1,995 results on '"coal mine"'
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2. Research on the high precision hydraulic column stress monitoring method.
- Author
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Zhang, Jianzhuo, Wan, Chuanxu, Wang, Jie, Chen, Ce, Wang, Tao, and Xu, Kai
- Abstract
The hydraulic column is a core component in the coal mine support system, however, the real-time monitoring of the hydraulic column during the service process of the hydraulic support faces challenges. To address these issues, a high-precision stress mapping method of hydraulic column is proposed. The hydraulic column loss function was constructed to guide the data-driven model training, and the cylinder stress mechanism model was established by using the elastic–plastic theory of thick-walled cylinder. The weight coefficients of the data-driven model and the mechanism model were determined by the measurement data, and the high-precision stress mapping results were obtained by combining the data-driven model data and mechanism model data. A monitoring platform was built for the unit hydraulic support column, and the unit hydraulic support column was used as the test object to carry out pressure tests of 600 kN, 800 kN, 1000 kN and 1200 kN. The test data of the four groups showed that the error between the stress mapping results and the measured value of the strain gauges was 3.086%, 1.783%, 1.182% and 1.548%, respectively. The mapping period is 0.32 s, which proves that the method can provide real-time and high-precision feedback on the stress state of the hydraulic column, realize real-time monitoring of the stress state of the hydraulic column, solve the problem that stress cannot be measured by attaching strain gauges in the complex underground environment, predict the fault and safety problems of the hydraulic column due to overload, and provide data reserve for the adaptive regulation of the hydraulic support. [ABSTRACT FROM AUTHOR] more...
- Published
- 2025
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3. Detection and pose measurement of underground drill pipes based on GA-PointNet++: Detection and pose measurement of underground drill pipes based on GA-PointNet++ : J. Luo et al.
- Author
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Luo, Jiangnan, Cai, Jinyu, Li, Jianping, Zhang, Deyi, Gao, Jiuhua, Li, Yuze, Lei, Liu, and Hao, Mengda
- Abstract
Drilling for gas extraction, a common method in coal mine gas control, involves tedious loading and uploading of drill pipes. This study aims to design a method for detecting and measuring pose drill pipes using point cloud data. We present an experimental platform for acquiring drill pipe point cloud data under various lights. Additionally, we propose a GA-PointNet + + model, enhanced with an adversarial generation network. The pose of the drill pipe was calculated from the segmented pipe and pin point clouds. Results indicate that the intersection-over-union (IoU) values for pipe and pin, based on GA-PointNet + + , are 0.824 and 0.472, respectively. Evaluating the model's performance in recognizing the pin using the ROC curve yielded an AUC of 0.87. The combination of GA-Pointnet + + and RGB-D camera was used to pose drill pipes, achieving an average accuracy of 82.5% under different lighting conditions. Under lighting conditions of 25–35 lx with an added diffuser film and 10–15 lx, the accuracy reaches 90%, with average distance errors of 1.4 cm and 2.5 cm, and average angle errors of 3.5° and 3.7°, respectively. This has significant implications for the use of LED lights in underground environments. Therefore, the proposed drill pipe pose measurement method is of great significance for the intelligentization of coal mine drilling operations. [ABSTRACT FROM AUTHOR] more...
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- 2025
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4. Dust concentration distribution and analysis of influencing factors in the heading face of Shangwan coal mine.
- Author
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Li, Yufu, Wang, Jie, Li, Zhibin, and Mo, Haitao
- Subjects
COAL dust ,DUST control ,DUST removal ,TWO-phase flow ,COAL mining ,GAS distribution ,MINE ventilation - Abstract
Dust concentration in coal mine roadways significantly affects worker safety and health. Effective dust control is critical for optimizing the mine ventilation system and creating a safer working environment. This study investigates the impact of ventilation duct arrangements on dust concentration in a heading face, aiming to identify the optimal configurations for minimizing dust levels and enhancing worker safety. Using numerical simulations based on the gas-solid two-phase flow model in Fluent, we analyzed the effects of varying duct outlet distances and heights on airflow patterns and dust dispersion. Mesh generation, grid independence verification, and detailed parameter settings ensured accuracy and reliability of the simulation results. Results indicate that positioning the duct outlet 8 m from the heading face reduces dust concentration to approximately 39 mg/m³, while setting the duct height at 1.5 m notably decreases dust levels in the worker breathing zone. A mesh density of 576,449 cells ensured convergence and computational efficiency with an error margin within 2%. The findings provide practical insights into ventilation system optimization for coal mine heading faces, contributing to improved occupational health and operational safety. Future research should focus on validating these results through field experiments and addressing complex real-world conditions. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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5. MIRA-ChatGLM: A Fine-Tuned Large Language Model for Intelligent Risk Assessment in Coal Mining.
- Author
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Sun, Yi, Zhang, Chao, Wang, Chen, and Han, Ying
- Abstract
Intelligent mining risk assessment (MIRA) is a vital approach for enhancing safety and operational efficiency in mining. In this study, we introduce MIRA-ChatGLM, which leverages pre-trained large language models (LLMs) for the domain of gas risk assessment in coal mines. We meticulously constructed a dataset specifically designed for mining risk analysis and performed parameter-efficient fine-tuning on the locally deployed GLM-4-9B-chat base model to develop MIRA-ChatGLM. By utilizing consumer-grade GPUs and employing LoRA and various levels of quantization algorithms such as QLoRA, we investigated the impact of different data scales and instruction settings on model performance. The evaluation results show that MIRA-ChatGLM achieved excellent performance with BLEU-4, ROUGE-1, ROUGE-2, and ROUGE-L scores of 84.47, 90.63, 86.88, and 90.63, respectively, highlighting its outstanding performance in coal mine gas risk assessment. Through comparative experiments with other large language models of similar size and manual evaluation, MIRA-ChatGLM demonstrated superior performance across multiple key metrics, fully demonstrating its tremendous potential in intelligent mine risk assessment and decision support. [ABSTRACT FROM AUTHOR] more...
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- 2024
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6. Cognitive Response of Underground Car Driver Observed by Brain EEG Signals.
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Zhang, Yizhe, Guo, Lunfeng, You, Xiusong, Miao, Bing, and Li, Yunwang
- Abstract
In auxiliary transportation within mines, accurately assessing the cognitive and response states of drivers is vital for ensuring safety and operational efficiency. This study investigates the effects of various vehicle interaction stimuli on the electroencephalography (EEG) signals of mine transport vehicle drivers, analyzing the cognitive and response states of drivers under different conditions to evaluate their impact on safety performance. Through experimental design, we simulate multiple scenarios encountered in real operations, including interactions with dynamic and static vehicles, personnel, and warning signs. EEG technology records brain signals during these scenarios, and data analysis reveals changes in the cognitive states and responses of drivers to different stimuli. The results indicate significant variations in EEG signals with interactions involving dynamic and static vehicles, personnel, and warning signs, reflecting shifts in the cognitive and response states of drivers. Additionally, the study examines the overall impact of different interaction objects and environments. The detailed analysis of EEG signals in different scenarios sheds light on changes in perception, attention, and responses related to drivers, which is critical for advancing safety and sustainability in mining operations. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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7. Mechanical Failure Characteristics and Energy Dissipation Laws of the Coal–Concrete Combination under Impact Rates.
