Field Of Coal Mining Research Articles

Mine subsidence prediction using gene expression programming based on multivariable symbolic regression

Accurate prediction of surface subsidence becomes a significant challenge for active industrial companies in coal mining fields due to the importance of the economic impacts of longwall mining-induced subsidence. This article explores a new variant of genetic programming, namely gene expression programming (GEP). The GEP-based method is utilized to present a new mathematical formula for subsidence prediction in longwall coal mining. The derived model includes both geometrical and geological variables. The data set consists of field measurements obtained through 37 longwall panels of Ulan coal mine, NSW, Australia. The GEP-based model concluded satisfactory subsidence prediction outcomes compared to other empirical methods such as NCB, DMR, ACARP, and IPM. The predictive ability of the GEP-based models, which captures the complex nonlinear effects of the critical factors on the magnitude of subsidence, resulted in a statistically significant improvement in predictive capacity compared to the aforementioned empirical methods. The sensitivity analysis results indicated that Panel width and cover thickness with 31% and 23% were the most influential parameters in the proposed model. Also, the extracted seam thickness, thick layer location, and thick layer thickness had 19%, 16%, and 11% impact on the GEP proposed model, respectively.

Environmental efficiency of gas purification and ash collection in Russian mining and metallurgical industry

The problem of reducing emissions of sulfur dioxide from the flue gases of coal-fired TPPs is highly relevant for domestic energy in connection with the annual increase in coal production. This article analyzes statistical data in the field of coal mining, describes the current state in the field of gas purification and ash collection in the mining and metallurgical industry of the Russian Federation. To regulate pollutant emissions by stationary sources in Russia, a system of maximum permissible and temporarily agreed emissions (MPE and ENV) was introduced. The country takes part in international programs aimed at protecting the environment from the harmful effects of human activity. Despite the general dynamics of reducing air pollution in the Russian Federation, emissions from mining and metallurgical enterprises only increase. This is due to deficiencies in the technical condition and operation of dust and gas cleaning equipment at electric power enterprises. The main ones are the moral and physical deterioration of the equipment fleet, the need for reconstruction and modernization of devices. The average degree of flue gas cleaning from ash at Russian TPPs is 95.5 %, which is noticeably less than abroad. Efficiency of the gas treatment plants used does not meet modern environmental requirements. The flue gases at our TPPs are not cleaned from sulfur and nitrogen oxides; there are practically no devices for continuous monitoring of TPP emissions. The article provides the rationale for the transition of enterprises to the best available technologies (BAT) in the field of gas purification. The use of a gas conditioning system allows 30 – 40 % reduction in the amount of funds spent on the construction of electrostatic filters. In recent years, in connection with the advent of new technologies for burning coal, filters for the purification of hot gases made of ceramic materials have been created. We have analyzed the state of gas purification and ash collection in the mining and metallurgical industry of the Russian Federation and its impact on the atmosphere. An assessment of the current state of gas purification equipment at the enterprises was carried out.

Mechanical strength of slag crushed stone generated at coal-fired thermal power plants

Introduction. Production waste is used in the construction industry worldwide as it helps to cover a considerable portion of the industry’s demand for building materials. Coarse-grained slag deposits (slag crushed stone and sand), formed in the slag washout zone, have more potential for application than other ash and slag mixtures (coarse ASM), but they need more research. Mechanical properties of the slag crushed stone (coarse-grained ASM), formed in the course of coal combustion at Kansk-Achinsk, Kuznetsk coal deposits (in boilers equipped with liquid and dry slag removal facilities) and the application of the slag crushed stone in roadbuilding are considered.
 Materials and methods. In the course of the research, the crushability and the deformation modulus of particular fractions of slag crushed stone samples (in dry and water-saturated conditions) taken from the dumps of Novosibirsk TPP-3 (that consumes the coal of the Kansk-Achinsk coal mining field) and from Novosibirsk TPP-2 and Seversk TPP (that consume the coal of the Kuznetsk coal mining field) were identified. To assess the factors influencing the mechanical strength of the slag crushed stone, ignition losses, the content of flaky and acicular particles, dust and clay particles and clay lumps was made.
 Results. The difference in the mechanical strength of samples having different genesis was identified. The graphs obtained in the course of testing were assessed and deformability characteristics were calculated (for materials having different fineness values). The factors influencing the mechanical strength of slag crushed stone were determined. Dependencies between deformation parameters and crushability of the slag crushed stone were obtained.
 Conclusions. Some mechanical and physical parameters of the slag crushed stone were identified; they were applied to outline potential areas of the slag crushed stone application in road building. The mathematical relationship needed to project the deformation modulus of the slag crushed stone was identified. This relationship will be used to design structures to be made of this material.

