ON THE DEVELOPMENT OF A GENERAL METHOD FOR FORECASTING THE DANGEROUS PROPERTIES OF COAL SEAMS

Author(s):  
Yevhen Rudniev ◽  
◽  
Vyacheslav Galchenko ◽  
Elvira Filatieva ◽  
Mykola Antoshchenko ◽  
...  

Purpose: to establish a quantitative effect on the dust-generating ability of mine layers of the degree of metamorphic transformations of fossil coals, mining-geological and mining conditions of mining operations and to provide proposals for the development of a general methodology for predicting other hazardous properties of mine layers. Methodology: research is based on the experience of using regulatory documents and analysis of the results of experimental and calculated data on dust formation of fine fractions for various observation conditions. Results: based on the analysis of statistical models of shallow and steeply dipping mine layers by groups of their dustiness, the effect of specific dust release, dust content in broken coal, moisture and thickness of the seams was established. Of all the possible factors that determine the specific dust release, the main ones are the design features of mining machines. The yield of small grades when tested by the falling weight method can serve as an indicator of the strength of coal. The use of such methods eliminates the errors caused by determining the degree of coal change during the transition from its actual destruction by a coal mining machine to the reference mode. The use of carbon content as one of the main indicators of the degree of metamorphism makes it possible to analyze the level of influence of both the sum of the remaining main components of the organic mass (hydrogen, nitrogen, sulfur, oxygen) and their separate influence. In order to bring the state of coal as close as possible to production conditions, it is necessary to additionally take into account moisture, mineral inclusions and their composition. The petrographic composition and some physical and mechanical properties are reliably characterized by the vitrinite reflectance index. The extreme limits of influence on dust formation of the design features of mass-produced combines differ by 43.4 times. The influence of metamorphic transformations at the extreme limits of the yield of the 1-0 mm class when testing coals in a pile driver is estimated by a difference of 5.6 times. The release of volatile substances taken as the main indicator of the degree of metamorphism in the normative base for the safe conduct of mining operations does not unambiguously characterize the gradation of mine layers according to their dustiness groups. The thickness of the mines being developed and the angles of occurrence do not determine their tendency to dust formation, but are the main criteria for choosing mining equipment for crushing coal in the massif. The general methodology for predicting the hazardous properties of coal mine layers, using the example of their dust-forming ability, should take into account the influence of factors of three blocks – metamorphic transformations, mining and geological and mining technical conditions. Scientific novelty: for the first time, a quantitative assessment of the effect on the dust-generating capacity of mine layers of a combination of factors of metamorphic transformation of fossil coals, mining-geological and mining-technical conditions of mining operations has been established. Practical value: the results obtained make it possible to substantiate and develop a general methodology for predicting the hazardous properties of mine layers, which will contribute to improving the regulatory framework for the safe conduct of mining operations.

2014 ◽  
Vol 59 (2) ◽  
pp. 509-516
Author(s):  
Andrzej Olajossy

Abstract Methane sorption capacity is of significance in the issues of coalbed methane (CBM) and depends on various parameters, including mainly, on rank of coal and the maceral content in coals. However, in some of the World coals basins the influences of those parameters on methane sorption capacity is various and sometimes complicated. Usually the rank of coal is expressed by its vitrinite reflectance Ro. Moreover, in coals for which there is a high correlation between vitrinite reflectance and volatile matter Vdaf the rank of coal may also be represented by Vdaf. The influence of the rank of coal on methane sorption capacity for Polish coals is not well understood, hence the examination in the presented paper was undertaken. For the purpose of analysis there were chosen fourteen samples of hard coal originating from the Upper Silesian Basin and Lower Silesian Basin. The scope of the sorption capacity is: 15-42 cm3/g and the scope of vitrinite reflectance: 0,6-2,2%. Majority of those coals were of low rank, high volatile matter (HV), some were of middle rank, middle volatile matter (MV) and among them there was a small number of high rank, low volatile matter (LV) coals. The analysis was conducted on the basis of available from the literature results of research of petrographic composition and methane sorption isotherms. Some of those samples were in the form (shape) of grains and others - as cut out plates of coal. The high pressure isotherms previously obtained in the cited studies were analyzed here for the purpose of establishing their sorption capacity on the basis of Langmuire equation. As a result of this paper, it turned out that for low rank, HV coals the Langmuire volume VL slightly decreases with the increase of rank, reaching its minimum for the middle rank (MV) coal and then increases with the rise of the rank (LV). From the graphic illustrations presented with respect to this relation follows the similarity to the Indian coals and partially to the Australian coals.