- Author
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Xu, Chao, Ma, Shixiang, Wang, Kai, Cao, Zhiguo, Zhang, Yong, and Xi, Hongchuan
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MINES & mineral resources , *STRESS concentration , *STRUCTURAL engineering , *IMPACT loads , *STRAIN rate - Abstract
Mining shallow coal seams and deep coal seams is obviously different. In the deep environment of a coal mine, the stress concentration degree is high, and the dynamic load with impact tendency is prominent. In the practice of underground mining engineering in coal mines, the common coal–concrete combination structure has different degrees of damage and failure under the continuous action of dynamic load at different impact rates, which in turn affects the overall stability of the engineering structure. Therefore, it is of great significance to study the mechanical failure characteristics and energy dissipation law of coal–concrete combinations under the influence of impact rate. In this paper, the split Hopkinson pressure bar (SHPB) dynamic load test system is selected, and coal–concrete combination samples are taken as the impact compression test object. Comparative tests under different impact rates are carried out, and the experimental results of the mechanical parameters of the sample change with the impact rate are obtained. Fractal theory and energy dissipation theory are introduced to study the macroscopic failure characteristics of the combination sample after impact dynamic load and the energy dissipation law during the impact process. The results show that the sample has a strong strain rate correlation, and its dynamic compressive strength, dynamic elastic modulus, and impact rate also have a strong positive correlation. The dynamic stress–strain curve conforms to the four typical stages of the dynamic stress–strain curve. The degree of fragmentation of the sample is proportional to the impact rate. The larger the impact rate, the smaller the proportion of large particle size to small particle size; the fractal dimension of particle size also increases with the impact rate. The transmitted energy, reflected energy, dissipated energy, and incident energy increase with the impact rate, but the increase amplitude is different. The overall energy value is reflected energy > transmission energy > dissipated energy. The energy ratio of different forms fluctuates with the impact rate, the reflected energy ratio is positively correlated with a certain impact rate, the transmission energy ratio is basically symmetric and fluctuates between 30% and 40%, and the dissipated energy ratio increases with the impact rate. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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8. Magnetic–Thermal Coupling-Based Study on the Temperature Characteristics of Flameproof Cable Boxes for Coal Mines at Various Failure Modes.
- Author
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Zhang, Hongkui, Cui, Zhaoxuan, and Lan, Yipeng
- Abstract
Temperature monitoring is the main indicator to ensure the safe operation of the coal mine explosion-proof box. In this study, a three-way flameproof cable box was considered for coal mines. A three-dimensional transient temperature field simulation model was constructed for magnetic–thermal coupling and subsequently used to conduct temperature field simulation for the failure of the flameproof cable box for coal mines. An experimental platform was developed to test the temperature characteristics of failure flameproof cable boxes for coal mines and obtain temperature curves at various failure currents. Using the experimental results of temperature characteristics and temperature field simulation outcomes, we analyzed the time responses and spatial distribution characteristics of the temperature rise of flameproof cable boxes for coal mines. The error between simulation and experimental results does not exceed 1 K, and the upper limit of time to ensure safe operation under different failure modes is determined. Thus, the acquired temperature distribution characteristics in a failure mode can be used as a reference for the design, inspection, and status warning of flameproof cable boxes for coal mines. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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9. Prediction of Floor Failure Depth in Coal Mines: A Case Study of Xutuan Mine, China.
- Author
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Feng, Yu, Bi, Yaoshan, and Li, Dong
- Subjects
WATER damage ,ENVIRONMENTAL protection ,PRINCIPAL components analysis ,SYSTEM failures ,KERNEL functions - Abstract
Accurately predicting the failure depth of coal seam floors is crucial for preventing water damage, ensuring the safe and efficient mining of coal seams, and protecting the ecological environment of mining areas. In order to improve the prediction accuracy of the coal seam floor failure depth, an improved support vector regression (SVR) model is proposed to predict the floor failure depth by taking the 3234 working face in Xutuan Mine as an example. This improved model incorporates principal component analysis (PCA) and slime mould algorithm (SMA) optimization techniques. First, based on the measured data of seam floor failure depth in several mining areas, a prediction index system of floor failure depth was constructed. Subsequently, the PCA method was used to reduce the dimension of the measured data of the coal seam floor failure depth, and the input structure of the SVR model was optimized. Then, the SMA was used to optimize the key parameters, namely the penalty factor (C) and kernel function parameter (g), in the SVR model, achieving automatic parameter selection and obtaining the optimal parameter combination. This process led to the establishment of a coal seam floor failure depth prediction model based on PCA-SMA-SVR. The predictive performance of the PCA-SMA-SVR model, SMA-SVR model, and SVR model was quantitatively evaluated and compared using four quantitative indicators, and the results showed that the PCA-SMA-SVR model had the smallest MAE, RMSE, MRE, and TIC values, which were 1.0470 m, 1.2928 m, 0.0628, and 0.0374, respectively. Finally, the PCA-SMA-SVR model was used to predict that the floor failure depth of the 3234 working face in Xutun Mine was 17.09 m, and the predicted result was compared and analyzed with the results of four commonly used empirical formulas (16.03–21.74 m). The results show that the model is close to the results of four commonly used empirical formulas, indicating that the model has high predictive performance and good practicality. This study is of great significance for the safety, green mining, and ecological environment protection of coal mines. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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10. Methane mitigation potentials and related costs of China's coal mines.
- Author
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Yating Kang, Peipei Tian, Jiashuo Li, Hetong Wang, and Kuishuang Feng
- Subjects
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CLIMATE change mitigation , *ABANDONED mines , *ABATEMENT (Atmospheric chemistry) , *GLOBAL warming , *PRICE increases , *COAL - Abstract
Mitigating methane (CH4) emissions from China's coal mines as the largest contributor to anthropogenic CH4 emissions is vital for limiting global warming. However, the knowledge about CH4 mitigation potentials and economic costs of Chinese coal mines remain poorly understood, which hinders the formulation of tailored CH4 mitigation strategies. Here, we estimate and project China's provincial coal mine methane (CMM) emissions, mitigation potentials and costs under various coal production scenarios, by integrating the dynamic emission factors of CMM and key abatement technologies. We find that through continuous coal cuts and available CMM mitigation measures, China's CMM emissions can be reduced by 65%-78% (10.9 Tg-13.1 Tg) in 2060, compared with the 2021 level. CH4 emissions from abandoned coal mines will far exceed those from coal mining under the 2060 carbon-neutral scenario, especially in northeastern China. It was also found that CMM mitigation is not economically feasible at present, but may be the most cost-effective solution as CO2 prices increase. All coalproducing provinces can achieve CMM mitigation below 50 RMB/t CO2 e in 2060. Inner Mongolia is identified as a hotspot for CMM mitigation with huge potential and lower cost. Our prospective assessment can provide insights into China's CMM mitigation in response to climate change. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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11. Reduced-Order Model of Coal Seam Gas Extraction Pressure Distribution Based on Deep Neural Networks and Convolutional Autoencoders.
- Author
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Hao, Tianxuan, Zhao, Lizhen, Du, Yang, Tang, Yiju, Li, Fan, Wang, Zehua, and Li, Xu
- Subjects
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ARTIFICIAL neural networks , *GAS well drilling , *COALBED methane , *GAS extraction , *REDUCED-order models - Abstract
There has been extensive research on the partial differential equations governing the theory of gas flow in coal mines. However, the traditional Proper Orthogonal Decomposition–Radial Basis Function (POD-RBF) reduced-order algorithm requires significant computational resources and is inefficient when calculating high-dimensional data for coal mine gas pressure fields. To achieve the rapid computation of gas extraction pressure fields, this paper proposes a model reduction method based on deep neural networks (DNNs) and convolutional autoencoders (CAEs). The CAE is used to compress and reconstruct full-order numerical solutions for coal mine gas extraction, while the DNN is employed to establish the nonlinear mapping between the physical parameters of gas extraction and the latent space parameters of the reduced-order model. The DNN-CAE model is applied to the reduced-order modeling of gas extraction flow–solid coupling mathematical models in coal mines. A full-order model pressure field numerical dataset for gas extraction was constructed, and optimal hyperparameters for the pressure field reconstruction model and latent space parameter prediction model were determined through hyperparameter testing. The performance of the DNN-CAE model order reduction algorithm was compared to the POD-RBF model order reduction algorithm. The results indicate that the DNN-CAE method has certain advantages over the traditional POD-RBF method in terms of pressure field reconstruction accuracy, overall structure retention, extremum capture, and computational efficiency. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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12. Monitoring Aeolian Erosion from Surface Coal Mines in the Mongolian Gobi Using InSAR Time Series Analysis.
