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Abstract Coal is currently the most important energy source in most countries. With the advent of information intelligence, more and more intelligent technologies are being applied in coal mine detection. A new model for coal mine drilling detection, which combines improved YOLOv5 and Gaussian filtering, is proposed to address the low efficiency and poor accuracy in manual detection of coal mine drilling. This new model incorporates attention mechanism and multi-object detection model on the basis of traditional YOLOv5. Due to factors such as equipment vibration and electrical interference in drilling detection, random noise is often mixed into the image signal data obtained. In order to effectively reduce the impact of noise on data and improve signal-to-noise ratio, Gaussian filtering method is studied for data denoising. This new model’s border regression loss value was 0.004 lower than the YOLOv5 loss value. This new optimization method’s accuracy was improved from 0.966 to 0.982. This new model improved the detection accuracy of small cracks by about 0.05. The detection depth of the coal seam in this new model was 9.54 m, which was closer to the true value than other methods. Therefore, using the new model to detect coal mine boreholes can effectively improve the accuracy of borehole detection images, which has a good effect on the analysis of coal mine rock layers. This new model has a good guiding role in the detection images and rock analysis research of future coal mine boreholes. The research has good research value in oil drilling inspection, natural gas pipeline monitoring, and quality inspection of industrial automation systems. This provides important technical support for future coal mine drilling image detection and rock analysis research.

Abstract Roof stability is a critical concern in coal mines, as the potential for roof collapse poses a significant risk to miners' safety and productivity. Roof stability is heavily influenced by the time-dependent properties of the rock mass above the workings. This study uses rock displacement testing to examine the effect of time-dependent properties on roof stability and resistance reduction in coal mines in Iran. The study employed laboratory-based rock displacement tests on samples collected from coal mines in Iran, subjected to varying stress levels over time, to simulate the gradual deterioration of rock mass strength in underground mining conditions. The samples were monitored for displacement under these conditions to quantify the reduction in roof resistance over time and assess its effect on roof stability. The study found that areas with high stress at equilibrium gradually fail with time, and the stress transfers from the failure zone into deeper solid rock. The results demonstrate that varying viscous parameters can lead to different relaxation behaviors and stress distribution. Furthermore, incorporating strength degradation into numerical simulation can capture the failure under creep conditions and improve the accuracy of predicting time-dependent roof failure. This research aims to enhance safety measures and reduce the risk of collapses by investigating the time-dependent properties of roof stability through rock displacement testing in Iran's coal mines. The study's innovative approach uses numerical simulation based on the viscoelastic-plastic model to simulate the time-dependent behavior of the rock and incorporate strength degradation into the simulation. The results provide valuable insights into the time-dependent behavior of rock mass in coal mines in Iran and contribute to developing strategies for improving roof stability and lessening the chance of roof collapses. The instantaneous elastic strain was 4.35 × 10–4, and creep simulation was activated to run for a time equivalent to 2 × 106 s.

In order to meet the requirements for the use of polyurethane for reinforcement in mines, the synthesis temperature of polyurethane needs to be lowered, and the flame-retardant and mechanical properties of polyurethane should also be considered comprehensively. Factors affecting the synthesis temperature of polyurethanes are investigated, low heat storage polyurethanes that meet the temperature requirements for use in plugging crushed coal bodies in coal mines are formulated, and the synthesized polyurethanes are characterised for their flame retardant properties by FTIR, SEM, TG-FTIR and CONE experiments. It was found that in this paper, a new type of polyurethane for coal mines was formed by flame retardant modification of polyurethane by adding nano-system flame retardant and phosphorus-system flame retardant, and the synthetic reaction temperature of the material could reach as low as 51.2 °C, and the pyrolysis onset temperature was increased to 286 °C. The experimental results show that the flame retardant property of this synthetic polyurethane has been significantly improved, and the heat accumulation effect of the synthesis process on the surrounding coal body has been greatly reduced. The physical properties and thermal stability of this synthetic polyurethane in the grouting process meet the safety requirements for use in underground coal mines.

Abstract There is an urgent need to develop optimal solutions for deformation control of deep high‐stress roadways, one of the critical problems in underground engineering. The previously proposed four‐dimensional support (hereinafter 4D support), as a new support technology, can set the roadway surrounding rock under three‐dimensional pressure in the new balanced structure, and prevent instability of surrounding rock in underground engineering. However, the influence of roadway depth and creep deformation on the surrounding rock supported by 4D support is still unknown. This study investigated the influence of roadway depth and creep deformation time on the instability of surrounding rock by analyzing the energy development. The elastic strain energy was analyzed using the program redeveloped in FLAC3D. The numerical simulation results indicate that the combined support mode of 4D roof supports and conventional side supports is highly applicable to the stability control of surrounding rock with a roadway depth exceeding 520 m. With the increase of roadway depth, 4D support can effectively restrain the area and depth of plastic deformation in the surrounding rock. Further, 4D support limits the accumulation range and rate of elastic strain energy as the creep deformation time increases. 4D support can effectively reduce the plastic deformation of roadway surrounding rock and maintain the stability for a long deformation period of 6 months. As confirmed by in situ monitoring results, 4D support is more effective for the long‐term stability control of surrounding rock than conventional support.

Abstract Coal mine galleries and construction tunnels are commonly excavated using roadheaders. Estimating the performance of roadheaders is crucial for planning and cost estimation when planning tunnel or tunnel projects. The aim of this study is to derive generalized performance prediction models including Schmidt hammer value, needle penetration index, and volumetric joint count for roadheaders used in coal mines. The performance measurements of axial and transverse type roadheaders were carried out in six different coal mines. Schmidt hammer tests, needle penetration index tests, and of volumetric joint count measurements were also performed at the locations where the performance measurements were conducted. The extensive data were evaluated using multiple linear and nonlinear regression analysis. The developed formulas were evaluated using statistical tests. The Equations that include the Schmidt hammer value or needle penetration index value in addition to cutter head power have been shown to be unreliable. However, the equations that include Schmidt hammer value or needle penetration index value in addition to cutterhead power and volumetric joint count have been shown to be reliable. This study concludes that the developed reliable equations can be used for the performance assessment of roadheaders used in coal mines.

