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Date submitted2023-03-16
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Date accepted2023-12-27
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Date published2024-04-25
Comprehensive assessment of deformation of rigid reinforcing system during convergence of mine shaft lining in unstable rocks
Operation of vertical mine shafts in complex mining and geological conditions is associated with a number of features. One of them is a radial displacement of the concrete shaft lining, caused by the influence of mining pressure on the stress-strain state of the mine workings. A rigid reinforcing system with shaft buntons fixed in the concrete lining thus experiences elastoplastic deformations, their value increases with time. It results in deviation of conductors from design parameters, weakening of bolt connections, worsening of dynamic properties of geotechnical system “vehicle – reinforcing”, increase of wear rate of reinforcing system elements, increase of risks for creating an emergency situation. The article offers a comprehensive assessment of displacements of characteristic points of the bunton system based on approximate engineering relations, numerical modeling of the deformation process of the bunton system and laser measurements of the convergence of the inner surface of the concrete shaft lining. The method was tested on the example of the reinforcing system of the skip-cage shaft of the potash mine. Displacement of the characteristic points of the reinforcing system is determined by the value of radial displacements of the surface of the concrete shaft lining. Evaluation of the radial displacements was made using monitoring measurements and profiling data. The results obtained make it possible to justify the need and timing of repair works. It is shown that the deterioration of the reinforcing system at different levels occurs at different rates, defined, among other things, by mechanical properties of the rock mass layers located at a given depth.
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Date submitted2023-04-11
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Date accepted2023-10-25
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Date published2024-07-04
Acid mine water treatment using neutralizer with adsorbent material
One of the biggest issues in the mining sector is due to acid mine drainage, especially in those abandoned mining operations and active ones that fail to adequately control the quality of their water discharge. The removal degree of copper, iron, lead, and zinc dissolved metals in acid mine drainage was investigated by applying different proportions of mixtures based on neutralizing reagent hydrated lime at 67 % calcium oxide (CaO), with adsorbent material – natural sodium bentonite, compared to the application of neutralizing reagent without mixing, commonly used in the neutralization of acid mining drainage. The obtained results show that the removal degree of dissolved metals in acid mine drainage when treated with a mixture of neutralizing reagent and adsorbent material in a certain proportion, reaches discharge quality, complying with the environmental standard (Maximum Permissible Limit), at a lower pH than when neutralizing material is applied without mixing, registering a net decrease in the consumption unit of neutralizing agent express on 1 kg/m3 of acid mine drainage. Furthermore, the sludge produced in the treatment with a mixture of the neutralizing reagent with adsorbent material has better characteristics than common sludge without bentonite, since it is more suitable for use as cover material, reducing the surface infiltration degree of water into the applied deposit.
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Date submitted2022-08-05
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Date accepted2022-11-17
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Date published2023-02-27
Feasibility study of using cogeneration plants at Kuzbass coal mines
The paper considers the problem of reducing greenhouse gas emissions in the process of coal mining during the coal mine methane utilization in power supply systems. An algorithm to form recommendations for the implementation of CMM generation is presented. A simulation model for one of the Kuzbass coal mines was developed in the PowerFactory software application. The simulation model considers the uneven nature of the power consumption of mining equipment. As a result of modeling, daily power consumption profiles and voltage levels in the coal mine power supply system were determined before and after the implementation of the proposed measures. Based on the results, the technical and economic effects was estimated, which consisted in reducing the direct and indirect carbon footprint, electricity and capacity fees. It has been established that the cost of carbon dioxide emission quotas significantly affects the investment attractiveness of cogeneration projects. Based on the results, recommendations are given to stimulate the development of small generation in coal mines.
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Date submitted2020-05-18
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Date accepted2020-06-16
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Date published2021-04-26
Traction asynchronous electric drive of mine electric locomotivesimulation model structure improvement
The article discusses the solution to the problem of underground railway transport slipping in dynamic modes, which occurs when there is a significant difference in the speeds of the driving and driven pairs of wheels. The state of the rail surfaces largely determines the coefficient of adhesion, therefore, using a mathematical model, the condition for the dependence of the magnitude of slipping and tractive effort is selected. For effective acceleration and deceleration of an electric locomotive, it is necessary to control the coefficient of adhesion at a certain level. A simulation model of rolling stock has been created, which for the first time takes into account a mechanical system with distributed parameters. In the structural diagram of the automatic control system of traction electric drives with frequency regulation, such factors as the volume of goods being moved, rolling friction, slope (rise) levels and the state of the rail track are taken into account. The simulation results show the features of the movement and stops of the freight train not only by the diagrams of speed and forces in the modes of acceleration-deceleration and uniform movement, but also the positions of the plungers and tractive forces on the couplings of the electric locomotive and all trolleys involved in the movement of goods. The practical application of the proposed method lies in the possibility of starting a heavily laden train from its place on the ascent section in conditions of insufficient adhesion coefficient with contaminated roads.