- Author
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Kim, Jungrack, Amgalan, Bayasgalan, and Bulkhbai, Amanjol
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COAL mining , *TIME series analysis , *SYNTHETIC aperture radar , *EOLIAN processes , *REMOTE sensing , *COAL dust - Abstract
Surface mining in the southeastern Gobi Desert has significant environmental impacts, primarily due to the creation of large coal piles that are highly susceptible to aeolian processes. Using spaceborne remote sensing and numerical simulations, we investigated erosional processes and their environmental impacts. Our primary tool was Interferometric Synthetic Aperture Radar (InSAR) data from Sentinel-1 imagery collected between 2017 and 2022. We analyzed these data using phase angle information from the Small Baseline InSAR time series framework. The time series analyses revealed intensive aeolian erosion in the coal piles, represented as thin deformation patterns along the potential pathways of aerodynamic transportation. Further analysis of multispectral data, combined with correlations between wind patterns and trajectory simulations, highlighted the detrimental impact of coal dust on the surrounding environment and the mechanism of aeolian erosion. The lack of mitigation measures, such as water spray, appeared to exacerbate erosion and dust generation. This study demonstrates the feasibility of using publicly available remote sensing data to monitor coal mining activities and their environmental hazards. Our findings contribute to a better understanding of coal dust generation processes in surface mining operations as well as the aeolian erosion mechanism in desert environments. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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13. Study on the Identification Method of Planar Geological Structures in Coal Mines Using Ground-Penetrating Radar.
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Liu, Jialin, Tang, Xiaosong, Yang, Feng, Qiao, Xu, Li, Fanruo, Peng, Suping, Huang, Xinxin, Fang, Yuanjin, and Xu, Maoxuan
- Subjects
- *
MINES & mineral resources , *COAL mining , *ANTENNAS (Electronics) , *RADAR , *GROUND penetrating radar , *SIGNALS & signaling - Abstract
The underground detection environment in coal mines is complex, with numerous interference sources. Traditional ground-penetrating radar (GPR) methods suffer from limited detection range, high noise levels, and weak deep signals, making it extremely difficult to accurately identify geological structures without stable feature feedback. During research, it was found that the detection energy of the same target significantly changes with the antenna direction. Based on this phenomenon, this paper proposes a geological radar advanced detection method using spatial scanning. This method overcomes constraints imposed by the underground coal mine environment on detection equipment, enhancing both detection range and accuracy compared to traditional approaches. Experiments using this method revealed pea-shaped response characteristics of planar geological structures in radar images, and the mechanisms behind their formation were analyzed. Additionally, this paper studied the changes in response characteristics under changes in target inclination, providing a basis for understanding the spatial distribution of geological structures. Finally, application experiments in underground coal mine environments explored the practical potential of this method. Results indicate that, compared to drilling data, this method achieves identification accuracies of 91.88%, 90.42%, and 78.72% for the depth and spatial extent of geological structures, providing effective technical support for coal mining operations. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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14. ActiveGCN-CT: Active Learning-Enhanced Graph Convolutional Networks for Computed Tomography Inversion in Coal Mines.
- Author
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Zhan, Kai, Wen, Xiaotao, Zhang, Lianhai, and Wang, Xuben
- Subjects
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SEISMIC wave velocity , *COAL mining safety , *SEISMIC networks , *COMPUTED tomography , *SENSOR networks - Abstract
In the realm of coal mine safety, accurately detecting high-stress regions within the coal seam at the working face is paramount for averting rockburst incidents and boosting mining efficiency. This paper introduces ActiveGCN-CT, a novel graph convolutional network (GCN) model enriched with an active learning strategy, tailored for active source computational tomography (CT) inversion in coal mines. The research shows that the magnitude of stress in coal bodies is generally positively correlated with P-wave velocities; hence, precise P-wave velocity imaging can effectively pinpoint high-stress zones. In comparison to traditional CT inversion techniques and current deep learning tomography methods, ActiveGCN-CT delivers accurate P-wave velocity imaging even under conditions of sparse sensor networks and limited active seismic sources. By utilizing actual data from a coal mining face in China, our model employs an active learning strategy to efficiently select samples for training. This significantly improves the accuracy of seismic wave velocity model predictions and drastically reduces the number of training samples and iterations needed. Through comparisons with the SIRT algorithm and verification experiments conducted at coal mine sites, the effectiveness of the ActiveGCN-CT model in effectively identifying high-stress areas is confirmed, providing a new technical approach for the safety monitoring and management of coal mines. Highlights: Developed ActiveGCN-CT, a novel graph convolutional network model that integrates active learning for P-wave velocity imaging in coal mines. Demonstrated superior accuracy of ActiveGCN-CT over traditional CT inversion techniques and other deep learning methods under conditions of sparse sensor networks and limited seismic sources. Introduced an innovative approach to address non-uniqueness and sensitivity issues in seismic data, significantly reducing prediction ambiguity in high-stress zones. Validated the model with actual coal mine data, illustrating its potential to significantly improve safety and efficiency in mining operations. Proved the model's effectiveness in rapidly identifying high-stress areas, thereby facilitating timely preventive measures against rockbursts. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
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15. Evaluation method integrating game theory and cloud modelling for coal mine emergency management capacity.
- Author
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Yuansheng Wang, Shaoshuai Guo, and Jingxuan Zhu
- Subjects
COAL mining ,GAS bursts ,EMERGENCY management ,COAL gas ,GAME theory ,COAL mining accidents - Abstract
Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...
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- 2024
- Full Text
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16. A Combined Method Utilizing Microseismic and Parallel Electrical Monitoring to Determine the Height of Water-Conducting Fracture Zones in Shengfu Coal Mine.
- Author
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Luo, Bin, Zhang, Chenghang, Zhang, Peng, Huo, Jiayi, and Liu, Shengdong
- Subjects
WATER seepage ,FAULT zones ,COAL mining ,ELECTRIC transients ,ELECTRIC fields - Abstract
The development of a water-conducting fracture zone is a critical factor in understanding and predicting water inrush from coal mine roofs, as these zones facilitate the inflow of water from overlying aquifers. However, traditional methods such as empirical formulas and drilling, as well as single physical investigations (such as transient electromagnetic), can only estimate the height of these fault zones and often cannot accurately obtain precursor information of roof water inrush during the mining process. In this study, a comprehensive evaluation of the 13,101 working face of the Shengfu Coal Mine in Shaanxi, China, is being carried out using microseismic monitoring and parallel electrical methods. On the basis of the microseismic results, the height of the water-conducting fracture zone is obtained to be 57 m. The average variation of the natural potential of the coal seam roof was obtained by the parallel electric method, which was all less than 250 mV, with no obvious anomalous seepage electric field and no large centralized water-conducting channels found. However, the decrease in resistivity and natural potential indicates the precursor information of water seepage when the fracture zone develops to 40–50 m. This approach aims to monitor the development of water-conducting fracture zones by combining microseismic monitoring with parallel electrical methods while simultaneously capturing changes in roof seepage. This will enhance safety and facilitate more informed decision-making in complex hydrogeological environments. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
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17. 定向长钻孔瓦斯抽采负压变化规律及监测控制技术 研究进展.
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李泉新, 程卓尔, 方 俊, 牟全斌, 刘 飞, and 丛 琳
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INTELLIGENT control systems ,AUTOMATIC control systems ,UNDERGROUND pipelines ,GAS engineering ,INTELLIGENCE levels - Abstract
Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...
- Published
- 2024
- Full Text
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18. The Applicability and Reflection Characteristics of Coal Failure Events for External Monitoring-While-Drilling of Underground Pressure Relief Drilling.
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Zhang, Wenlong, Ren, Jianju, Wang, Yongqian, Li, Chen, Zhang, Yingchao, and Teng, Shibin
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ROCK bursts ,COAL mining ,FRACTAL dimensions ,SPECTRUM analysis ,ON-site evaluation - Abstract
Previous research results preliminarily indicated that the Coal Failure Events (CFEs) that occurred during the process of Underground Pressure Relief Drilling (UPRD) represented the phenomenon of coal fracture and energy release. The research results had excellent value for the monitoring and response of pressure relief drilling while drilling, but there were still some special situations that needed to be analyzed and studied in actual on-site testing. So, through on-site testing and data statistical analysis, the study investigated the applicability of the innovative external Monitoring-While-Drilling (MWD) method for UPRD with more coal failure events and made a quantitative statistic of the CFEs and their relationship with abutment pressure to reveal the applicability of the external MWD method and characteristic of CFEs. The results showed that hundreds of CFEs were produced in the UPRD process, which must be removed to ensure the accuracy of the MWD method. Although CFEs bring recognition difficulties, they also provide conditions for studying their own distribution and characteristics. Results showed that more CFEs were produced in the depth of difficult drilling, which indicated that there was a positive correlation between the degree of difficulty in drilling and the number of CFEs. In addition, spectrum analysis showed that the depths with more CFE occurrence were more likely to produce high-frequency events. When the surrounding stress of drilling rocks is high, the occurrence of small fractures with a higher main frequency may become more frequent and consistent; more fractures with similar failure forms would occur, which may have a lower fractal dimension and promote the generation of more failure. The research results were of great significance for the MWD method for UPRD, a quantitative study of CFEs and their generation characteristics during UPRD construction. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
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19. 闭坑煤矿山酸性废水治理方法:以贵州省 道真县平模山闭坑煤矿为例.