Underground coal mines are always faced with their own specific uncertainties. These uncertainties lead to safety risks and ultimately result in chaos and safety disturbances. Human factors are among the uncertainties that play a vital role in various industries, including underground coal mining. For instance, they affect safety, production processes, machinery maintenance, and productivity. Risk management is one of the primary methods for improving safety in underground coal mines. Risk management is a process that helps identify, assess, and mitigate risks and uncertainties. Its main goal is to protect resources, enhance safety, and increase efficiency through informed decision-making. This article examines the role of human factors in risk assessment of coal mines; it first classifies human factors and then uses the Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (Fuzzy-TOPSIS) method for pairwise comparison to evaluate the risks of underground coal mines. The TOPSIS method is a multi-criteria decision-making technique that operates based on the distance of options from the best and worst solutions. This method ranks the options based on specific criteria and assists in selecting the optimal option. The results of the study on human factors indicated that carelessness, negligence, and distraction had the greatest impact on the risk assessment of underground coal mines, with a similarity index of 0.6516, while the level of education had the least impact with a similarity index of 0.2871.

Gas explosion accidents are the most serious type of accidents that cause losses in coal mines. In order to explore the pattern of unsafe actions related to such accidents and to regulate the behaviors of relevant work types in the operation process of underground coal mines, 116 serious gas explosion accidents in coal mines from 2005 to 2022 were statistically analyzed to explore the distribution characteristics of unsafe actions in different dimensions of gas explosion accidents in coal mines, to discuss the reasons for their occurrence, and to put forward targeted measures. The results show that: from the aspect of the coupling of work type and accident location, blasting operators and tile inspection operators have the highest number of unsafe actions in the face of digging and coal mining, respectively; from the aspect of the coupling of work type and laws and regulations, blasting operators are the operators with the highest frequency of violating the regulations, and the most violated regulations is the Coal Mine Safety Regulations.

This paper considers extreme dusty conditions at workplaces in underground coal mine. These extreme conditions stem from various physical factors that affect employees’ performance. The extreme effect of the dust can significantly contribute to permanent health damage or even the death of employees. In this study, we present and discuss the results of measurements of airborne dust and respiratory dust taken during wall cutting in a coal mine and propose effective measures to reduce the burden on the life and health of employees and the environment.

Abstract Globally, studying the impact of coal mining on groundwater remains challenging. This is because the exploitation of coal resources and the sustainable development of groundwater resources involve economic, social, and environmental aspects. Over the last few decades, the number of publications on groundwater-related studies in coal mining areas has increased. However, they are not currently reviewed in a widely visible manner through bibliometric analyses. This study investigated groundwater research in coal mining areas worldwide using scientometric analysis based on 1196 articles from the Web of Science database to provide a global perspective and gain quantitative insight into research frontiers and trends in the field by mapping existing knowledge. We analyzed the key contributors and development processes of coal mine groundwater research and identified four research frontiers based on scientometric mapping results with an understanding of the research field: numerical modeling, conceptual modeling and mechanisms, feedback mechanisms between anthropogenic-environmental systems and groundwater systems, ground subsidence management, groundwater quality evaluation and risk assessment, and groundwater resource management in coal mines. Finally, we summarize the current challenges and propose methods to promote the green mining of coal resources and the sustainable development and management of groundwater resources.

In the context of sustainable development, revitalising the coal sector is a key challenge. This article examines how five innovative technologies can transform abandoned or in-use coal mines into sustainable energy centres. From solar thermal to compressed air energy storage, these solutions offer a path to a more sustainable future while addressing the decline in coal production. This approach not only promotes energy efficiency but also contributes to the mitigation of environmental impacts, thus consolidating the transition to a more responsible energy model. Thus, in this document, the reader can find the explanation of why we have opted for these technologies and not other existing ones. In addition, the economic, environmental and technical feasibility of the different technologies is analysed. Finally, real cases of the successful application of these technologies will be presented once they have gone beyond the project idea phase, and the reasons why we are calling for their transposition to the coal industry in the search for its revitalisation will be explained.

In order to solve the problem of low safety and efficiency of underground mine vehicles, a path planning method for underground mine vehicles based on an improved A star (A*) and fuzzy control Dynamic Window Approach (DWA) is proposed. Firstly, the environmental information is analyzed, and the proportion of obstacles is introduced into the A* algorithm to optimize the heuristic function to improve its search efficiency in different environments. Secondly, for the global path, the key node selection strategy is proposed, the node selection method is optimized, and the redundant nodes are deleted. The path is optimized by using a 3 times Clamped-B spline to improve the smoothness of the path. Then, based on the principle of fuzzy control, fuzzy rules are established, and a DWA fuzzy controller is designed to improve the environmental adaptability of the DWA algorithm. Finally, on the basis of the global path, the key node is used as the local target point of the DWA, and the fusion of the improved A* and DWA algorithm is realized. Finally, experiments are conducted to verify the effectiveness and feasibility of the proposed path-planning method. The average deviation of the path is controlled at ±0.109 m, which basically meets the path planning needs of underground mine vehicles.

Ningxia province is a major coal-producing province in Northwest China that contributes significantly to China’s economic development. However, long-term coal mining in Ningxia province has brought many environmental issues, such as surface collapse, destruction of water resources, air pollution, and random stacking of waste coal gangue. Hence, promoting the coordinated development of coal mining and environmental protection and improving the overall level of green coal development have become two critical issues for the development of the coal industry in this region. According to the current situation of coal mining in Ningxia province, the technical problems that require immediate resolution, such as the bottleneck of basic theory and technology, imperfect technical standards and norms of green development, insufficient support of green development technique and equipment, and lack of demonstration guidance and policy support were summarized. Moreover, the strategic thought, development blueprint, and strategic objectives of green development of coal mines were put forward based on the realistic demand of future development of the coal industry in Ningxia province, forming the overall strategic layout in this region. On this basis, the technical paths for future green development of coal mines in Ningxia province were proposed from various perspectives, primarily water resources protection technology of coal mining, large-scale and low-cost treatment technology of mine water, surface ecological restoration technology of mining area, intelligent and green mining technology, and clean coal technology. Finally, some feasible suggestions for the green development of coal mines in Ningxia province were proposed. We should clarified the concept and goal of green development and actively implement green mining to promote the ecological environment and ecological civilization to a new level and realize the high-quality, sustainable development of the coal industry in Ningxia province.