HUKUM SEBAGAI INSTRUMEN KEBIJAKAN PUBLIK DALAM IZIN USAHA PERTAMBANGAN BATUBARA


 
 
 
 Indonesia is known as an international coal supplier, as in Borneo. The March 2007 abare report (Australian bureau research for agriculture and economic resource) has placed Indonesia as the world's largest coal supplier (about 25%) in the world, followed by Australia, South Africa, China, the Russian, Colombian, and United States. Massive uncontrolled coal deployment, one day it's going to cause big trouble. On the negative side, this actually encourages both national and foreign private companies to achieve even greater coal extinctions. Therefore, governments should actually be working on the redefinition and reorientation of the mining exploitation to be truly beneficial to the people.
 There are two problems that appear: 1) How is the law as a public policy instrument in coal mining business license?, 2) How does the institutional public policy model in mining permissions? To answer the issue is used descriptive research method analysis so that it is concluded that: Mining Problems in Indonesia lies in the exploitation of coal mining that is so great to overlook the interests of local communities and the environment. The role of law as a public policy instrument can be poured through coal mining permissions. This permission policy uses an institutional public policy model where the government is legitimizing licensing. The legitimacy has implications in the sanctions of any violations in the field of coal mining both in the form of criminal sanctions and administrative sanctions. This policy is also universal.
 
 
 

Attitude Optimization Control of Unmanned Helicopter in Coal Mine Using Membrane Computing

Unmanned helicopter for mission inspection has good application value in intelligent coal mining, and attitude control is important. In this paper, membrane computing is introduced to realize attitude optimization control of an unmanned helicopter. First, we give the application scenarios of unmanned helicopters in coal mines. Secondly, we establish a dynamic model of an unmanned helicopter with environmental participation, and the attitude model of the helicopter is deduced based on this model. Further, the cellular membrane system suitable for the attitude model of an unmanned helicopter under the control parameters of environment mapping is constructed, and the cellular membrane controller based on the characteristics and operation rules of the membrane system is designed. The robust performance of the controller is proved theoretically, and by the semiphysical experiments, the performance of trajectory tracking is almost consistent and attitude angle control is less than±1°, in the range of±2°by wind disturbance. Compared with the linear feedback controller in the same experimental environment, the performance of the membrane controller is improved by nearly 0.4026 on average. It shows that the cellular membrane controller constructed has good effectiveness and robustness. This will provide a good application value for membrane computing in the field of accurate coal mining.

Development and creation of an innovative scientific and educational cluster for the integrated use of coal and its products

The article proposes to implement a cluster approach to training, development and creation of high-tech industries in the field of processing of coal raw materials with obtaining end products with high added value. The main technological processes used are: preparation and burning of coal water slurry, based the finely dispersed coal preparation waste as well, liquefaction of demineralized coal and coal slime using a complex of high-energy influences (cavitation, ultrasonic and electric pulse), processing of waste from coal processing plants, bottom ash wastes as a basis for filling mixtures in the dead underground workings and open-pit mines. The implementation of the proposed cluster approach will allow the current scientific and practical problems facing the region in the field of coal mining and processing to be solved.