- Author
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陈鸿申, 赵 爽, 田合利, 龚芯磊, and 陈忠发
- Subjects
COAL mining ,WASTEWATER treatment ,WATER purification ,SEWAGE purification ,GROUNDWATER recharge - Abstract
Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...
- Published
- 2024
- Full Text
- View/download PDF
20. Visual analysis of coal mine safety using CiteSpace V
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Xuesen Zhang and Li Yang
- Subjects
CiteSpace V ,CNKI ,coal mine ,safety evaluation ,Technology ,Science - Abstract
Abstract To intuitively and systematically grasp the development status and trend of safety evaluation research in China's coal mining operations, we consulted relevant literature in the fields of “coal mine” and “safety evaluation” collected by China Knowledge Network, and deployed CiteSpace V software to summarize and analyze research pertaining to safety evaluation in China's coal mines from three aspects: research institutions, authors, and hot keywords. With respect to research institutions, the results show that although many researchers have conducted in‐depth evaluations of coal mine safety, most of these studies were independent, and two‐way information exchange and cooperation between research institutions remains scarce. With respect to authors, most cooperation between authors has been limited to team members, and relatively stable research teams have been formed. However, most of these research teams are independent. With respect to hot keywords, the trends of coal mine safety evaluation studies exhibit continuous change, with an overall increase in richness. According to the frequency burst times of important keywords, “entropy weight method” and “mining with pressure” are expected to remain important keywords in future evaluations of coal mine safety in China. more...
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- 2024
- Full Text
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21. Model of environmental management due to coal mining on the Separi River in Tenggarong Seberang District, Kutai Kartanegara Regency, East Kalimantan Province
- Author
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Nur Efendi, Eri Barlian, Nur Hasan Syah, Indang Dewata, Dian Adhetya Arif, and Iswandi Umar
- Subjects
coal mine ,environment ,ism method ,sustainability ,water quality ,Environmental effects of industries and plants ,TD194-195 - Abstract
Coal mining has a significant impact on reducing river water quality. The decline in river water quality causes problems for human life and the environment. Therefore, this research aimed to evaluate river water quality and develop strategies for improving river water quality due to open pit coal mining activities in Tenggarong Seberang District and develop environmental improvement strategies. Several chemical parameters, including pH, TSS, Fe, and Mn, were observed through laboratory tests to determine water quality in the Separi River used in coal mining. The next step was determining environmental improvement strategies using the ISM approach. Twenty stakeholders from related agencies and institutions using FGD were involved in developing a policy strategy. The results of the analysis showed that there has been a decrease in river water quality standards due to mining activities in the research area, and the quality is still below the standard quality. Therefore, two significant strategies must be a priority for the environmental management of the Separi River. First, Conducting an environmental audit of the factors causing the decline in river water quality is necessary. Second, there must be warnings and legal sanctions for negligence in oil spills and oil used from coal mining. more...
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- 2024
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22. Assessment of readiness of auxiliary mine rescue teams in coal mines
- Author
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V. A. Rudenko
- Subjects
militarized mine rescue units ,auxiliary mine rescue team ,coal mine ,safety ,accident ,expert assessment ,tactical exercises ,Mining engineering. Metallurgy ,TN1-997 - Abstract
The efficiency of mine rescue operations largely depends on how quickly efforts to localize and mitigate an accident are initiated. Given the remoteness of some mining enterprises, a decision was made to form auxiliary mine rescue teams composed of miners. However, there is ongoing debate regarding the effectiveness of the rescue operations carried out by these auxiliary teams. This paper presents data on the assessment of the readiness of auxiliary mine rescue teams in Russian coal mines. A survey of professional mine rescuers was conducted across all units and platoons, focusing on key aspects of auxiliary team operations. The results, based on expert evaluations, revealed the main challenges in training auxiliary team members and highlighted areas for improving the regulatory and methodological framework for mine rescue tactics. The second part of the paper presents the results of control-tactical exercises held at seven mines. These unannounced exercises took place at the end of a work shift and evaluated a wide range of knowledge, skills, abilities, and physical fitness among the auxiliary teams. Key evaluations included the accuracy of task allocation, tactical training, preparation for mine descent, the use of rescue equipment, first aid skills, theoretical knowledge, and physical fitness. more...
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- 2024
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23. Mapping the spatial distribution of air pollutants in Quang Ninh province (Vietnam) using Sentinel 5P data
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Le Hung Trinh, Van Phu Le, Thi Hanh Tong, and Sinh Dinh Mai
- Subjects
air pollutants ,remote sensing ,coal mine ,sentinel 5p tropomi ,quang ninh province ,vietnam ,Geodesy ,QB275-343 - Abstract
Vietnam is a country with rich mineral resources, of which coal reserves are about 8.6 billion tons, concentrated mainly in the coal basin of Quang Ninh province. Besides the economic and social benefits, coal mining has negative impacts on the environment, such as air and water pollution. Air pollution in coal mining areas seriously affects human health and the environment. This study presents the results of mapping the quarterly spatial distribution maps of air pollutants in Quang Ninh province, including CO, NO2, O3 and SO2 from Sentinel 5P TROPOMI data. Sentinel 5P TROPOMI data on four air pollutant concentrations in the entire year 2023 was collected using the Google Earth Engine (GEE) cloud computing platform and then averaged over the quarters. The results of air pollution assessment from remote sensing data are compared with the limit values of basic parameters in the air in QCVN 05:2013/BTNMT National technical regulation on air quality. Analysis of the achieved results show that the concentrations of CO, NO2, O3 and SO2 in Quang Ninh province in 2023 are all high compared to regulations in QCVN, especially in the southern region where large coal mines are concentrated. The results received in this study provide timely information to help managers monitor air quality in coal mining areas. more...
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- 2024
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24. CFD MODELLING OF THE DUST AND AIR VELOCITY BEHAVIOUR AT AN UNDERGROUND COAL MINE ROADWAY
- Author
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Gülnaz Daloğlu
- Subjects
respirable dust ,air velocity ,cfd modeling ,coal mine ,mine safety ,solunabilir toz ,hava hızı ,cfd modelleme ,kömür madeni ,maden emniyeti ,Engineering (General). Civil engineering (General) ,TA1-2040 - Abstract
Dust pollution for ventilation systems is a big problem for mine workers in underground coal mines. The respirable dust concentration is important to the physical and spiritual health of miners. It is hazardous up to 2 mg/m3in the air in underground coal galleries. In the present work, the airflow velocity and dust concentration values were measured at Çay 1-Kartiye roadway in Kozlu, Zonguldak. The goal of this research is modelling to the dust concentration and airflow velocity values by the computational fluid dynamics (CFD) method. An airflow and dust fluid and solid model was done using the Eularian-Granular multiphase method with the k-epsilon two-equation model. The results showed that dust concentration values were too low and fixed. The error percentage of airflow velocity values changed between 5% and 17%. Thus, this roadway is safe for coal dust explorations. more...