Globally, the major source of environmental pollution as a result of mineral exploitation and processing is acid mine drainage (AMD). AMD refers to outflowing streams of acidic constituents from pyrite-bearing ore mines. The exposure of pyrite (FeS2) in coal waste dumps to atmospheric oxygen and water in the presence of microbial communities promotes the formation of sulphuric acid which leaches out the inherent heavy metals into the mine discharge, a phenomenon called pyrite oxidation. AMDs are usually characterized by a convoy of toxic heavy metals, most of which are transition elements (copper, nickel, zinc, etc.) and arsenic at concentrations higher than the limits permitted by environmental regulations. The impact of this acidic discharge from coal mines on downstream/underground waters and farm lands within the corresponding mining zones have been severally reported by previous researchers, but not so much have been discussed on extensive prediction and remediation. It is in view of this that the current paper reviews the need for extensive prediction and remediation approach for coal mines under the following subheadings; General introduction, AMD sources identification, representative sampling, adoption of a prediction model, determination of AMD potential and quality via static and kinetic tests and the development of an economically sustainable remediation strategy. It is thought that this article would be useful to academia as well as policy makers that are responsible for the development and implementation of environmental regulations in coal mines.

ObjectiveCoal mining activities have continuously introduced heavy metals into the soil–crop system, causing increasing damage to crops. This study integrated the analysis of the heavy metal contamination status and human health risk in soil and maize near coal mines to help formulate control strategies for soil quality, maize production, and safe consumption.MethodThis study was carried out on maize agricultural land near a coal mining plant. Heavy metal contamination was assessed by the geo-accumulation index (Igeo), enrichment factor (EF), and bioaccumulation factor (BCF). The Monte Carlo simulation was used to estimate the probabilistic health risk of heavy metals exposure in soil and maize. The relationship between the concentration of heavy metal in the soil and that in maize was further visualized by correlation analysis and random forest analysis.ResultsThe results revealed that the mean concentrations of soil Ni, Cu, As, Cd, Sn, Zn, Pb, and Hg were all above the local background level. Ni was the most severely polluted heavy metal in maize and had a concentration higher than the risk control standard for corn in China (NY 861-2004). The Igeo values of all heavy metals were low, and EF values showed enrichment in V, Cr, Ti, Ni, and As. The assessment of probabilistic health risk exposed by heavy metals in soil and maize indicated that 1.16 and 1.46% of residents exceeded the carcinogenic risk level due to heavy metal exposure from soil and maize, respectively. Children were the most sensitive to maize and soil heavy metal exposure in the contaminated area. Ingestion of heavy metals was associated with the highest health risk to residents, followed by dermal contact and inhalation. As and Cr in soil and Cr and Ni in maize had the greatest impact on human health risk. Furthermore, maize heavy metals were affected the most by soil Cr, Cd, and V.ConclusionThese results may provide useful information for human carcinogenic risk associated with soil and maize heavy metal exposure due to coal mining activities.

To improve the accuracy of personnel positioning in underground coal mines, in this paper, we propose a convolutional neural network (CNN) three-dimensional (3D) visible light positioning (VLP) system based on the Inception-v2 module and efficient channel attention mechanism. The system consists of two LEDs and four photodetectors (PDs), with the four PDs on the miner’s helmet. Considering the height fluctuation of PD and the impact of wall reflection on the received light power, we adopt the Inception module to perform a multi-scale extraction of the features of the received light power, thus solving the limitation of the single-scale convolution kernel on the positioning accuracy. In order to focus on the information that is more critical to positioning among the numerous input features, giving different features of the optical power data corresponding weights, we use an efficient channel attention mechanism to make the positioning model more accurate. The simulation results show that the average positioning error of the system was 1.63 cm in the space of 6 m × 3 m × 3.6 m when both the line-of-sight (LOS) and non-line-of-sight (NLOS) links were considered, with 90% of the localization errors within 4.55 cm. During the experimental stage, the average positioning error was 11.12 cm, with 90% of the positioning errors within 28.75 cm. These show that the system could achieve centimeter-level positioning accuracy and meet the requirements for underground personnel positioning in coal mines.

Abstract Tsurang, a major river in the Mokokchung district of Nagaland, northeast India, shares great aspects of traditional importance for the Ao Naga tribes and is a part of natural commodity providing water to the agrarian community for irrigation and livestock rearing. However, various environment detrimental activities are practiced along the course of the riverbank, particularly coal mining and agriculture. The present study was conducted to examine the seasonal water quality index (WQI) of the Tsurang river from three selected sampling stations. Overall, the water quality status was rated as “Good” in winter and spring while “Poor” in summer and autumn. In all the seasons, downstream (S3) located at the human settlement area presented higher WQI values compared to upstream (S1) and midstream (S2). The parameters such as turbidity, DO and BOD played a central role in affecting the WQI; although, no such significant roles in case of nutrient elements were observed in affecting the water quality. The WQI revealed that Tsurang river water is deteriorated due to coal mining and other anthropogenic activities practiced along the stretch of the river and the water needs to be pretreated before consumption. Therefore, proper management strategies and conservation efforts should be enforced and regulated by policymakers to protect the river from further contamination.

In the context of carbon neutrality, the phase-out of coal from the energy structure has resulted in numerous old coal mines that possess abundant underground space resources suitable for underground pumped hydroelectric energy storage (UPHES). Site selection and estimation of potential are critical to the planning and implementation of UPHES in old coal mines. This paper introduces a two-step site selection concept, including a screening assessment followed by a comprehensive assessment, to determine suitable locations for UPHES. The screening indicators in the screening assessment comprise geological features, mine water disasters, and minimum installed capacity, while the analytic hierarchy process (AHP) is applied in the comprehensive assessment. Additionally, coal mines in Henan Province are preliminarily screened through the screening assessment and the potential for UPHES is thoroughly investigated. The estimated volume of the drifts and shafts in old coal mines is approximately 1.35 × 107 m3, while in producing coal mines, it is around 2.96 × 107 m3. Furthermore, the corresponding annual potential for UPHES is 1468.9 GWh and 3226.3 GWh, respectively. By consuming surplus wind and solar power, UPHES is able to reduce 4.68 × 105 tonnes of carbon dioxide (CO2) emissions. The study provides preliminary guidance for policy-makers in developing UPHES in old coal mines.