Penegakan Hukum Lingkungan Bidang Pertambangan Batubara dan Penguatan Lembaga Masyarakat Adat

This scientific article discusses the enforcement of environmental law in the field of coal mining and the strengthening of indigenous community institutions in Bungo Regency. The research approach method used in this scientific article is normative juridical and empirical juridical to be able to find the concept of enforcement of environmental law in the field of coal mining by examining the principles of mining law for the welfare of the community. The nature of environmental law should be able to prevent the occurrence of pollution and environmental damage and the existence of institutions of indigenous peoples in Bungo District has not functioned in the enforcement of environmental law in the field of coal mining business. Therefore the Bungo District government needs to strengthen the institutional of indigenous peoples so that it can function to enforce environmental law against coal mining to improve the welfare of the people in Bungo District.

A PROFICIENT DETECTION AND RESCUE ASSISTING SYSTEM TO COMBAT FIRE ACCIDENTS OCCURRING IN UNDERGROUND COAL MINES

Working in the field of Coal Mining (CM) is well known and considered among the most dangerous occupations when matched to many other industrial sectors[1], the safety issues associated with the CM workings gets worse when mining is carried out in the underground environment. In addition to the dangers coupled with the fall of roof, side walls and other harsh conditions in the Underground Coal Mine (UCM), the UCM suffers with additional threats such as the gas leakages, heating of coal and the other causes of fire accidents. All these factors raise concerns on improving the safety in the UCMs. The paper presented here focuses and recommends a safety system to tackle the accidents due to fire and to form a rescue assisting system.

Impact of nanopore structure on coal strength: A study based on synchrotron radiation nano-CT

Coal is a porous medium with complex pore structures. Nanopore structure in coal particle is the basic underlying factor driving coal particle strength. A better knowledge of nanopore structure – coal particle strength correlation is of great significance for coal mining and other fields of engineering problems. In this study, for the first time, we conducted an in-situ nanoscale characterization of structure and mechanical properties of coal particle using synchrotron radiation nano-CT. Furthermore, a parametric study of the nanopore structure – coal strength correlation was performed using numerical simulation, which is on the basis of manually-generated pore structure with predefined pore size distribution (PSD) and anisotropy value, and accurate PSD parameters. The nanoscale PSD in coal follows lognormal distribution. Improved quartet structure generation set (QSGS) method was developed to generate pore structure with predefined PSD and anisotropy value. The impact of porosity and pore structure anisotropy on coal particle strength was quantitatively investigated.

Performance enhancement of horizontal underground-to-inseam gas drainage boreholes with double-phase-grouting sealing method for coal mining safety and clean gas resource

Underground to inseam (UIS) borehole gas drainage is of significance for improving mining safety and turning hazardous methane into a clean gas resource. However, in the horizontal UIS borehole sealing by adopting cement-grout-based sealing method, an upper gap frequently occurs in the sealing section after cement-grout solidification, which could potentially be an air-leakage path and consequently decrease drainage efficiency. Despite extensive previous investigations on borehole sealing, very few studies have been reported in addressing the upper gap issue to enhance drainage performance. In this study, the air-leakage flow models in concentric ring and off-center ring seal gap of horizontal borehole were established. Then by adopting new expansive composite sealing (ECS) material, a double-phase-grouting (DPG) sealing method was developed to seal the upper gap. Based on theoretical fundamentals of seal-gap leakage, procedures and explanations of DPG sealing method were discussed. Finally, coalmine field trials were conducted to examine effects of DPG sealing method. Results show that: (1) there are positive correlations between air leakage quantity into borehole and the gap width, borehole diameter, pressure differences and eccentricity ratio. While the air leakage amount is negatively related to fluid viscosity and sealing-section length; and (2) because of adopting ECS material and the second-phase grouting specially designed for upper gap sealing, DPG sealing method is capable of sealing upper gap well to improve sealing quality. It mainly reflects in increasing drained gas concentration and prolonging the period of high-methane-concentration drainage. In comparison with traditional sealing method, the mean gas flow with DPG sealing method averagely rises by 30%. Outcomes of this study are expected to provide an effective way to solve upper gap issue and enhance drainage performance of horizontal UIS boreholes.