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- 2024
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25. Dynamic correlation between surface carbon response and underlying emissions from spontaneous combustion goaf: field study of an abandoned coal mine
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Yongjun Wang, Qian Zheng, Hemeng Zhang, Xiaoming Zhang, Wei Dong, Yuichi Sugai, and Kyuro Sasaki
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CO2 flux ,Goaf ,Gas emission ,Coal mine ,Spontaneous combustion ,Environmental pollution ,Geophysics. Cosmic physics ,QC801-809 - Abstract
Abstract Abandoned coal mine goaf is affected by air leakages and prone to spontaneous combustion, resulting in environmental pollution and geological disasters. Haizhou Open-pit Mine adopts both underground and open-pit mining methods. During the long-term mining process, the original stable stratum structure is constantly destroyed, and the slope slides, increasing cracks and severe air leakage around the goaf and roadway. The spontaneous combustion of coal is particularly prominent after the mine shut down. At present, there is no suitable indirect monitoring method to effectively explore the spontaneous combustion area in goaf. The study developed an all-weather monitoring plan and conducted multi-point continuous long-term measurements of the spontaneous combustion state in one abandoned coal mine goaf located in the eastern part of the Haizhou Open-pit Mine. We evaluated the dynamic correlation between surface CO2 flux (SCF) and changes in the underground fire areas, determined the scope and evolution trend of the fire areas, and identified the distribution and change laws of SCF. The results show a significant positive correlation between SCF and soil temperature; moreover, the SCF value was found to reflect the CO2 emission intensity of the goaf. The high SCF in the test area showed month-wise expansion and increase, while the CO2 emission gradually increased monthly, and the calculated annual total emission was approximately 7017 t. Hence, the study can further provide guidance for the monitoring of spontaneous combustion in shallow coal seams, goaf and the assessment of CO2 emissions from underground coal fires through the on-site monitoring and analysis results. more...
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- 2024
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26. Valorisation of acid mine drainage through effective recovery of selected rare earth elements using cationic resins.
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Ntumba, Nsaka Christophe, Maree, Jannie Philippus, and Ngole-Jeme, Veronica
- Subjects
- *
INDUCTIVELY coupled plasma atomic emission spectrometry , *ACID mine drainage , *MINE drainage , *GOLD mining , *COAL mining - Abstract
Acid mine drainage (AMD) presents a challenge to the environment if not well managed, but it also presents an opportunity for the recovery of economically valuable products, including rare earth elements (REEs), which are critical for the development of advanced, and green technologies. REE concentrations in AMD samples from coal and gold mines were determined using inductively coupled plasma optical emission spectroscopy (ICP-OES) and their sorption by different cationic resins (CHT4083, CHP4502 and CHP00712) was evaluated. Optimum conditions for the sorption of the REEs by these resins were determined through batch experiments and desorption of the REEs from the resins using different concentrations of sulphuric acid (H2SO4) solutions. Coal mine drainage (CMD), with a low pH of 2.37, had higher amounts of REEs (ΣREE 226.3732 mg/L) than AMD from the gold mines (ΣREE 4.9705 mg/L), with a pH of 3.21. A REE sorption efficiency of up to 98% was obtained with CHP4502 and CHP00712 resins and further optimisation of CHP00712 revealed that a resin volume of 250 mL and a contact time of 10 min were required to successfully remove REEs from 500 mL AMD. The sorption capacities of the resin for the selected REEs were 3.88 mg/g, 0.88 mg/g, 1.37 mg/g, 3.18 mg/g, 0.67 mg/g, 0.01 mg/g and 0.27mg/g for Pr, Gd, Nd, Ce, Sm, Eu and Y, respectively. Elution of the resin with a 0.5 N solution of sulphuric acid desorbed the REEs. AMD from coal mines could be an alternate source of REEs and cationic resins can be used to recover these REEs from the CMD. Further investigations, including impregnation of resin to improve its sorption capacity, and temperature effects on the sorption process, are recommended. [ABSTRACT FROM AUTHOR] more...
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- 2024
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27. Visual analysis of coal mine safety using CiteSpace V.
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Zhang, Xuesen and Yang, Li
- Subjects
- *
COAL mining safety , *COAL mining , *RESEARCH teams , *RESEARCH personnel , *INFORMATION sharing - Abstract
To intuitively and systematically grasp the development status and trend of safety evaluation research in China's coal mining operations, we consulted relevant literature in the fields of "coal mine" and "safety evaluation" collected by China Knowledge Network, and deployed CiteSpace V software to summarize and analyze research pertaining to safety evaluation in China's coal mines from three aspects: research institutions, authors, and hot keywords. With respect to research institutions, the results show that although many researchers have conducted in‐depth evaluations of coal mine safety, most of these studies were independent, and two‐way information exchange and cooperation between research institutions remains scarce. With respect to authors, most cooperation between authors has been limited to team members, and relatively stable research teams have been formed. However, most of these research teams are independent. With respect to hot keywords, the trends of coal mine safety evaluation studies exhibit continuous change, with an overall increase in richness. According to the frequency burst times of important keywords, "entropy weight method" and "mining with pressure" are expected to remain important keywords in future evaluations of coal mine safety in China. [ABSTRACT FROM AUTHOR] more...
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- 2024
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28. 煤矿巷道空间毫米波雷达测量特性与重建方法.
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薛旭升, 杨星云, 岳佳宁, 王川伟, 毛清华, 马宏伟, and 王荣泉
- Subjects
COAL mining ,MILLIMETER waves ,GEOLOGICAL modeling ,SURFACE reconstruction ,POINT cloud - Abstract
Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...
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- 2024
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29. Soil organic carbon and nitrogen in a carboniferous spoil heap as a function of vegetation type and reclamation treatment.
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Misebo, Amisalu Milkias, Woś, Bartłomiej, Sierka, Edyta, and Pietrzykowski, Marcin
- Subjects
SPOIL banks ,MINE soils ,COAL mining ,TOPSOIL ,SOIL sampling - Abstract
Evaluating the impact of vegetation types and reclamation methods on soil organic carbon and nitrogen in carboniferous spoil heaps is critical for selecting the best vegetation type and reclamation method to improve ecosystem services in a changing climate. This paper presents the relationship between vegetation types (woodland, forbland, and grassland) and reclamation techniques (barren rock, topsoil application, succession, and cultivation) on soil organic carbon (SOC) and total nitrogen (TN) in developing soils on carboniferous rocks in coal mine heaps. Soil samples were collected from the litter layer (Oi + Oe) and the A horizons (0–10 cm). The results revealed that vegetation types and reclamation methods significantly affected SOC and TN stocks. Woodland exhibited higher SOC and TN in the Oi + Oe horizons than other vegetation types. Topsoil application and cultivation resulted in the highest SOC and TN stocks in the A horizons (0–10 cm) under woodland and forbland compared to succession on bare carboniferous rock. In grassland, there was no significant difference in SOC stock under topsoil application and cultivation; however, significantly higher TN stock was observed in the 0–10 cm areas with topsoil application compared to succession on bare carboniferous rock. Based on the results, topsoil application is recommended to improve SOC if the mining site is restored using woodland. Conversely, grassland exhibits a similar amount of SOC stock with or without topsoil application. Considering the difficulty of obtaining topsoil, we suggest that grasses are optimal for SOC stock in the studied mining sites, followed by forbs. [ABSTRACT FROM AUTHOR] more...
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- 2024
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30. Neuro-fuzzy prediction model of occupational injuries in mining.
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Ivaz, Jelena S., Petrović, Dejan V., Stojadinović, Saša S., Stojković, Pavle Z., Petrović, Sanja J., and Zlatanović, Dragan M.
- Subjects
- *
MINES & mineral resources , *FUZZY neural networks , *COAL mining , *WORK-related injuries , *WELL-being - Abstract
Objectives. This study investigates the possibility of developing a unique model for predicting work-related injuries in Serbian underground coal mines using neural networks and fuzzy logic theory. Accidents are common due to the unique nature of underground mineral extraction involving people, machinery and limited workplaces.Methods. A universal model for predicting occupational accidents takes into account influential factors such as organizational aspects, personal and collective protective equipment, on-the-job training and leadership factors. The selected networks achieved a prediction accuracy of >90%.Results. The study successfully identifies potential risks and critical worker groups leading to injuries. The sensitivity analysis provides insights for targeted safety measures and improved organizational practices.Conclusion. This data-driven approach makes a valuable contribution to safety in the mining industry. Implementation of the predictive model can reduce injuries and machine damage, and improve worker well-being. [ABSTRACT FROM AUTHOR] more...- Published
- 2024
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31. A Multi-Customer Vehicle Scheduling Optimization Method for Coal Intelligent Loading System.
