prospects for the use of modern technological solutions in the flat-lying coal seams development, taking into account the danger of the formation of the places of its spontaneous combustion
- Authors:
- Vladimir P. Zubov
- Dmitrii D. Golubev
Spontaneous combustion of coal remains an important problem for coal mines, which can lead to an explosion of methane and coal dust. Accidents associated with spontaneous combustion of coal can cause significant economic losses to coal mining companies, as well as entail social damage – injuries and loss of life. Accidents are known at the Kuzbass mines, which occurred as a result of negligent attitude to the danger of spontaneous combustion of coal, the victims of which were dozens of people. The analysis of emergency situations associated with spontaneous combustion of coal shows that the existing wide range of means of preventing endogenous fires does not provide complete safety when working out coal seams prone to spontaneous combustion, therefore, spontaneous combustion places continue to occur in mines. The consequences that may arise as a result of a methane explosion initiated by a self-ignition place indicate the need to improve the used technologies. The purpose of the work is to determine the impact of modern technological solutions used in functioning mines during underground mining of flat-lying coal seams prone to spontaneous combustion, and to develop new solutions that reduce endogenous fire hazard. Conclusions on the influence of leaving coal pillars in the developed space, isolated air removal from the stoping face through the developed space, the length of the stoping face and the excavation pillar, and other factors on the danger of the formation of spontaneous combustion places are presented. Conclusions about the possibility of using modern technological solutions in future are also drawn.
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Date submitted2020-02-19
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Date accepted2020-04-17
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Date published2020-10-08
Decrease in coal losses during mining of contiguous seams in the near-bottom part at Vorkuta deposit
- Authors:
- Oleg I. Kazanin
- Valeriy V. Yaroshenko
The problem of formation of extended zones with high rock pressure (HRP) from safety pillars at the boundaries of extraction pillars formed due to the mine layout of complex geometry is considered at the example of JSC Vorkutaugol mines. A detailed analysis of the remaining reserves of the near-bottom part of the deposit was carried out to estimate losses and the impact of HRP zones from the Chetvertyi protective seam to mining operations on the Troinoi upper seam along with the possibilities for the reduction of sizes of HRP zones at the account of expanding the underworked space. Due to research on the near-bottom part of the Vorkuta deposit, within the framework of the accepted layout, a zone at the Komsomolskaya mine and two zones at the Zapolyarnaya-2 mine were singled out, at which losses at the boundaries of the extraction pillars amount up to 13-22 % of the total resources of the mine field. The high volume of losses in these pillars indicates the relevance of research on the priority extraction impact of protective seams on the efficiency and safety of mining operations in the working area of underworked and HRP zones. Based on the analysis of foreign and Russian experience in the pillar cleaning-up at the boundaries of working areas and the methodical guidelines and instructions, a technological scheme was developed that allows increasing the coal mining recovery factor in the near-bottom part of the Vorkuta deposit from 0.75 to 0.9 without fundamental changing of the ventilation and transport networks and also without purchasing any additional mining equipment. The conducted economic calculations confirmed the effectiveness of implementing the new technological scheme for cleaning-up reserves at the boundaries of extraction districts. The economic effect is from 0.079 to1.381 billion rubles of additional profit from coaxial extraction pillars, depending on the mining and geological conditions and the size of the pillars.
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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 submitted2019-03-21
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Date accepted2019-04-30
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Date published2019-08-23
Actual and Forecast Impact Assessment of Earthquakes on the Global Economic System
- Authors:
- T. P. Skufina
- S. V. Baranov
- V. P. Samarina
Problem of strong earthquakes impact on the global economic system is considered. Geoscientists suggest that increase in Earth's seismicity is highly unlikely, but experts in economic geography say that existing facts indicate increase in seismic risk for economic systems. Using the example of an earthquake in the Tahoku region (Japan, 2011), a comprehensive assessment of economic consequences of a strong earthquake is presented as a part of analysis of three blocks of statistical information: 1) macroeconomic indicators of Japan; 2) stock market indicators; 3) industry indicators of the global economy. Results of the assessment pointed to a new feature of strong earthquakes effects in economically developed regions of the world: globalization processes are spreading regional effects of large earthquakes throughout the world economic system. To understand the magnitude of strong earthquakes problem, estimate of world economy loss from a probable earthquake near the United States, similar to Tahoku, is given. It was established that economic losses would be 2.6 times greater: a drop in the global S&P Global 1200 index would be about 15 %. The farther in time this probable earthquake protects from the Tahoku earthquake, the more globalization will increase losses.