Organizational and Tactical Measures to Identify and Document Crimes in the Field of Illegal Coal Mining

In the article, the identification and documentation of crimes in the field of illegal coal mining as two interrelated processes are considered. Based on the consideration of the nature of crimes detection, directions and objects of documentation, the following proposals are formulated: on the formation of sources of operational search information; on the list of search features; on the list of operational investigative measures that are appropriate to carry out for solving the problem of bringing perpetrators to criminal responsibility. The list of open sources from which the primary information about the facts of being prepared, committed or having been committed crimes in the field of illegal coal mining is considered. A list of persons who may be involved in confidential assistance in order to obtain covert operational search information is also proposed. In order to ensure effective activity in detecting the facts of preparation and commission of crimes in the field of illegal coal mining, a list of search characteristics is proposed that can indicate facts of illegal activity. Suggestions regarding operational search measures have also been formulated, which allow the effective and timely detection, suppression and solving the crimes in the field of illegal coal mining.

Organizational and managerial measures to identify and document crimes of illegal coal mining (by the example of Kuzbass)

Based on the analysis of the operational situation in the Kemerovo region, the article formulates recommendations on the content of organizational and managerial measures aimed at ensuring the detection and documentation of crimes in the field of illegal coal mining. Considering the operational situation, the crimes in the field of illegal coal mining committed on the territory of Kuzbass were characterized. A description of the organizational structure and effectiveness of activities directed to fighting against crimes in the field of illegal coal mining realized by operational units of economic safety and anti-corruption of the Chief Administration of the Ministry of Internal Affairs of Russia in the Kemerovo region was made. The proposed organizational and management measures include: measures aimed at changing the organizational structure of the operational units of economic security and anti-corruption of the Chief Administration of the Ministry of Internal Affairs of Russia in the Kemerovo region. Measures to increase the efficiency of operational services for coal mining enterprises and territories in which illegal coal mining are considered as well. The recommendations for changing the organizational structure are based on the choice of the type of operational service. Measures aimed at improving the efficiency of operational services contain such recommendations as: the organization of interaction with various state and law enforcement agencies; the choice and change of the operational service regime, as well as the formation of open sources of operational search information.

Regional socio-economic aspects in the field of coal mining

Over time, the discovery of the deposit, the exploitation and processing of coal has led to the development and prosperity of many areas called “coal regions”. In the last decades we have witnessed the closing process of many exploitation capacities (underground mines or open pit quarries) with complex socio-economic and even cultural impact in the coal region and on the continent. Debates for or against “coal” with related arguments, policies, strategies and measures at global, regional, national and local level integrate holistically from the “resource” issue to large dynamic systems (energy, climate, urbanism). The relationship between the coal industry and the socio-economic aspects is multifaceted and not yet fully explored. Our paper proposes a statistically documented research on regional development using representative socio-economic indicators. The paper is aiming to present the current socio-economic state in Jiu Valley micro-region, as a result of the structural transformations / changes in the coal industry of Romania’s largest hard coal-fired coal basin.

СОВЕРШЕНСТВОВАНИЕ СТРАТЕГИЧЕСКОГО УПРАВЛЕНИЯ УСТОЙЧИВЫМ РАЗВИТИЕМ УГЛЕДОБЫВАЮЩИХ ПРЕДПРИЯТИЙ ЯКУТИИ НА ОСНОВЕ ИНТЕГРАЦИИ МЕХАНИЗМОВ ПРИНЯТИЯ РЕШЕНИЙ И ЭКОЛОГО-ЭКОНОМИЧЕСКОЙ ОЦЕНКИ БИЗНЕСА. ЧАСТЬ 2