- Author
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Wang, Yunrui, Li, Rui, Wang, Haoning, Wang, Le, and He, Xi
- Subjects
CUSTOMER satisfaction ,COAL mining ,SEARCH algorithms ,CARBON emissions ,SATISFACTION - Abstract
Intelligent loading systems are extensively employed in coal enterprises. Nevertheless, pre-loading customer vehicle scheduling predominantly depends on manual expertise. This frequently results in extended vehicle waiting periods, elevated carbon emissions, and reduced customer satisfaction, particularly in multi-customer scenarios. Therefore, this study introduces a multi-customer vehicle scheduling optimization approach for an intelligent coal loading system. Customer priorities are first identified to enhance satisfaction. Considering various customers and enterprise factors, the multi-customer vehicle scheduling model is established to minimize the total cost. The optimal vehicle scheduling scheme is obtained by using the enhanced sparrow search algorithm. The validity of the proposed approach is demonstrated through a case study of a coal mining enterprise. The results show that the total cost of the optimized plan was 79% lower than the traditional plan, which means a significant reduction in vehicle waiting time, and an improvement in customer satisfaction. [ABSTRACT FROM AUTHOR] more...
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- 2024
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32. Analysis on typical characteristics and causes of coal mine gas explosion accidents in China.
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Lin, Zhijun, Li, Min, He, Shan, Wang, Deming, Shi, Shiliang, and Wang, Dan
- Subjects
GAS explosions ,ASSOCIATION rule mining ,TEXT mining ,APRIORI algorithm ,COAL gas - Abstract
Large-scale coal mine gas explosion (CMGE) accidents have occurred occasionally and exerted a devastating effect on society. Therefore, it is essential to systematically identify the characteristics and association rules of causes of CMGE accidents through analysis on large-scale CMGE accident reports. In this study, 298 large-scale CMGE accidents in China from 2000 to 2021 were taken as the data sample, and mathematical statistical methods were adopted to analyze their general characteristics, coupling cross characteristics, and characteristics of gas accumulation and ignition sources. Moreover, the text mining technology and the Apriori algorithm were used for exploring the formation mechanism of CMGE accidents, during which 46 main causal factors were identified and 59 strong association rules were obtained. Furthermore, an accident causation network was constructed based on the co-occurrence matrix. The key causal items and sets of CMGE accidents were clarified through network centrality analysis. According to the research results, electrical equipment failure, cable short circuit, mine lamp misfire, hot-line work, and blasting spark are the key ignition sources of CMGE. Fan failure, airflow short circuit, and local ventilation fan damage are the main causes of gas accumulation. Besides, the confidence levels of two association rules of "static spark-fan failure" and "blasting spark-airflow short circuit" are higher than 70%, indicating that they are the two dominant risk-coupling paths of gas explosions. In addition, six causes appear frequently in the shortest risk paths of gas explosion and are closely related to other causes, i.e., fan failure, local ventilation fan damage, static sparks, electrical equipment failure, self-heating ignition, and friction impact sparks. This study provides a new perspective on identifying causes of accidents and their complex association mechanisms from accident report data for practical guidance in risk assessment and accident prevention. [ABSTRACT FROM AUTHOR] more...
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- 2024
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33. Study on the early warning of cracking and water inrush risk of coal mine roof and floor.
- Author
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Shichao Zhang, Xiuqi Wei, Liming Tang, Wenshuo Duan, Bin Gong, Chaomin Mu, Shujin Zhang, Huajin Li, and Dan Ma
- Subjects
WATER pressure ,RISK assessment ,WARNINGS ,ACHIEVEMENT - Abstract
Microseismic monitoring has proven to be an effective approach for detecting and preempting water inrush incidents within mining operations. However, challenges persist, particularly in terms of relying on a singular early warning index and the complexities involved in quantification. In response to these obstacles, a dedicated investigation was undertaken against the backdrop of mining activities at the 11,023 working face of Paner Coal Mine. Primarily, a novel methodology for categorizing the roof and floor into distinct zones was established based on the vertical distribution of microseismic events. Furthermore, this study delves into the dynamic evolution of key source parameters, such as microseismic energy, apparent stress, and apparent volume, amidst mining disturbances, enabling a comprehensive evaluation of the risk associated with roof and floor cracking, as well as potential water inrush incidents. A groundbreaking approach to early warning was proposed, operating on three pivotal dimensions: the depth of fractures, the intensity of fractures, and the likelihood of water inrush. Through rigorous validation during mining operations at the 11,023 working face, the efficacy was substantiated. Ultimately, the achievements offer invaluable insights and practical guidance for the advancement and implementation of water inrush early warning systems in coal mining contexts. [ABSTRACT FROM AUTHOR] more...
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- 2024
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34. Geochemical Characterization and Prediction of Water Accumulation in the Goaf under Extra-Thick Fully Mechanized Top-Coal-Caving Mining.
- Author
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Wang, Jianghong, Wang, Hongwei, Yin, Shaobo, Liao, Qingfa, Ju, Qiding, and Chen, Kai
- Subjects
MINE water ,WATER levels ,WATERWORKS ,COAL ,SUSTAINABLE development ,LONGWALL mining - Abstract
In multi-seam coal mining, the water accumulation in the goaf of the upper coal seam will seriously threaten the safety of the lower coal-seam recovery. How to accurately determine the water charging source in the goaf and predict the amount of water accumulation in the goaf after a certain time interval has become a major challenge that urgently needs to be solved in coal production. In this study, we consider the water-discharging goaf of the Tangjiahui Coal Mine as the object of research to investigate the problem of water accumulation in the goaf during the fully mechanized caving mining of extra-thick seams of top coal. We used geochemical methods, water-accumulation space methods, and large-well methods to analyze the hydraulic connections between goaf water and other aquifers, predict the amount of water accumulation in the goaf, and explore the characteristics of water level changes over time. We then used the results to discuss the relationship between the elevation of the accumulated water and the time taken for it to fill the goaf. The results showed that there is a hydraulic connection between the water in the airspace and the goaf water (GW), roof water (RW), floor water (FW) and Ordovician limestone water (OW); the volume of water in the goaf of the working face after mining was 2,106,838.496 m
3 . The average rate of water accumulation was 65.407 m3 /h, and the goaf was expected to have been filled in 32,211.208 h. The derived relationship between the water level and time was H 0 = − 10 − 12 t 3 + 10 − 7 t 2 − 0.0042 t + 814.61 (R 2 = 0.9837) . This study is of great significance for the sustainable development of the safety evaluation of water blocking coal pillars at the mine boundary. [ABSTRACT FROM AUTHOR] more...- Published
- 2024
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35. Drilling into joint and top-cutting pressure relief technology for a coal mine.
- Author
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LIU Bo, ZHANG Lei, YI Wei, WANG Yilong, HU Tao, GENG Huale, LIU Chengbo, and HUANG Xu
- Subjects
ANTHRACITE coal ,ROOF design & construction ,STRESS concentration ,ROCK deformation ,COAL mining ,COAL ,CLEAN coal technologies - Abstract
As a widely recognized and effective roadway support method, the top-cutting pressure relief technology, plays a positive role in improving the stress distribution inside the roadway and reducing the deformation of surrounding rock. To address the stress issues faced by the 1123 transportation roadway in Xichuan Coal Mine and reduce the deformation of surrounding rock, a drilling into joint and top-cutting pressure relief technology has been proposed. This technology can drill deeply into high-pressure zones, has a good pressure relief effect, and is flexible reliable, which is suitable for harder rocks in coal seams, and has high reliability and practicality. Through precise calculations using the stress function method, the upper and lower thresholds suitable for the drilling of the coal mine were determined, which are 14.14 and 6.32, respectively. The collapse state of the roof under different hole spacing was analyzed in depth using the numerical simulation method, and the stress distribution properties of solid coal before and after roof cutting were studied. The results show that the top cutting and pressure relief technology significantly improves the roof caving performance and can effectively prevent the occurrence of rockburst. At the same time, this technology can effectively reduce the stress transfer ratio, reducing the peak stress values in solid coal by 25.44% and pushing the peak point inward by 179.18%. The research results can providea reference for the selection of small coal pillar retention and support methods in the future. [ABSTRACT FROM AUTHOR] more...