Coal is the most extensively used nonrenewable energy source worldwide. In Pakistan coal is mostly mined by underground mining methods under poor and unsafe working environment. In this study, accident records of underground coal mines of Cherat coal field were collected and analysis was carried out to understand the consequences, time of occurrence and causes of accidents. Besides, occupation of a victim, responsible party and effects on production were also considered in present study. The relationship between workers’ age and severity rate was examined using regression analysis. The main causes of accidents were the fall of the roof, mine gases, electrocution, oxygen deficiency and slip fall. At Cherat coalfield, for every two mines, there is one fatality and most of the accidents occur due to roof fall between 10:00 am to 12:00 noon. It is due to the stress of production efficiency. Moreover, there is a negligible impact of accidents on coal production at Cherat coalfield from 1994 to 2015.

In this article, variants of technological designing of new mining enterprise levels for obtaining the skills of engineering task execution are considered. The complex approach for the justification of a mine’s parameters is examined. The combinations of quantitative and qualitative parameters for designing new coal-face and preparation works, transport, ventilation, and draining-out of gases, pumping, and mineral deposits while keeping cost reduction in mind for all stages of mining enterprise operations are presented. The obtained results allow us to lay the foundations for optimizing the parameters of the development system and the rational order for the coal reserves, under the changing mining and geological conditions of coal field deposit development. Conclusions regarding the implementation of the multivariance solutions in new coal mine level designing are made on the basis of undertaken investigations. The obtained results with sufficient accuracy in a practical application can be used to determine the development of new coal mine levels.

The injury rate in underground coal mining is extremely high. One of the factors leading to injuries in underground mining is rock bursts. Although rock bursts are not the most common cause of injury in this industry, their consequences are extremely severe. At the same time, the level of injuries as a result of the manifestation of this factor remains high and almost does not change over the past years. The paper presents a method for determining the risk of injury of varying severity as a result of rock bursts. Multifunctional security systems that allow obtaining information about the state of the rock mass are analyzed. Based on the data obtained from these systems, the probability of a rock burst is assessed. The paper also deals with the processing of statistical information on light, severe and fatal injuries caused by rock bursts in the coal mines of the Kuznetsk coal basin. On the basis of statistical data and the results of measurements of the main parameters of the rock mass, the value of the individual risk is determined. It is advisable to correlate the obtained value with the average occupational risk in production.

In response to the Paris climate agreement, the Chinese government has taken actions to improve the energy structure by reducing the share of coal-fired thermal power and increasing the use of clean energy. However, due to the extreme shortage of large-scale energy storage facilities, the utilization efficiency of wind and solar power remains low. This paper proposes to use abandoned coal mine goafs serving as large-scale pumped hydro storage (PHS) reservoir. In this paper, suitability of coal mine goafs as PHS underground reservoirs was analyzed with respects to the storage capacity, usable capacity, and ventilation between goaf and outside. The storage capacity is 1.97 × 106 m3 for a typical mining area with an extent of 3 × 5 km2 and a coal seam thickness of 6 m. A typical goaf-PHS system with the energy type αw=0.74 has a performance of 82.8% in the case of annual operation, able to regulate solar-wind energy with an average value of 275 kW. The performance of the proposed goaf-PHS system was analyzed based on the reservoir estimation and meteorological information from a typical region in China. It has been found that using abandoned coal mine goafs to develop PHS plants is technically feasible in wind and solar-rich northwestern and southwestern China.

The present study was conducted at a coal mining affected forest and a non-affected forest to analyze the seasonal changes in soil physico-chemical properties, incorporate additive and weighted soil quality index (SQI) to determine the soil quality and check the affected forest soil pollution status. Comparative SQI shows that the non-affected forest presented higher SQI in all the seasons (winter, spring, summer and autumn). However, in both the forest the seasonal additive and weighted SQI was categorised as autumn > summer > spring > winter and the overall SQI of the soil depth was ranked as 0–10 > 10–20 > 20–30 cm. The Single pollution index (PI) points out that cadmium (Cd) was the main potential contributor to soil pollution while the Pollution load index (PLI) and Nemerow integrated pollution index (NIPI) revealed moderate soil pollution status. The result summarized that coal mining activities can elevate soil deterioration rate, such as loss in soil organic carbon, reduction in nutrient availability, and slowing down the rejuvenating process of forest soil.

The operation of coal mines is intricately linked with emitting a large quantity of coal mine methane, and in most cases, this methane releases into the atmosphere. In total, according to statistics, coal mining enterprises emit 8% of anthropogenic methane, determining a contribution to greenhouse gas emissions to the amount of 17%. There are various means for coal mine methane utilization. In this study, the concept “Coal-Energy-Information” is proposed. This concept implies both the construction of data processing centers on the industrial sites of coal mines and the usage of coal mine methane. Coal mine methane can be used as a primary energy source for the energy supply of data processing center consumers as well as coal mine consumers with necessary energy resources (electricity, heat, and cooling). Within the framework of the proposed concept, three options of coal mine methane utilization are considered. The first option is the use of gas genset for electrical and thermal energy generation (cogeneration) and their usage for coal mine and constructed data processing centers and consumers’ power supply. The second option is absorption refrigerator usage (with coal mine methane direct burning) for cooling the IT equipment of constructed data processing centers. The last one is the use of a gas genset and absorption refrigerator (trigeneration) for constructed data processing centers’ and coal mine consumers’ energy supplies (electricity, heat, and cooling). In conclusion, it is noted that proposed concept is closely correlated with the program for the development of the coal industry in Russia for the period up to 2035, since it allows creating a base for the implementation of innovative technologies based on digital platforms that ensure the development of coal mining technology without the constant presence of personnel in underground mining facilities.

Archeological discoveries have identified China as one of the first countries in the world to use jet. However, many differences are evident between the jet currently found in existing mines and the archaeological discoveries of cultural relics in terms of texture and quality according to the definition of organic gem jet in gemology. This paper reports the results of microscopic analysis and coal quality analysis of the coal and jet samples from coal seams in Fushun Open-pit Mine and Datong Coalfield. The findings reveal that the physical and chemical composition of coal in different mining areas differs markedly. However, the differences between jet and coal in both mining areas are similar; that is, jet has lighter density and greater hardness (2–4) compared to coal, as well as elasticity (engravability), and both jet and coal occur in the (rock slurry) hydrothermal environment. Lastly, the analysis shows that the formation of jet depends on rubber-like hydrocarbon coal with a high degree of corruption in a sedimentary environment under the vulcanization of a hydrothermal, high-sulfur environment.