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Date submitted2019-01-11
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Date accepted2019-03-17
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Date published2019-06-25
Improving methods of frozen wall state prediction for mine shafts under construction using distributed temperature measurements in test wells
- Authors:
- L. Yu. Levin
- M. A. Semin
- O. S. Parshakov
Development of mineral deposits under complex geological and hydrogeological conditions is often associated with the need to utilize specific approaches to mine shaft construction. The most reliable and universally applicable method of shaft sinking is artificial rock freezing – creation of a frozen wall around the designed mine shaft. Protected by this artificial construction, further mining operations take place. Notably, mining operations are permitted only after a closed-loop frozen section of specified thickness is formed. Beside that, on-line monitoring over the state of frozen rock mass must be organized. The practice of mine construction under complex hydrogeological conditions by means of artificial freezing demonstrates that modern technologies of point-by-point and distributed temperature measurements in test wells do not detect actual frozen wall parameters. Neither do current theoretical models and calculation methods of rock mass thermal behavior under artificial freezing provide an adequate forecast of frozen wall characteristics, if the input data has poor accuracy. The study proposes a monitoring system, which combines test measurements and theoretical calculations of frozen wall parameters. This approach allows to compare experimentally obtained and theoretically calculated rock mass temperatures in test wells and to assess the difference. Basing on this temperature difference, parameters of the mathematical model get adjusted by stating an inverse Stefan problem, its regularization and subsequent numerical solution.
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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 submitted2018-12-25
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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 submitted2015-08-24
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Date accepted2015-10-16
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Date published2016-04-22
Ways to ensure reliability, safety and efficiency of the costruction and installation works when buildings and structures erecting by stabilizing process of the rocking cargo suspension
- Authors:
- L. A. Goldobina
- P. S. Orlov
Nondestructive optical methods for measuring of the «thick» films thickness of the order of 0,001-1,00 mm are analyzed. It is shown that using the laser beam radiation and modern optical and electronic schemes possible to decrease the time of single measurement to 1ms and less at the measuring frequency of 10-50 hz. The possibility of measuring thickness and spreading coefficient and evaporation kinetics of liquid films is demonstrated. A new computer method of the data processing aimed to determine the film thickness from the angle dependence of the laser beam reflection coefficient by the film is offered. The offered procedure and the experimental technique realizing it permits to decrease the thickness determination uncertainty to the order of ten.
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Date submitted2009-08-30
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Date accepted2009-10-02
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Date published2010-02-01
Estimation of stresses in system «massive – support – shaft drift» at dynamic loadings
- Authors:
- I. E. Dolgiy
- D. A. Kotikov
In article the question of dynamic influence on shaft drift a moving vessel is considered. Dependences of pressure in system «massive – support – shaft drift» from various in a direction and value of the loadings received by means of a method of final elements are resulted.
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Date submitted1953-07-21
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Date accepted1953-09-12
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Date published1954-12-04
К вопросу автоматизации рудничного подъема с асинхронным приводом при скипах с донной разгрузкой
- Authors:
- Unknown
Автоматизация подъема при скипах с донной разгрузкой в период замедления может быть осуществлена применением режима динамического торможения асинхронного подъемного двигателя. На рис. 1 расчетная диаграмма скорости в период замедления t 3 изображена пунктирной линией λр. В период разгрузки t 4 ' предположена постоянная скорость v 3 (линия рφ), которая в течение периода t 4 "падает до нуля по линии ϕѱ. Согласно диаграмме усилий асинхронной машины, изображенной на рис. 2, разгон подъемного двигателя в период пуска происходит по ломаной линии BCDEFGHIKLT,варьирующей около заданного (расчетного) значения усилия F 1 как около среднего значения между крайними пределами F 1 ' и F 1 ". По окончании периода пуска наступает период полного хода, в течение которого движущее усилие следует за всеми изменениями статического усилия. В предположении статически неуравновешенной системы подъема статическое усилие, а следовательно, и движущее усилие, развиваемое двигателем, работающим на естественной характеристике R 2 , пусть изменяется от значения F' s 2 в начале периода полного хода (точка N')до величины F" s 2 в конце этого периода (точка N). По окончании периода полного хода наступает период замедления t 3 , в течение которого предположен тормозной режим, осуществляемый в виде динамического торможения. Асинхронная машина с двигательного режима на характеристике R 2 при скорости v н переводится на динамический режим путем переключения статора с переменного тока на постоянный.