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- 2024
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36. 煤矿生态保护修复工程技术方法研究: 以湖南谭家山煤矿为例.
- Author
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贺转利, 彭承梁, 彭祖武, and 黄江杰
- Subjects
STRIP mining ,WETLAND restoration ,COAL mining ,RESTORATION ecology ,MINES & mineral resources - Abstract
Copyright of China Mining Magazine is the property of China Mining Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...
- Published
- 2024
- Full Text
- View/download PDF
37. Dust concentration distribution and analysis of influencing factors in the heading face of Shangwan coal mine
- Author
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Yufu Li, Jie Wang, Zhibin Li, and Haitao Mo
- Subjects
dust concentration ,dust removal ,numerical simulation ,coal mine ,fluent ,Science - Abstract
Dust concentration in coal mine roadways significantly affects worker safety and health. Effective dust control is critical for optimizing the mine ventilation system and creating a safer working environment. This study investigates the impact of ventilation duct arrangements on dust concentration in a heading face, aiming to identify the optimal configurations for minimizing dust levels and enhancing worker safety. Using numerical simulations based on the gas-solid two-phase flow model in Fluent, we analyzed the effects of varying duct outlet distances and heights on airflow patterns and dust dispersion. Mesh generation, grid independence verification, and detailed parameter settings ensured accuracy and reliability of the simulation results. Results indicate that positioning the duct outlet 8 m from the heading face reduces dust concentration to approximately 39 mg/m³, while setting the duct height at 1.5 m notably decreases dust levels in the worker breathing zone. A mesh density of 576,449 cells ensured convergence and computational efficiency with an error margin within 2%. The findings provide practical insights into ventilation system optimization for coal mine heading faces, contributing to improved occupational health and operational safety. Future research should focus on validating these results through field experiments and addressing complex real-world conditions. more...
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- 2024
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38. Fault complexity degree in a coal mine and the implications for risk assessment of floor water inrush
- Author
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Dandan Wang, Wanghua Sui, and Zhiqiang Ji
- Subjects
Fault complexity degree ,box-meshing level ,water inrush rate ,risk assessment ,coal mine ,Environmental technology. Sanitary engineering ,TD1-1066 ,Environmental sciences ,GE1-350 ,Risk in industry. Risk management ,HD61 - Abstract
Faults significantly affect the stability of surrounding rock and stress distribution, which increases the possibility of water inrush disasters in a coal mine. Also, the precisely advanced prevention and control of floor limestone water become the foundation of ensuring mine safety and efficient production in coal mines. Fault development evaluation is one of the elements that control further transparent and fine studies. In this paper, the fault control index (FCI) is built based on the fractal dimension (Ds) and fault influence factor (E), which is determined according to the measured water inflow of water inrush points. The box meshing level is analyzed to calculate and compare the FCI. The results show that the box-meshing level affects the value of Ds and FCI and a meshing level of 6 seems to be the minimum standard of Ds for high accuracy. To verify the results, a comprehensive risk evaluation model of floor water inrush is established to illustrate the implications of fault complexity degree on safety mining. A stricter meshing grade when using the box-counting method in fault complexity degree is necessary for further studies in the precise prevention and control of mine hazards. more...
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- 2024
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39. Risk assessment of heavy metals in the soil of an abandoned coal mine area
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Yongkang ZHANG, Yaohua CAO, Naiqi FENG, Yan LIU, Yao ZHANG, Qing WANG, and Jia LIU
- Subjects
heavy metal pollution ,coal mine ,potential ecological hazard risk ,speciation of heavy metal ,bioavailability ,risk assessment ,Geology ,QE1-996.5 ,Mining engineering. Metallurgy ,TN1-997 - Abstract
During the coal mining process, a large amount of waste such as coal gangue and coal washing water is generated. The heavy metal pollutants in those wastes migrate and diffuse into the surrounding soil and water environment through sedimentation, runoff, leaching and other processes, posing a threat to the ecological environment. In order to study the heavy metal pollution in an abandoned coal mine area and to evaluate its ecological hazard risk, the contents of Cu, Pb, Zn, As, Cr, Ni, Hg, Cd elements in the coal gangue, water and soil samples of the mining area were detected. The single factor index method and potential ecological hazard index method were used to analyze the heavy metal pollution and its potential ecological hazard risk. The heavy metal pollution in the soil downstream of the coal washing plant in the mining area was mainly studied. The improved BCR continuous extraction method was used to analyze the forms of heavy metal elements (Cu, Zn, Cd) in the soil samples and the risk assessment coding method was employed to evaluate the bioavailability and environmental risks of heavy metal elements. The results show that: ① on average, the heavy metal contents in the coal gangue of the coal mine area are relatively low, with only Cr element content being slightly higher than that in soil. Moreover, the heavy metal element contents in the coal gangue do not exceed the risk intervention values for the soil of agricultural land, which has a little impact on heavy metal pollution in the soil. ② The heavy metal contents in the mine area’ exceed the standard, including that of Cu, Zn, Cd, Ni and As elements, and the Cd pollution is relatively serious. The pollution areas of Cu, Zn, and Ni elements are mainly concentrated in the western and southeastern parts of the gangue hill, with a certain overlap in spatial distribution. The As element pollution is distributed in the northeastern part of the gangue hill, while the Cd element pollution is widely distributed in the mine area, with moderate to severe pollution. ③ The Cd and Hg elements have potential ecological hazard risk, with a higher risk for Cd element. The comprehensive potential ecological hazard risk (RI) of heavy metal elements is mainly moderate to strong. ④ The contents of heavy metal elements in the soil downstream of the coal washing plant show an overall decreasing trend along the water flow direction, with the Cd element pollution being more severe, and the Cu, Zn, Ni, As element pollution concentrated within 200 m downstream of the coal washing plant. The heavy metal element contents of the profile sample shows a decreasing trend in the vertical direction, with no accumulation in the vertical direction. ⑤ The groundwater quality in the mine area is good, and the pH and the contents of heavy metal elements in the mine water meet the limit values of Class III surface water quality standards. The discharge of mine water drainage has a little impact on heavy metal pollution in the soil. ⑥ The proportions of acid extractable Cu and Zn elements are low, with low bioavailability, while that of Cd element is high, presenting a high-extremely high risk, with strong bioavailability and high environmental risk. Based on the current situation of heavy metal pollution in the mining area, it is recommended to further strengthen the prevention and control of heavy metal pollution, strengthen the source control, monitoring of agricultural food safety, and the investigation and research on the Cd element pollution. more...
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- 2024
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40. Merging TROPOMI and eddy covariance observations to quantify 5-years of daily CH4 emissions over coal-mine dominated region
- Author
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Wei Hu, Kai Qin, Fan Lu, Ding Li, and Jason B. Cohen
- Subjects
Methane ,TROPOMI ,Coal mine ,Mass balance equation ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Abstract A simple and flexible mass balance approach was applied to observations of XCH4 from TROPOMI to estimate CH4 emissions over Shanxi Province, including the impacts of advective transport, pressure transport, and atmospheric diffusion. High-frequency eddy-covariance flux observations were used to constrain the driving terms of the mass balance equation. This equation was then used to calculate day-to-day and 5 km × 5 km grided CH4 emissions from May 2018 to July 2022 based on TROPOMI RPRO column CH4 observations. The Shanxi-wide emissions of CH4, 126 ± 58.8 ug/m2/s, shows a fat tail distribution and high variability on a daily time scale (the 90th percentile is 2.14 times the mean and 2.74 times the median). As the number of days in the rolling average increases, the change in the variation decreases to 128 ± 35.7 ug/m2/s at 10-day, 128 ± 19.8 ug/m2/s at 30-day and 127 ± 13.9 ug/m2/s at 90-day. The range of values of the annual mean emissions on coal mine grids within Shanxi for the years 2018 to 2022 was 122 ± 58.2, 131 ± 71.2, 111 ± 63.6, 129 ± 87.1, and 138 ± 63.4 ug/m2/s, respectively. The 5-year average emissions from TROPOMI are 131 ± 68.0 ug/m2/s versus 125 ± 94.6 ug/m2/s on the grids where the EDGAR bottom-up database also has data, indicating that those pixels with mines dominate the overall emissions in terms of both magnitude and variability. The results show that high-frequency observation-based campaigns can produce a less biased result in terms of both the spatial and temporal distribution of CH4 emissions as compared with approaches using either low-frequency data or bottom-up databases, that coal mines dominate the sources of CH4 in Shanxi, and that the observed fat tail distribution can be accounted for using this approach. more...