Author(s):  
A.F. Klebanov ◽  
M.V. Kadochnikov ◽  
V.V. Ulitin ◽  
D.N. Sizemov

The article addresses the issues of ensuring safe operation of mining equipment in surface mining. It describes the main factors and situations that pose a high risk to human life and health. The most dangerous incidents are shown to be related to limited visibility and blind spots for operators of mining equipment, which can result in collisions and personnel run over. The main technologies and specific solutions used to design collision avoidance systems are described and their general comparison is provided. A particular focus is placed on monitoring the health of employees at their workplace by means of portable personal devices that promptly inform the dispatcher of emergency situations. General technical requirements are formulated for designing of the system to prevent equipment collisions and personnel run over in surface mining operations. The paper emphasizes the importance of introducing a multifunctional safety system in surface mines in order to minimise the possibility of incidents and accidents throughout the entire production cycle.


Author(s):  
A.V. Zatonskiy ◽  
◽  
P.A. Yazev ◽  

The importance of production planning for improving the performance indicators of a mining enterprise is indicated. The possibility of simulation modeling using for this aim is shown. It is shown that the created model has a large number of stochastic parameters. It is investigated that there is a problem of research lack about the choice influence of the mining modeling results with different statistical distributions. It is known that with an increase in stochastic deviations from the initial parameters, the productivity of queuing systems decreases. Purpose of work is to study this influence with four statistical distributions of a random quantity (uniform, normal, negative bi-nomial and Poisson distribution) for individual operations and their combinations. In addition, it is necessary to determine how much a change in one particular parameter will affect the overall result of the modeling. Materials and methods. In the previously created simulation model, a stochastic delay is added to the time of individual operations. The addition of such a delay with different sta-tistical distributions and with the same mathematical expectation is investigated. The simulation re-sults are compared with each other, for each individual operation the absolute and relative devia-tion of the results is shown. Further, a similar simulation is performed when all the simultaneously selected parameters changing. Result. It is shown that the magnitude of the deviation significantly differs among all deviations. It is shown that for various single changes in operations, the largest and smal-lest deviations can be given by different statistical distributions. To study the joint change with all parameters, 3 modeling scenarios are implemented: all uniform distributions (this case is used now), the scenario with the smallest deviation and the scenario with the largest deviation. It is shown that switching to another scenario leads to a significant change in the simulation. Conclusion. It is con-cluded that the used significant influence of statistical distributions choice to the accuracy of model-ing the operation of the mining machine is shown, especially when they are taken into account to-gether. The results can be used to clarify the influence of individual factors in the simulation model and improve the planning of potash mining operations, for individual mining machines too.