Coal mine activities lead to the release of potentially toxic elements (PTEs) to the surrounding areas. The present study concerns the health risk caused due to the exposure of PTEs (Hg, As, Cd, Cr, and Pb) in the children residing in the areas around coal mines. The PTEs content and bioaccumulation coefficient (BAC) in the plant, viz., Albizia lebbeck and Madhuca longifolia growing on the nearby soils of the coal mine affected areas were also estimated. The results demonstrated that the hazard quotient (HQ) for Cr (0.211) in the roadside soil (RSS) was higher than other PTEs. The hazard index (HI) was also at the maximum in the RSS (0.553) followed by the core zone soil (0.541). In RSS, Cr contributed the maximum for the HI value (38%) which elucidated that Cr might cause health problem in the long term. The Cr concentration (5.49 mg kg−1) was also higher than other PTEs in the plant leaves of M. longifolia and was two-fold higher than A. lebbeck. Except Cd, the accumulation of other PTEs in the leaves of both the species were low, which could be due to their low availability in soils. The BAC for Cr in M longifolia was comparatively higher than A. lebbeck and was found at the maximum for Cd (0.29) in M longifolia. The outcomes of the study elucidated that although there is no severe health risk in children, the data indicated that the prolonged exposure to PTEs might lead to serious health issues.

The coal area of Baixo Jacuí, in Rio Grande do Sul, is known as the cradle of the coal industry in Brazil. The beginning of this industry occurred in the second half of the nineteenth century, but its assertion within the Brazilian industrial context occurred during the period of the war effort when thousands of tons of ore were extracted from the subsoil of the two main mining locations of the time: Arroio dos Ratos and Butiá. This article tries to understand how the workers of the coal mines of the region were positioned in front of this conjuncture characterized by profits of one side and super exploitation by another one. Firstly, it is sought to discuss the way the war effort discourse has toured the region through different segments of the coal community, seeking to raise and legitimize the maximum effort of the mine workers. The following are the exploitation levels to which the miners were subjected in this context and some of their main demands and forms of resistance. Finally, the position of the class entity is observed before the pressure of the mining companies and of the mining category itself. For this article documents of the documentary funds “CADEM” and “Sindicatos”, both belonging to the collection of the Historical Archive of Mining, located in the city of Arroio dos Ratos.

The paper proposes a new approach to the distribution of investments in a group of coal mining enterprises. For the first time, the model for assessing the production efficiency of enterprises as a derivative of the level of resources attracted to the number of products, with the main criterion being the efficiency of reserves extraction, is suggested. The study of changes in reserves (in this case, a coal) over time allows us to predict the technical and economic indicators of the enterprise in the long term. The work solves an urgent scientific and practical task, which is to study the impact of investments on the increase in productivity of coal mines. The authors suggest applying the criterion of «economic reliability» to solve the problem of redistributing funds between enterprises engaged in the extraction of identical products. Based on the assessment of economic reliability, a general conclusion is drawn on how much investment should be attracted to increase production, and all enterprises are considered. The practical value of the research is to establish the dependence of the level of production growth on attracted investments for enterprises with different levels of economic reliability. It has been established that the most effective option for transforming the mines of the coal-mining region is to compensate for a possible decrease in production volumes, their necessary increase due to the additional load of effective existing mines and, as a rule, with lower capital costs. All this confirms the high feasibility of creating reliable methods for ranking mines. The calculations of the optimal values of the mine capacity indicate the potential capabilities of the mines of the State Coal Company (SCC), which are provided with significant reserves and have a fairly high level of economic reliability. Using a dynamic approach to choosing the parameters of the mine transformation to break-even mode can reduce the costs of the enterprise and ensure its sustainable development by the timely implementation of new investment projects taking into account the optimal effective life of the mine.

This paper presents a detailed account of computational fluid dynamics (CFD) simulations undertaken to investigate the influence of intake (ventilation) air velocities on the flow patterns of diesel particulate matter (DPM) generated by a man-riding vehicle operating in a straight rectangular cross section tunnel in an underground coal mine. The simulation results are validated against an earlier experimental study. At a sampling station 10 m downstream of the vehicle, the DPM concentration was seen to decrease rapidly with increasing intake air velocity. For air velocities of 0.5 m/s, 1 m/s, 2 m/s and 3 m/s, the DPM concentration was estimated to be 233 µg/m3, 131 µg/m3, 116 µg/m3 and 1 µg/m3 respectively. At 10 m downstream of the vehicle, if the intake air velocity is reduced from a base value of 1.26 m/s by 40% and 60% of the base value, the average DPM concentration increased to 58% and 123% respectively. If the intake air velocity is increased by 58% and 98% of the base case value, the average DPM concentration decreased to 44% and 78% respectively.

During the past 20 years, due to the rapid development of China's economy, the amount of coal mining activities has rapidly increased, which has led to a large increase in the number of mined-out areas. Therefore, the role of geophysical exploration in coal fields has changed from the detection of coal resources to engineering geological environmental investigation. The safety, efficiency, and green production of coal mines require more advanced geophysical detection technologies. In particular, the accurate detections of the locations of water-rich mined-out areas, as well as concealed water diversion channels, have become the main focuses of coal electrical methods in recent years. Therefore, electromagnetic methods have become the main means of hydrogeological investigations and deep explorations in mine-out coal areas. In this study, a common DC method was briefly introduced, along with an induced polarization method. Then, three representative electromagnetic sounding methods, including a surface frequency-domain electromagnetic method, time-domain electromagnetic method, surface to air electromagnetic method, and mine electromagnetic method, were respectively introduced.

The hidden roadway of small coal kiln with shallow buried depth under expressway is a hidden danger of roadbed safety. It is easy to detect the original stratum, but it is difficult to detect the roadway of small coal kiln under the stone roadbed filled with stone. In view of this situation, high-density resistivity method is used to detect the local area of Tongchuan section of G65 expressway. Electrodes are arranged in the way of small polar distance, shallow drilling and grouting cement slurry for data acquisition. Weighted average interpolation method is used to eliminate the influence of inhomogeneous stone layers on data in the data pretreatment stage, and then least square inversion with smooth restriction conditions is carried out to obtain the known data of abnormal characteristics of water-accumulated roadway in small coal kiln. According to this method, all the data in the exploration section are processed, and three abnormal areas are found, which have been verified by drilling.