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Date submitted1953-07-25
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Date accepted1953-09-19
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Date published1954-12-04
Автоматизация шахтного грузового подъема с асинхронным приводом
- Authors:
- Unknown
Преимущества автоматического подъема, заключающиеся в увеличении производительности, повышении надежности работы и безопасности, а также освобождении труда высококвалифицированного машиниста и большое распространение в Советском Союзе подъемных установок с асинхронными двигателями делают проблему автоматизации подъема с асинхронным приводом весьма актуальной. Решение этой проблемы начато с 1932—1933 гг. Однако, несмотря на двадцатилетний срок, истекший с момента первых исследований по этому вопросу, до сих пор задача полностью не разрешена. Причина этого кроется в неблагоприятных механических свойствах асинхронного двигателя, затрудняющих автоматизацию подъема, а также в известной односторонности предлагавшихся до сих пор решений, основанных, как правило, на использовании в период замедления колодочных механических тормозов. Несмотря на многочисленные исследования, проведенные в основном В. Б. Уманским и В. С. Тулиным, создать хорошие регуляторы хода, воздействующие на механический тормоз подъемной машины, до сих пор не удалось. И если автоматизация пуска подъемной машины является на сегодня решенной, то вопрос управления подъемной машиной в период замедления требует еще теоретической и экспериментальной проработки. Анализ работы различных систем автоматизации подъема, основанный на сопоставлении механических характеристик различных тормозных устройств, позволяет критически оценить эти системы и наметить новые направления в решении задачи автоматизации грузового подъема с асинхронным приводом.
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Date submitted1953-07-28
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Date accepted1953-09-13
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Date published1954-12-04
О расчете подъемных шахтных канатов
- Authors:
- Unknown
Применяемый в настоящее время расчет подъемных шахтных канатов на прочность носит явно условный характер. В основание этого расчета положен так называемый статический коэффициент безопасности, представляющий отношение разрывающей нагрузки к нагрузке статической (вес каната и концевого груза). Само собой разумеется, что при таком способе расчета динамическая нагрузка совершенно не учитывается и действительное значение коэффициента безопасности (динамического) остается неизвестным. Естественно было ожидать, что указанное положение привело из понятных соображений осторожности к несколько преувеличенным значениям коэффициента безопасности, особенно для глубоких шахт, где вес каната играет существенную роль. В силу этого обстоятельства в американской практике значение упомянутого коэффициента устанавливается дифференцированно, в зависимости от глубины шахты и тем меньше, чем больше упомянутая глубина. По-видимому, условия работы каната в глубоких шахтах считаются более благоприятными в смысле величины напряжений. Следует все-таки указать, что последнее утверждение, хотя и носит на первый взгляд более или менее вероятный характер, до сих пор еще не является вполне обоснованным и, кроме того, имеет исходным пунктом оценку напряжений при нормальном режиме подъема.
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Date submitted1951-07-28
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Date accepted1951-09-07
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Date published1952-03-26
On the issue of dynamic braking as applied to a mine hoist with an asynchronous drive
- Authors:
- F. N. Shklyarskii
In practice, it may be necessary to lower people down a mine shaft at a reduced speed compared to the full speed of lifting the load. This makes it necessary to use braking operations, which in practice are often carried out using a mechanical brake. However, prolonged operation of a mechanical brake is accompanied by undesirable phenomena: excessive heating and wear of the brake pads, which necessitates the use of cooling devices and frequent replacement of worn pads with new ones. Electric braking systems are free from these drawbacks, of which in the case under consideration both counter-current (counter-switching) and dynamic braking can be used. To be able to implement the counter-current mode, the lifting unit must be equipped with a load rheostat, which, compared to an ordinary starting rheostat, must be designed for longer operation. In addition, this rheostat must have additional sections with a correspondingly increased resistance to be able to obtain small braking moments. The main disadvantage of counter-current braking is its uneconomical nature, due to the significant consumption of energy from the network. As is known, the power consumed in the counter-current mode from the network depends on the magnitude of the braking torque and synchronous speed and does not depend on the actual speed of descent. The energy consumed from the network is inversely related to the speed of descent.
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Date submitted1951-07-12
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Date accepted1951-09-03
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Date published1952-12-23
Electrical diagram of a lifting unit with an asynchronous drive
- Authors:
- F. N. Shklyarskii
For the proper functioning of the lifting unit, first of all, the correct operation of the main bearing lubrication must be ensured, which is carried out using two oil pumps, one of which is working and the other is a spare. The oil pumps are controlled using the oil pump switch. After the circuit of the coil 1RP is closed, its contact 1RP will close and thereby block the contact KK-0, which is open in the working positions of the command controller, ensuring the closure of the circuit of the coil 1RP until this circuit is broken by the limit switch ZVK, which is opened at the end of the lifting by the corresponding cage. When the circuit of the coil of the relay 1RP is closed, the contact of this relay 1RP, which is in the circuit of the coils of the reversing contactors B and I, will be closed. As a result, the circuit of the coils of the said reversing contactors will be closed at this point.
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Date submitted1948-07-13
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Date accepted1948-09-26
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Date published1949-11-04
Determination of tenion in hoisting ropes for low ascent and descent heights
- Authors:
- N. P. Neronov
The problem of determining stresses in hoisting ropes and the related question of longitudinal vibrations of elastic rods in terms of formulation and solution methods have a long history. The present work aims to continue the analytical development of the problem of determining stresses in hoisting ropes of variable length in order to supplement the theoretical material necessary for rational strength calculations of hoisting ropes. The calculation itself is carried out by combining the most unfavorable circumstances in terms of strength, taking into account both the normal lifting mode and its special cases. The methodology of such calculation requires additional research and is not included in our task.