The article discusses the possibilities of improving the strategic management of sustainable development of coal mining enterprises in Republic of Sakha, Yakutia. Based on the analysis of the activities of coal mining enterprises, the main positive and negative factors affecting the development of mining enterprises in Eastern Siberia are identified. The main problem considered in the proposed study is the insufficiently perfect state of the process of strategic management of industrial enterprises. The mechanism for developing and making strategic decisions in the field of coal mining and processing requires a certain adjustment, taking into account the fundamental economic, social, and environmental aspects of the concept of sustainability accepted by the scientific community. The main goal of the article is to develop and verify recommendations aimed at improving the strategic management mechanism for sustainable development of coal mining enterprises, which provides for the integration and close interaction of the key components of the management system - economic, social, environmental, and legal. Based on the analysis of theoretical studies, foreign and Russian practices of strategic management of industrial enterprises, the methodological base of the presented study is substantiated. The work is based on the synthesis of systemic, integrated, cultural approaches, theory and practice of crisis management, strategic management and evaluation of economic activity. The algorithm and an improved model for the development of managerial decisions of coal mining enterprises are presented. This model is based on the integration of strategic decision-making mechanisms and a comprehensive evaluation of the environmental, economic and socio-economic status of a coal mining and processing enterprise. Tools and recommendations for ensuring a balanced assessment of business projects are proposed. The improved mechanism provides for the synergy of key elements of the strategic management system of the coal mining enterprise, improving the quality of managerial decisions aimed at ensuring the sustainable development of the industrial enterprise.

An Automatic Recognition Method of Microseismic Signals Based on S Transformation and Improved Gaussian Mixture Model

The microseismic signals in the coal minefield are very complex because of its special environment with a large number of blast vibration signals, and how to effectively identify the microseismic signals is still a big problem. S transform (ST) and Manifold Learning (ML) methods are introduced to extract the characteristics of the microseismic signals, and Gaussian Mixture Model based on the improved Bee Colony optimization algorithm (IBC‐GMM) is established to identify the microseismic signals accurately. Firstly, the time‐frequency characteristics of microseismic signals in coal mine are extracted by ST analysis. It is found that there are obvious time‐frequency differences between rock‐fracturing signals and blast vibration signals. Blast vibration signals have short duration, high frequency, and complex frequency spectrum, and their dominant frequencies are mainly over 100 Hz. However, rock‐fracturing signals are relatively slow, with low frequency and stable spectrum change, and their dominant frequencies are generally below 100 Hz. Then, combining with the microseismic data of Xiashinjie coal mine in Tongchuan, China, the feature dimension reduction is carried out by Manifold Learning (ML) method, and the processed feature vectors are automatically recognized by IBC‐GMM. Field test results show that the method summarizes the characteristics of the microseismic wave which are difficult to emerge as the learning vector, and the features reflect the key features of microseismic signals well. The identification accuracy is as high as 94%, and its recognition effect is superior to other recognition models (such as traditional Gaussian Mixture Model based on Expectation‐Maximum (EM‐GMM), Backpropagation (BP) neural network, Random Forests (RF), Bayes (Bayes) methods, and Logistic Regression (LR) method). Therefore, IBC‐GMM could be used to mine engineering microseismic monitoring waveform recognition to provide the reference.

Eco-innovative competencies of mining engineers in the context of environmental management system requirements

The article is devoted to the analysis of mining engineers’ eco-innovation training key components associated with the formation of special knowledge and skills in the field of coal mining enterprises environmental management. The issues of the eco-innovation activities and the objectives of environmental management at coal mining enterprises are consistently considered. The article presents the examination of general and special requirements for the environmental education of mining engineers, which are to become the basis for the sustainable development of engineering projects in coal-mining industry.