The increase in functional requirements for coal mine safety systems at the level of legislation led to the use of multifunctional and unified safety systems. This led to the appearance on the market of many systems operating on various technologies, both completely new and modernized old ones. Leaders and technical specialists of mining companies faced the problem of selecting and evaluating various technical solutions for a complex set of equipment. In this article, we propose criteria for the expert evaluation of complex systems, in particular the IFSW of coal mines. Based on the analysis of the numerical criteria indicators, the architecture of the optimal computer MS network is proposed taking into account the factors operating in coal mines for devices with Ex marking RO / RV and, undoubtedly, determining the design of communication nodes and mobile devices of infrastructural communication channels. Recommendations for solving emerging problems are given, possible development directions are considered.

An important factor in the development and retention of the region is availability of energy resources on its territory. They facilitate the development and maintenance of military infrastructure, it enables the effective development of transport and industry. The article examines the experience of using coal mines of Sakhalin Island to supply the Siberian Flotilla and the creation of the Sakhalin Society, which was supposed to solve the energy, economic and demographic problems of the region. The author analyzes the reasons for the failure of the Russian administration’s attempts to use Sakhalin’s coal deposits as an alternative to buying coal in foreign countries

This study was aimed to analyze the thallium pollution and assess the potential ecological risks in the vicinity of coal mines in Henan province, China. We studied 90 surface farmland soil samples from 9 representative coal mines. The Tl concentrations were determined and the potential ecological risks were evaluated. Investigations revealed the farmland soils were modestly contaminated and the trace elements in coal mining areas transferred to the surface soils. Soil Tl contents and potential ecological risks in coal mining areas were significantly increased compared with the original soils which came from the villagers’ mud houses built 40 years ago. The soil Tl concentrations ranged from 0.25 to 0.77(mean = 0.46) mg∙kg−1, which were higher than the original level (0.42 mg∙kg−1). The potential ecological risk index of Tl ranged from 24.00 to 73.2 (mean 44.08), representing a moderate pollution level as a whole of the soils in Henan. In general, high Tl concentrations and high potential ecological risk were found around SHQ and DTG. The soil Tl concentrations exceed the original level and pose noticeable ecological risks.

Gas explosion has always been an important factor restricting coal mine production safety. The application of machine learning techniques in coal mine gas concentration prediction and early warning can effectively prevent gas explosion accidents. Nearly all traditional prediction models use a regression technique to predict gas concentration. Considering there exist very few instances of high gas concentration, the instance distribution of gas concentration would be extremely imbalanced. Therefore, such regression models generally perform poorly in predicting high gas concentration instances. In this study, we consider early warning of gas concentration as a binary-class problem, and divide gas concentration data into warning class and non-warning class according to the concentration threshold. We proposed the probability density machine (PDM) algorithm with excellent adaptability to imbalanced data distribution. In this study, we use the original gas concentration data collected from several monitoring points in a coal mine in Datong city, Shanxi Province, China, to train the PDM model and to compare the model with several class imbalance learning algorithms. The results show that the PDM algorithm is superior to the traditional and state-of-the-art class imbalance learning algorithms, and can produce more accurate early warning results for gas explosion.

The subject of the article is a new method that I have developed for calculating a multi-asset break-even for multi-assortment production, extended by a percentage threshold and a current sales ratio (which was missing in previously published methods). The percentage threshold provides unambiguous information about the economic health of a company. As a result, it became possible to use it in practice to evaluate the activities of economic entities (mines) and to perform modelling and optimisation of production plans based on different variants of customer demand scenarios. The publication addresses the complexity of the problem of determining the break-even in multi-assortment production. Moreover, it discusses the practical limitations of previous methods and demonstrates the usefulness of the proposed method on the example of hard coal mines.

Background and aims: coal mines fire is one of the most important problems in all coal production countries. The purpose of the present study was the risk assessment of fires based on Fault Tree Analysis method in fuzzy environment in the coal mines. Methods: In this research, according to a review of all the latest, known and credible studies about fires from around the world, many important and effective parameters were identified. Afterwards, the causes of firewere determined using FTA method. In order tocalculate the probability ofbasiceventsandeventually reach therate ofoccurrence ofthe topevent(risk of fire) andregarding this fact thatthe possibility ofachievingpreciselythe basic eventsinthefault tree of this event is difficultandwithuncertainty, so fuzzy logic and fuzzy numbers were used to assign probability weight to basic events. Then the probability of top event was determined using the appropriate equations. The critical Minimal Cut Sets (MCS) were determined using Fussell-Vesely equation. Results: The results showthatthe probability ofthe risk offirein Eastern Alborz Coal Mines is 39.38%, sothat it is thehighlevels ofrisktostaff involved inthisvital and important industry. The existence of gasandcoal dustin site ofwelding, was identifiedasthe most criticalparameter. Conclusion: The using offuzzy logicinfault treeanalysis method increaseaccuracyand reduceuncertaintyincalculations. Also it makes the evaluationseasier.

Analysis of the relevant literature has shown that only few researches are dealing with the bearings dynamic behaviour in real environmental conditions - where high concentration of solid contaminant particles is evident. There is still no established mathematical correlation between bearings vibration characteristics, working time and concentration level of contaminant particles in their grease. Solving this problem was the main goal of research described in this paper. First step was thorough analysis of the chemical composition and structure of contamination particles directly causing the sample bearings failure on open pit coal mines. After that, specific experimental methodology was developed and implemented. Finally, by processing of the experimental results, new mathematical correlation between listed bearings characteristics was determined.

The method of increasing the efficiency of using one of the most common means of auxiliary transport in underground coal mines—suspended monorails—is presented. Increase of velocity is one of the key parameters to improve the efficiency and economical effect related with the underground auxiliary transport. On the other hand, increasing the velocity results in bigger value of force acting on the suspended monorail route and its suspensions. The most important issue during increasing the velocity is ensuring the required safety for the passengers and not overloading the infrastructure. In order to analyze how increasing velocity influences the level of loads of the route suspension and the steel arch loads, the computational model of suspended monorail was developed. The computational model included both the physical part (embedded in the program environment based on the Multi-Body System method) and the components of the monorail control system. Two independent software environments were cooperating with each other through the so-called co-simulation. This model was validated on the base of results obtained on the test stand. Then, the numerical simulations of emergency braking with different values of velocity were conducted, which was not possible with the use of physical objects. The presented study can be used by the suspended monorail’s producers during the designing process, and leads to increase the safety on underground transportation routes.