Author(s):  
Ajit Kumar Pandey ◽  
Amit Kumar ◽  
Nitish Kumar

Hydraulic components play a significant role in the mining and construction equipment. It is responsible for smooth change in the output speed, torque, and power of the machine. The hydrostatic drive powered by a constant speed electric motor is widely used in the propel system of the mining equipment. Regulation of the displacements of the pump and the hydro-motor of the drive facilitates the control of the straight running and steering of the machines. In the present scenario, better efficiency and ease of control are the critical aspects to be considered in the design and selection of the hydraulic pump and motor used in underground mining operations. The bent axis hydro-motor is one such equipment that is an electro-hydraulic component that can work in an adverse working environment. The present study deals with the performance analysis of fixed displacement bent axis hydro-motor at different operating parameters such as different temperatures, sizes, viscosity at different loads, and drive speed. For analysis, the hydraulic drive consists of a variable displacement pump rotated by a constant speed electric motor and a fixed displacement hydro-motor. The regulation of the pump displacement controls the speed of the drive. Manually controlled hydrostatic drive propels the said machine against variable load demands. The present work investigates the performances of the hydro-motor used in the mining and construction machine through detailed modeling and experimentations. The steady-state performances are analyzed in terms of slip, torque losses and efficiency of the hydro-motor. The study finds the design guideline to operate the hydrostatic drive using such motors in a reasonable efficiency zone. The model is validated for various operating conditions of the equipment by comparing the predicted results with the test results. The outcome of the present work will be expedient for the preliminary design and assortment of similar hydraulic component used in the mobile, mining equipment.


Robotica ◽  
2001 ◽  
Vol 19 (5) ◽  
pp. 513-526 ◽  
Author(s):  
J. C. Ralston ◽  
D. W. Hainsworth ◽  
D. C. Reid ◽  
D. L. Anderson ◽  
R. J. McPhee

This paper presents some recent applications of sensing, guidance and telerobotic technology in the coal mining industry. Of special interest is the development of semi or fully autonomous systems to provide remote guidance and communications for coal mining equipment. We consider the use of radar and inertial based sensors in an attempt to solve the horizontal and lateral guidance problems associated with mining equipment automation. We also describe a novel teleoperated robot vehicle with unique communications capabilities, called the Numbat, which is used in underground mine safety and reconnaissance missions.


Dependability ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 18-23 ◽  
Author(s):  
I. V. Gadoiina ◽  
P. A. Pobegayio ◽  
D. Yu. Kritsky ◽  
L. Papić

The existence of humankind on Earth largely depends on the energy at its disposal. It is mostly generated by processing minerals extracted from the Earth’s crust by open-cut mining. The quality and low cost of extraction are largely defined by the dependability of employed machines and mechanisms, plants and process engineering solutions. Various types of excavators are the backbone of a mining machine fleet. Their parts that principally interact with the environment (rock) are components of implements, i.e. primarily the buckets and components of bucket(s). It must be noted that in the process of interaction with the environment (rock) the excavator implements and their components are exposed to so-called abrasive wear. Since abrasive wear of implement components (most frequently excavator bucket teeth) causes their recurrent replacement, this inevitably affects the performance of the excavator as a whole and those process flows it is part of. Occasional interruptions of operation and repairs reduce the availability factor, the most important complex indicator of equipment dependability. Given the above, the aim of this paper is to refine the previously known formula proposed more than thirty years ago in VNIISDM (Reysh A.K.) for evaluation of the rate of abrasive wear of excavator bucket teeth. For the first time, with a sufficient accuracy we examined the multitude of operating modes of mining equipment, i.e. operation of excavators in various conditions, e.g. on different soils. Additionally, we extended Reysh’s approach from single-bucket machines to continuous operation multi-bucket ones. For that purpose, the authors used a method of data integration from known sources, method of full-scale experiment under the operating conditions of a specific excavator and method of mathematical simulation (a form of the Monte Carlo method). All of that allowed revising the values of the parameters in the Reysh formula. The refined formula that we obtained can now be used for the dependability evaluation of machines operating under varying conditions, as well as for the purpose of appointing the time of preventive inspections.


2020 ◽  
Vol 244 ◽  
pp. 395-401
Author(s):  
Oleg Kazanin ◽  
Valeriy 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.