Использование оптического волокна G-652 для контроля горного массива угольных шахт

Introduction. The relevance of using fiber-optic sensors to monitor the geomechanical state of the mine workings of coal mines of the Karaganda coal-mining field is extremely high, because they are super-categorical and dangerous in a sudden explosion of coal dust and methane gas during mining operations in hazardous mines. Fiber optic sensors have several advantages: explosion safety, high accuracy, measurement speed and have good linearity of characteristics. Aim. The use of optical fiber of the ITU-T G.652.D standard as a sensor for monitoring the geomechanical state of an array of coal mines, which is very promising in terms of creating a distributed monitoring system capable of timely signaling to personnel about the danger of a sudden collapse of a mine. Materials and methods. To develop methods for monitoring and measuring the geotechnical parameters of the workings, a simulation laboratory bench based on fiber-optic sensors was developed. The authors used a quartz single-mode optical fiber 9/125 μm (OS2) Corning SMF-28e + ®. The article proposes systems in two variants, depending on the tasks and functionality. In the first variant, the well-known method of optical reflectometry OTDR (Optical time domain reflectometer) is used. In the second variant, the values of the additional losses caused by the mechanical action on the optical fiber are controlled. Results. During mechanical action on an optical fiber microcracks occur, leading to a change in the properties of light and an increase in additional losses of the light wave passing through it. Conclusion. The use of ITU-T G.652.D standard optical fiber for monitoring the geomechanical state of an array of coal mine workings is very promising, since the VODs developed on its basis have sufficiently high accuracy, measurement speed and good linearity of characteristics.

Design of the Key Bearing Layer and Secondary Mining Technology for Previously Mined Areas of Small Coal Mines

In many underground coal-mine fields, where small scale coal mining had been performed, the available resources were not extracted fully. To extract the remaining coal, it is necessary to perform secondary mining. In this paper, a novel secondary mining technology is suggested incorporating a novel concept of building a key bearing layer (KBL) through backfilling in the previously mined areas to increase the extraction ratio, prolong the mine life, and avoid undesirable impacts on the limited coal resources and ecological environment. To analyze the influence of previously mined areas of small coal mines on the secondary mining, two new methods of determining the thickness of the KBL, choosing of the backfilling material, the slice backfilling method, ABAQUS finite-element analysis, field monitoring of displacement, and secondary mining technology were implemented. The results show that a minimum thickness of 5 m is required for the KBL in B909 panel of Pingshuo No. 2 underground coal mine to ensure stability of both the roof and coal walls during the secondary mining process. Ruimi-backfilling material was used to construct the cutting layer and KBL with different compressive strengths in the previously mined areas to carry out the slice backfilling, which met the mining requirements of the normal coal seam with reduced cost. Numerical simulation results showed that, when the secondary mining face was 20 m away from the previously mined areas, the secondary mining stress overlapped with the stress which was there from the previously mined areas to result in roof collapses. When the secondary mining face approached the previously mined areas, the roof of the goaf had a large area of collapse, which was beneficial to the stability of the KBL. It was possible to use the field-monitored displacements to validate the numerical-modeling results. The proposed novel secondary mining technology with backfilling in the previously mined areas of small coal mines turned out to be a safe, high-yielding and efficient mining method.

Gas content prediction and gas cascade control based on gas geological unit

The division of gas geological units in coal mine is the basis of studying the occurrence law of gas geology in coal mine field, which is of great significance to the prediction of regional gas content and gas emission. Taking Weijiadi coalfield in Jingyuan mining area of Gansu Province as an object, this paper divides the coalfield into gas geological units, according to the gas content of coal seams in different regions, targeted gas extraction measures are implemented, gas cascade control is implemented, regional gas abnormal emission is strictly prevented, and mine safety production is ensured.

Analysis of Coal Seam Gas Emission Based on Mine Gas Drainage Statistics

The statistics and analysis of mine gas extraction is very important for mine gas control, which provides a basis for the formulation of mine gas extraction plan. Because of its simple and convenient characteristics, it is favored by the engineering and technical personnel in the coal mine field, and has been widely used, and achieved good results. Based on the statistics of gas drainage in Weijiadi Coal Mine from 2008 to 2018, the characteristics and quantity of gas emission are analyzed according to the statistical results of gas drainage in Weijiadi Coal Mine, and the characteristics of gas emission in the process of driving in the main mining seam are predicted, and the mathematics relations of the length of driving roadway and the quantity of gas emission is obtained.