The influence of biogenic surfactants on the morphometric and oxidative characteristics of sorghum (Sorghum bicolor subsp. drummondii) during its growth on waste dump substrates of coal mines was investigated. It was found that presowing seed treatment with biosurfactants solutions – rhamnolipid biocomplex (RBC) or trehalose lipid surfactants (TL) – improved growth and oxidative parameters of plants, indicating the increase of sorghum resistance to adverse growing conditions. The best results were achieved when sorghum was grown on red substrate: shoots mass was increased in 2.20 times with RBC and in 1.19 times with TL, the root mass – in 2.30 and 1.71 times. Changes in antioxidant indicators of plants suggested the reducing of negative impact of unfavorable environmental factors of waste dumps. The content of malonicdialdehyde in sorghum on the red substrate was reduced by 15 % with RBC and 11% with TL and on the black substrate indicators were within the control levels. Рhenols content on the black substrate was increased in variants with RBC – by 141 % or with TL – by 184 % relatively to control. The content of H2O2 on the red substrate was reduced – by 11 % with RBC and by 10 % with TL, on the black substrate was within the control. The reducing of phytotoxicity of waste dumps of coal mines after sorghum growth (from highest to middle level) was shown. Obtained results showed the perspectives of application of sorghum and biosurfactants for the phytoremediation of the technogenic affected soils.

The relevance of the research is caused by the need to study the specific character of coal producer dust input effect on pollution of adjacent urban territories. The main aim of the research is to evaluate the dust load level using the computational and experimental techniques in the area of coal producer effect by snow cover survey data. Objects of the research are snow samples taken by the square scheme in the town area and by the vector scheme in directions from the town to coal enterprises. Methods: atmogeochemical, calculation using the model of long-term particle fallout from atmosphere to the surface. Results. Regions with maximum values of dust load are in the area of open cut (459 mg/m2·day) and mine (422 mg/m2·day), by the gradation these values correspond to high level of pollution. High values of dust load (200-245 mg/m2·day) within the limits of the town correspond to location of coal boiler houses with open storage. On the outskirts of central and eastern parts of the town the dust load is additionally formed due to the dust wind transfer from closely located coal plants. The studied areas form the range by the decrease of mean value of dust load level: the south-west direction from town to open-cut coal mine (260±45 mg/m2·day) > the north-east direction from town to coal mine (153±71 mg/m2·day) > the eastern part of the town (131±12 mg/m2·day) > the western part of the town (128±17 mg/m2·day) > the south-west direction from town to tourist camp (30±1 mg/m2·day). Excess ratio of ambient dust load amounts to 24,8; 14,6; 12,5; 12,2; 2,9, respectively, at the studied areas. A part of industrial particles, including coal dust, soot, slags, aluminosilicate micro-spherule, fibers, is maximum in the territory, adjacent to the open-cut coal mine (85 %) and coal mine (88 %), and it is lower within the limits of the town (76-79 %). Content of coal particles, prevailing in all studied samples, changes from 20-23 % in the town to 44-82 % near the coal mine and open-cut coal mine; coal dust input in this case is considerably lower at underground mining than at open-cut coal mine. In the town a part of the particles, distinguishing coal burning (carbon coal), amounts to 33-36 %. The authors have compared the calculated coal dust values with those determined by the experiment. The well-significant correlation ratios for western and eastern parts of the town, the area of open-cut coal mine and tourist camp amounted to 0,66 (11 samples); 0,83 (21 samples); 0,73 (9 samples); 0,76 (6 samples) respectively. The model of the long-term fallout reflects rather well the change in quantitative precipitation indices in the studied territories. The results of modeling may be further used to assess chronic inhalation risks for population health, based on average annual concentrations.

The relevance of the research is caused by the need to study the specific character of coal producer dust input effect on pollution of adjacent urban territories. The main aim of the research is to evaluate the dust load level using the computational and experimental techniques in the area of coal producer effect by snow cover survey data. Objects of the research are snow samples taken by the square scheme in the town area and by the vector scheme in directions from the town to coal enterprises. Methods: atmogeochemical, calculation using the model of long-term particle fallout from atmosphere to the surface. Results. Regions with maximum values of dust load are in the area of open cut (459 mg/m2·day) and mine (422 mg/m2·day), by the gradation these values correspond to high level of pollution. High values of dust load (200-245 mg/m2·day) within the limits of the town correspond to location of coal boiler houses with open storage. On the outskirts of central and eastern parts of the town the dust load is additionally formed due to the dust wind transfer from closely located coal plants. The studied areas form the range by the decrease of mean value of dust load level: the south-west direction from town to open-cut coal mine (260±45 mg/m2·day) > the north-east direction from town to coal mine (153±71 mg/m2·day) > the eastern part of the town (131±12 mg/m2·day) > the western part of the town (128±17 mg/m2·day) > the south-west direction from town to tourist camp (30±1 mg/m2·day). Excess ratio of ambient dust load amounts to 24,8; 14,6; 12,5; 12,2; 2,9, respectively, at the studied areas. A part of industrial particles, including coal dust, soot, slags, aluminosilicate micro-spherule, fibers, is maximum in the territory, adjacent to the open-cut coal mine (85 %) and coal mine (88 %), and it is lower within the limits of the town (76-79 %). Content of coal particles, prevailing in all studied samples, changes from 20-23 % in the town to 44-82 % near the coal mine and open-cut coal mine; coal dust input in this case is considerably lower at underground mining than at open-cut coal mine. In the town a part of the particles, distinguishing coal burning (carbon coal), amounts to 33-36 %. The authors have compared the calculated coal dust values with those determined by the experiment. The well-significant correlation ratios for western and eastern parts of the town, the area of open-cut coal mine and tourist camp amounted to 0,66 (11 samples); 0,83 (21 samples); 0,73 (9 samples); 0,76 (6 samples) respectively. The model of the long-term fallout reflects rather well the change in quantitative precipitation indices in the studied territories. The results of modeling may be further used to assess chronic inhalation risks for population health, based on average annual concentrations.