2020 ◽  
Vol 242 ◽  
pp. 228 ◽  
Author(s):  
Sergey IVANOV ◽  
Polina IVANOVA ◽  
Sergey KUVSHINKIN

The development prospects of the mining industry are closely related to the state and development of modern mining machinery and equipment that meet the technical and quality requirements of mining enterprises. Enterprises are focused on a quantitative assessment – the volume of mineral extraction, depending on the functioning efficiency of a promising series of mining machines, which include modern mining excavators. Downtime and unplanned shutdowns of mining excavators directly depend on the operating conditions of the mining machine, which has negative influence on the machine as a whole and its technical condition, which entails a decrease in the efficiency of using expensive mining equipment and economic losses of the mining enterprise. The rationale for external factors that affect the operating time and technical condition of mining excavators is given. For a more detailed assessment of the influence of external influences on the efficiency of operation of mining machines, the influencing factors are divided into two groups: ergatic, directly related to human participation, and factors of a natural-technogenic nature, where human participation is minimized. It was revealed that factors of a natural-technogenic nature have the greatest influence. An algorithm is proposed for a comprehensive assessment of the technical condition and forecasting of operating time both in nominal and in real operating conditions, taking into account factors of a natural and technogenic nature. It is proposed, based on the developed program for planning and evaluating the life of a mining excavator, to adjust the schedules for maintenance and repair (MOT and R) in order to minimize the number of unplanned downtime of a mining excavator and maintain it in good condition.


2020 ◽  
pp. 74-79
Author(s):  
V. P. Zubov ◽  
◽  
D. G. Sokol ◽  

Currently mines of Belaruskali actively expand production capacities in the conditions of great depth of productive strata and high concentration of mining operations. High power loading of mining equipment in combination with complicated geotechnical conditions are the major causes of increased air temperatures in longwalls. In view of the intended social and technological improvement, one of the current tasks of the top priority is normalization of temperature conditions in longwalls pursuant to the effective standards. The data required for the set task solution were obtained during underground investigation of geotechnical situations which have influence on temperature of intake air currents in longwalls. This article presents the research findings on the formation of temperature conditions in longwall mining. At the great mining depths (500–600 m and more), the temperature of intake air currents exceeds the maximal allowable values. It is expedient to change to the specially designed pillarless mining flow charts capable to ensure independent ventilation of longwall and power train, and to enable heat transfer between intake air flow and rocks in mined-out areas.


Author(s):  
VELIKANOV Vladimir Semenovich ◽  

Relevance of the work is due to the need for further modernization of the economy of the Russian Federation, which involves solving both basic theoretical and applied problems of the domestic mining industry. This circumstance largely determines not only the state of the state’s production resources, but also its scientific and technical potential. The global trend in the development of mining operations in the world is mainly determined by open pit mining of raw material resources. Open pit mining is characterized by an increase in the volume of processed rock mass, improved production processes through the use of advanced technologies, which entails the use of high-capacity mining machines. The main problems of open-cut mining are the following: complex mining and geological and mining-technical conditions; depletion of the mineral resource base; and constantly changing environmental conditions. All this leads to an increase in the cost of mining and a decrease in the competitiveness of the products of mining companies. Objective of the work. To establish the need to modernize traditional technologies in open pit mining with the possibility of integrating the main ideas of Industry 4.0. Research methodology. When solving the set tasks a complex approach was used, including: scientific analysis and synthesis of previously published research, analytical studies, laboratory experiment and observations of the work of open-pit excavators in real operating conditions. The methods of mathematical statistics include system analysis and modeling with the use of information technologies form the methodological basis of the research. Results. This paper deals with the issues of modelling the cab of a quarry crawler excavator to meet the technical requirements for the excavator cab in protecting against tipping and rock impacts. Model setup and analysis of simulation results after loading are performed using Autodesk Inventor software. An optimal finite-element model of an excavator operator’s cabin has been developed to assess the effectiveness of its structural protection. Conclusions. Implementing the core ideas of Industry 4.0 is a complex scientific and technical challenge. Its solution is connected with significant economic costs, including modernization of mining equipment, infrastructure, as well as changes in the technology of open-cast mining. The implementation of complex automated control systems and practical application of the latest information and geoinformation technologies will unambiguously give high estimated figures and have high applied potential, and ultimately ensure safety of open pit mining, increase of efficiency and productivity, possibility of mining in regions with complex mining and geological and mining-technical conditions.


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