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Date submitted2018-05-07
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Date accepted2018-07-06
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Date published2018-10-24
Hydraulic transportation of thickened tailings of iron ore processing at Kachkanarsky GOK based on results of laboratory and pilot tests of hydrotransport system
- Authors:
- V. I. Aleksandrov
- M. A. Vasileva
The object of study is the system of hydrotransport of iron ore processing tailings at JSC «EVRAZ Kachkanarsky GOK». The aim of the work was to determine the parameters of the hydraulic transport of tailings of the iron ore enrichment at weight concentrations of the solid phase from 30 to 70 % and to develop recommendations for the industrial operation of hydraulic transport systems of highly concentrated slurries of the Tailing Facilities of the Kachkanarsky GOK. Laboratory studies of the parameters of hydrotransport of thickened tail pulps were carried out with the development of a calculation method; pilot tests of the hydrotransport system under the conditions of the Tailing Facilities of the Kachkanarsky GOK. It has been established that using polyurethane coatings on the inner surface of the slurry lines significantly (1.75 times) decrease the specific pressure loss on the hydrotransport of thickened fluids. This allows to significantly increase the range of transportation for placing tailings in the distant parts of the storage zone. The introduction of research results is in the project of reconstruction and development of the tailing facility of the TF of the Kachkanarsky GOK for the period 2018-2020. It is proposed to use the results of work in the project of reconstruction of the hydraulic transport system at the TF of the Kachkanarsky GOK by switching to the hydraulic transport of slurries thickened to weight concentrations of 35-40 % in the slurry pipes with an internal polyurethane coating, which will ensure energy saving in the hydraulic transport process.
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Date submitted2016-09-05
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Date accepted2016-10-27
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Date published2017-02-22
Impact of the shape of geological contact on mining losses in the process of near-contact zone development
- Authors:
- G. S. Kurchin
- S. A. Vokhmin
- A. A. Kytmanov
In Russia development of mineral resources is carried out on a truly grand scale, and mining industry is in its essence a basic sector, supporting and facilitating the development of national economy. It predetermines the need of safe and responsible attitude towards riches of our subsoil – mineral resources. With this in mind, one of the key requirements to extraction technologies is minimization of mining losses and ore dilution. The biggest ore losses in the mining block take place in the process of development of contact areas between the ore body and surrounding rocks, due to differences between development pattern and surface of geological contact. Complexity of the contact between ore and surrounding rocks is traditionally characterized by so called «stochastic contact zone». Technological difficulty of extracting ore from the ore – wallrock contact is determined by volatility of geometric parameters in «stochastic contact zone» in the plane of geological contact. Current paper focuses on the issues of standard-setting for mining losses and ore dilution in the process of near-contact zone development. A method is suggested to estimate standard values of losses and ore dilution in stochastic zones. Authors have developed an algorithm of defining the shape of the contact. In the stochastic zone the contact can have a rectangular, sinusoidal, serrate and straight-line shapes. Research has established a relation between the contact shape and amounts of mining losses and ore dilution, formulas to calculate standard values are presented. Using suggested method, standard values for contact ore losses can be obtained in a quicker and more reliable way.
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Date submitted2015-12-22
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Date accepted2016-02-13
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Date published2016-12-23
Risk of injuries among coal mine workers and its hysteresis
- Authors:
- Yu. Parkhanski
The paper gives an overview of employment in coal mining, levels of extraction and injuries among the coal mine operators in Poland over a span of time from 1954 through to 2010. The injury indicators, such as the incidence rate, severity and the generalized loss index, have been assessed for a period of coal mining sector restructuring from 1993 to 2010. Diverging trends have been revealed, resulting in a need to extend the time span of the analysis. Analysis of records from 1954 to 2010 has shown a multiple cyclicity of trends of change in the values used to derive coefficients. The definition of the Injury Risk has been justified, along with a new way for its representation and its interpretation as a new method with account of the previous studies. Based on this method the injuries at the coal mines of Poland during a period of their restructuring have been investigated with analyzed database expansion to include records from 1954 to 2010.As a result a new dependency, namely the injury risk hysteresis, has been identified.
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Date submitted2015-12-01
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Date accepted2016-02-29
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Date published2016-12-23
Simulation of diesel engine energy conversion processes
- Authors:
- A. S. Afanasev
- A. A. Tretyakov
In order to keep diesel engines in good working order the troubleshooting methods shall be improved. For their further improvement by parameters of associated processes a need has arisen to develop a diesel engine troubleshooting method based on time parameters of operating cycle. For such method to be developed a computational experiment involving simulation of diesel engine energy conversion processes has been carried out. The simulation was based on the basic mathematical model of reciprocating internal combustion engines, representing a closed system of equations and relationships. The said model has been supplemented with the engine torque dynamics taking into account the current values of in-cylinder processes with different amounts of fuel injected, including zero feed. The torque values obtained by the in-cylinder pressure conversion does not account for mechanical losses, which is why the base simulation program has been supplemented with calculations for the friction and pumping forces. In order to determine the indicator diagram of idle cylinder a transition to zero fuel feed mode and exclusion of the combustion process from calculation have been provisioned.