In the article on the basis of the analysis of practice of coal mining enterprises urgency of improving the concordance persona. In particular, it is shown that the disagreement of the staff is a system limitation of the company’s development. The paper also describes the case of using this tool to improve the concordance of staff as educational certification, and also identifies the cyclical nature of its application. The author’s proposed approach is tested on a number of coal mines in conducting developmental assessments.

In safety sciences, accidents are unintended and non-scheduled events happening as one or more consecutive incidents as a result of unsafe acts or unsafe conditions, or both. Despite growing improvements in safety sciences in recent decades, the concept of accident, as a non-social phenomenon, is defined as neutral and meaningless, which occurs in an unintended and non-scheduled way through workers or machines. A significant amount of the research carried out in this field, following the tradition of epidemiology and behavioral psychology and by reducing the problem of safety and work health to a technical issue, emphasizes the role of individuals’ risk factors and human error in the occurrence of accidents. These studies neglect social, economic, cultural and institutional contexts in the analysis of accidents and take no advantage of interdisciplinary findings, as a result of which such reports only provide a list of risk factors and the statistical distribution of events in terms of quantitative and demographic variables; thus, they disregard the process of the social construction of accidents and the problematic nature of the concept of accidents. Therefore, the present study intends to expose the limitations of safety sciences and its conventional technical approaches in the unilateral and one-dimensional explanation of work-related accidents. For this purpose, in this research, qualitative methodology has been used as the dominant methodology, and critical ethnography has been utilized for the research process, and also thematic analysis has been employed for data analysis. The findings of the study include seven main categories which are shown in the form of the social construction cycle of accidents. Finally, the results show that work-related accidents are mainly due to the conditions governing the organization, unequal power relations and workers’ experiences of work environment than carelessness and the individual and psychological characteristics of workers.

Based on actual production and management situation, this paper investigates an enterprise-level coal mine equipment management system, aiming at solving problems in electrical equipment management in mining companies. The proposed management system fuses the cloud computing framework, the workflow technology and the enterprise asset management (EAM) model. Nine function modules are designed according to the EAM concepts, such as lifecycle management, preventive maintenance, and spot inspection management. A four-layer cloud platform is constructed adopting a three-level cloud service architecture model and two types of cloud deployment. Using a workflow engine to assist in the EAM system, the coal mine equipment management system could flexibly transfer its business processes and effectively manage multi mine equipment at enterprise-level. Take a typical domestic coal mining enterprise as a case, the feasibility and effectiveness of the EAM system of coal mine equipment based on cloud computing and workflow technology is verified.

Current business environment and growing exposure to a wide range of risks require companies (especially the large ones) to raise a question of risk management, start treating it as a particular business function that needs special attention and for which they have to seek proper solutions within their organizational structure. This particularly affects the coal industry, where risk exposure is rather evident and makes risk management one of the key management issues in general. A central point of the analysis includes companies in the coal industry of the Federation of Bosnia and Herzegovina (F BiH), where the management needs to be greatly concerned about protection against risks that affect this industry much more than other industries, in particular pure risks (those that involve only the possibility of loss and no possibility of gain ). And if we add the so - called emerging or “newly developing” risks, which are still unknown even to risk management experts, it is clear that management of large companies have to take care of risk management culture development and seek adequate organizational solutions. On the basis of the conducted empirical research, the paper will show and appropriately explain the descriptive analysis results, accordingly used for establishment of the level of risk management efficiency in the coal mines of the F BiH and identification of certain weaknesses, whose elimination could significantly improve the process and increase the level of economic protection for these companies.

Flooded mine workings have good potential as low-enthalpy geothermal resources, which could be used for heating and cooling purposes, thus making use of the mines long after mining activity itself ceases. It would be useful to estimate the scale of the geothermal potential represented by abandoned and flooded underground mines in Europe. From a few practical considerations, a procedure has been developed for assessing the geothermal energy potential of abandoned underground coal mines, as well as for quantifying the reduction in CO2 emissions associated with using the mines instead of conventional heating/cooling technologies. On this basis the authors have been able to estimate that the geothermal energy available from underground coal mines in Europe is on the order of several thousand megawatts thermal. Although this is a gross value, it can be considered a minimum, which in itself vindicates all efforts to investigate harnessing it.

Underground gravity surveys are usually conducted in order to define geological structures and to locate and delineate ore bodies. In the coal mines, on the other hand, these surveys are often applied in solving stability and safety problems of the mine. Basic principals of underground gravity measurements and examples of application in coal mining are presented. Complex geophysical and geological investigations were conducted in a wider area of the coal mine 'Trbovlje - Hrastnik' (Slovenia) in purpose to define geological features and delineate potentially dangerous zones, connected to the subsidence, rockslides and water penetrations into exploitation galleries of the mine. Gravity and microtremor measurements were conducted in the mine galleries. Compilation and interpretation of subsurface gravity anomaly maps and interval density map is presented.

Іndicators of growing, changes in content of photosynthetic pigments, hydrogen peroxide, and activity of peroxidase in growing plants of colza were studied regarding negative influence of and soil components of rock dumps of coal mines. It was shown that heavy metals possess the most negative influence on the morphological and physiological indicators, and their influence is increasing with elevation of acidity. Decrease in content of hydrogen peroxide and increase in the activity of peroxidase suggests the activity of protective mechanisms in the growing plants of colza.

Сhanges of particle-size distribution substrates rock dumps under thicket of the Calamagrostis epigeios (L) Roth, humus content and pH of substrates are studied. The changes of rock dumps environment at overqrowing with C. epigeios and the possibility of qrowth of other plants on these rock dumps are shown.

Wireless sensor networks deployed in coal mines could help companies provide workers working in coal mines with more qualified working conditions. With the underground information collected by sensor nodes at hand, the underground working conditions could be evaluated more precisely. However, sensor nodes may tend to malfunction due to their limited energy supply. In this paper, we study the cross-layer optimization problem for wireless rechargeable sensor networks implemented in coal mines, of which the energy could be replenished through the newly-brewed wireless energy transfer technique. The main results of this article are two-fold: firstly, we obtain the optimal relay nodes’ placement according to the minimum overall energy consumption criterion through the Lagrange dual problem and KKT conditions; secondly, the optimal strategies for recharging locomotives and wireless sensor networks are acquired by solving a cross-layer optimization problem. The cyclic nature of these strategies is also manifested through simulations in this paper.