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Date submitted2014-12-20
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Date accepted2015-02-13
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Date published2015-12-25
Design procedure of pressure losses for hydrotransport of the high concetration pulps
- Authors:
- V. I. Aleksandrov
- Pavel Vlasak
In the paper it is shown that application of standard design methods for hydrotransport used for slurry with small concentration of a solid phase and for hydrotransport of high concentration slurry leads to considerable divergences between practical values of pressure losses which are received as a result of calculation. A major factor, which defines errors of calculation of hydrotransport of slurry with high concentration of a solid phase by means of standard techniques, is that these techniques do not consider rheological characteristics and parameters substantially influencing the amount of spe-cific pressure losses. The offered model of a pulp movement and technique developed on the basis of this model allow to define hydrotransport parameters with a margin error no more than 0,1.
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Date submitted2013-07-17
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Date accepted2013-09-07
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Date published2014-03-17
Increasing efficiency and mine resource development on the Prokopevsk-Kisilevsky deposit
The security issues of the deep mining of Prokopevsk-Kisilevsky deposit the Kuzbass are considered. The analysis of the existing technologies and systems development are executed. The recommendations to improvement of the technical and economic parameters, reducing accidents and injuries of the working off inventories powerful coal steeply inclined seams and steep coal seams were given.
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Date submitted2013-07-14
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Date accepted2013-09-07
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Date published2014-03-17
Open cast geological conditions analysis and the mining units formation in ore losses and dilution determining
- Authors:
- S. I. Fomin
- P. B. Kava
- M. A. Marinin
The opencast geological conditions analysis and the mining units formation in ore losses and dilution determining is given in dynamic type. The optimum height of immixed rocks triangle on minimum economic damage from losses and dilution criterion is determined. Minimum damage of an enterprise from losses and dilution of one ton of ore that provides minimum producing cost of ore mining is accepted as a criterion of optimum correlation of technological standards of rate of contact areas and standards of losses and dilution of ore.
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Date submitted2013-07-28
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Date accepted2013-09-08
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Date published2014-03-17
Endogenous fire hazard Kuzbass mines
- Authors:
- A. A. Sidorenko
The analysis of a current state of a problem of emergence of endogenous fires is made at working off of coal layers in mines. Influence of mining-and-geological conditions on efficiency and safety of working off of the layers inclined to selfignition is considered. Need of an integrated approach to a solution of the problem of endogenous fires is shown at working off of stocks in difficult mining-and-geological conditions.
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Date submitted2009-10-05
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Date accepted2009-12-05
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Date published2010-09-22
Control of rock mass state in mining the sections at mines оf the Vorkutaugol JST: up-to-date practice
- Authors:
- O. V. Yamenko
- I. E. Plisko
The article briefly outlines the methods and measures used at mines of the Vorkutaugol JSC to control the stress strain state of rock massif. These measures help to increase face load and to ensure mine safety.
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Date submitted2009-10-12
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Date accepted2009-12-19
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Date published2010-09-22
Preventive measures of gas-dynamic phenomena in the workings drivage on the rockburst- outburst-hazardous seams under extremely complicated geological and mining conditions
- Authors:
- V. P. Kostromin
A complex of measures preventing the manifestation of rockbursts and sudden outbursts of coal and gas has been developed. Criteria of forecasting, an assessment of efficiency of the preventive measures are suggested, as well as the necessary technical facilities and technologies.
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Date submitted2009-08-04
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Date accepted2009-10-26
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Date published2010-02-01
The strategic analysis of resource conservation technology capabilities for the underground gas storage facilities
- Authors:
- G. S. Elizarova
General estimate the appeal of the resource conservation technologies in combination with growth prospectives, profitability and possible instability in underground gas storage facilities is received.
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Date submitted1950-08-24
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Date accepted1950-10-14
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Date published1951-08-08
Materials for the qualitative characteristics of coal in the Nelidovsky district
- Authors:
- I. G. Kuprov
The properties of coal in the Nelidovsky district are generally characterized in exploration reports based on the results of petrographic and chemical analyses of core samples. The exploration materials indicate that humus coal varieties (duren, clarene-duren and claren) are predominantly common in the Nelidovsky district, while humus-sapropel varieties are less common. The analyses provided in the same materials show a clearly expressed inconstancy of the chemical composition of coal. Thus, its technical composition is characterized by the following data: hygroscopic humidity from 2.85 to 33.74%; ash content of dry coal from 28.41 to 46.63%; volatile yield on a dry basis from 21.21 to 33.03%; total sulfur from 1.16 to 2.30%. The elemental composition of the organic matter is as follows: carbon from 68.05 dog 75.42%; hydrogen from 4.42 to 5.70%; nitrogen from 0.33 to 1.30% and oxygen in total with sulfur from 20.93 to 26.33%. The yield of dry distillation products: moisture from 3.90 to 15.60%; resins from 3.50 to 9.00%; semi-coke from 63.26 to 83.60%; gas and losses from 6.80 to 12.20%. The calorific value of dry coal fluctuates within 3470-5269 calories. Obviously, the main reason for the inconsistency of chemical properties is the petrographic heterogeneity of coal. Therefore, to resolve the issue of the most rational use of coal in this newly developed region, it is important to know what role each of the petrographic types plays in the formation of the layers and their properties.