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- 2024
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41. Mechanical responses and fracturing behaviors of coal under complex normal and shear stresses, Part II: Numerical study using DEM
- Author
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Z. Y. Song, F. Amann, W. G. Dang, and Z. Yang
- Subjects
Coal mine ,DEM ,Cyclic load ,Failure mechanism ,b-value ,Mining engineering. Metallurgy ,TN1-997 - Abstract
Abstract This work presents particle-based numerical simulations on coal pillars in a coal mine based underground water reservoir (CMUWR). We aim to replicate the stress–strain characteristics and present the acoustic emission behavior of the coal under complex dynamic stress paths. The study reveals failure characteristics of coal exposed to monotonic/cyclic shear load under constant/cyclic normal loads. Based on the evolution of stress-time-dependent bond diameter implemented in particle model, different damage paths are established for dry and water-immersed samples under two loading frequencies. Furthermore, the numerical Gutenberg–Richter’s b-value was calculated from the released energy emanating from bond failure, and this work presents the evolution of numerical Gutenberg–Richter’s b-value. The numerical simulation contributes to a micromechanical understanding of the failure mechanisms of coal under water-immersion and cyclic stress, providing valuable insights for strength prediction of CMUWR. more...
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- 2024
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42. Study on methane degradation by microbial agents based on chelating wetting agent carriers
- Author
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Yumiao Han, Lianman Xu, Runjie Zhang, Jin Lv, Fengshuo Yang, and Chen Ma
- Subjects
Methane-oxidizing bacteria ,Chelating wetting agent ,Carriers ,Methane degradation ,Gas pressure ,Coal mine ,Medicine ,Science - Abstract
Abstract Due to the low permeability characteristics of the deep gas-containing coal seam, the conventional prevention and control measures that cannot solve the problems of gas outbursts are unsatisfactory for the prevention and control of the coal and gas outbursts disaster. Therefore, in this study, a strain of methane-oxidizing bacteria M07 with high-pressure resistance, strong resistance, and high methane degradation rate was selected from coal mines. The growth and degradation abilities of M07 in chelating wetting agent solutions to assess its adaptability and find the optimal agent-to-M07 ratio. It provides a new method for integrating the reduction of impact tendency and gas pressure in deep coal mines. The experimental results show that M07 is a Gram-positive bacterium of the genus Bacillus, which has strong resistance and adaptability to high-pressure water injection. By degrading 70 mol of methane, M07 produces 1 mol of carbon dioxide, which can reduce gas pressure and reduce the risk of gas outbursts in coal mines. As the experiment proves, the best effect was achieved when the M07 concentration of the chelating wetting agent was 0.05%. The methane-oxidizing bacteria based on the chelating wetting agent as carriers prove a new prevention and control method for the integrated prevention and control of coal and gas outbursts in coal mines and also provide a new idea for microbial application in coal mine disaster control. more...
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- 2024
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43. Relationship between the current status of research on geological storage of solid, liquid and gas wastes in coal mines and the coordinated development of the ecological environment in China
- Author
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Kang ZHAO, Jun WU, Chao MA, Kaicheng ZHU, Jinglei NIE, and Hualong HU
- Subjects
coal mine ,three wastes (solid, liquid, gas) ,geological sequestration ,ecological environment ,coordinated development ,green mine ,Geology ,QE1-996.5 ,Mining engineering. Metallurgy ,TN1-997 - Abstract
China is a country in the world with the serious environmental pollution of coal mine “three wastes” (solid, liquid, gas). A lot of in-depth research and practice has been carried out on the utilization and treatment of “three wastes”. However, there are still many problems such as imperfect standards and norms, small scale of treatment and unsound technology. In order to solve the problem of synergistic development of low-cost geological storage of large-scale “three wastes” and ecological environment in China’s coal mines, on the basis of the definition of geological storage in other countries, the connotation of geological storage in China has been expanded. The progress and current status of research on the geological storage of “three wastes” are analyzed. Literature and patents related to the geological storage of “three wastes” at home and abroad are reviewed. The problems faced by China in carrying out the geological storage of “three wastes” and the suggestions for further development are put forward. It is pointed out that the main problem faced by the geological storage of “three wastes” in China is the inadequacy of the standards and regulations in the field of environment, especially the extensive lack of standards for the deep-well injection of waste liquids. The systematic research has shown that the research institutions in China are paying increasing attention to research in the field of the geological storage of the “three wastes”, and that the results of the research account for a high percentage of research in the world. China’s coal mine “three wastes” geological storage and ecological environment synergistic development awareness and system is being formed. However, there is insufficient support for research on the large-scale geological storage of “three wastes”, the cyclic system of geological storage of “three wastes” in the whole cycle of coal mining, and the synergistic relationship between CO2 capture, utilization and storage (CCUS) technology and the ecological environment. This seriously restricts the large-scale implementation and application of the concepts, technologies and projects of geological storage. China should expeditiously strengthen the scientific and technological research and development of coal mine “three wastes” geological storage technology and ecological environment synergistic development. Through the establishment of improved standards and norms, increased technological research and development, and strengthened environmental supervision and other measures, the green and sustainable development in China’s coal mines is promoted, helping the China’s “dual-carbon” goal to be realized. more...
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- 2024
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44. An improved LSSVM discrimination model based on factor analysis and moth flame optimization algorithm for identifying water inrush sources across multiple aquifers in mines.
- Author
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Bi, Yaoshan, Shen, Shuhao, and Wu, Jiwen
- Subjects
OPTIMIZATION algorithms ,MINE water ,SUPPORT vector machines ,FACTOR analysis ,COAL mining - Abstract
To accurately and swiftly identifying the source of water inrush in mines, a discrimination model based on factor analysis (FA) and the moth flame optimization (MFO) algorithm coupled with least squares support vector machine (LSSVM) is proposed. Drawing from the hydrogeological conditions of the Yuanyi Mine in the Huaibei Mining Area, water samples from three aquifers were collected, and ten hydrochemical indicators were selected for the purpose of identifying the water inrush sources. Firstly, FA was performed on these ten indicators to extract five new components that can comprehensively reflect most of the information of all indicators, eliminating redundant information between the original indicators. Then, the extracted new components was used as inputs to the LSSVM model. Finally, the MFO algorithm was used to automatically optimize the two pivotal parameters of the penalty factor C and the kernel function parameter g of LSSVM, and a discrimination model based on FA-MFO-LSSVM was established. Furthermore, a comparative analysis of the discrimination performance of the FA-MFO-LSSVM model against five other models was carried out. The results unequivocally indicate that the FA-MFO-LSSVM model has high discrimination accuracy for both training and testing samples, and compared to the other five models, this model exhibits stronger discriminative performance. [ABSTRACT FROM AUTHOR] more...
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- 2024
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45. Mechanical responses and fracturing behaviors of coal under complex normal and shear stresses, Part II: Numerical study using DEM.
- Author
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Song, Z. Y., Amann, F., Dang, W. G., and Yang, Z.
- Subjects
SHEARING force ,COAL mining ,COAL ,CYCLIC loads ,MINES & mineral resources ,WATER immersion ,ACOUSTIC emission ,ACOUSTIC emission testing ,POLLUTION management - Abstract
This work presents particle-based numerical simulations on coal pillars in a coal mine based underground water reservoir (CMUWR). We aim to replicate the stress–strain characteristics and present the acoustic emission behavior of the coal under complex dynamic stress paths. The study reveals failure characteristics of coal exposed to monotonic/cyclic shear load under constant/cyclic normal loads. Based on the evolution of stress-time-dependent bond diameter implemented in particle model, different damage paths are established for dry and water-immersed samples under two loading frequencies. Furthermore, the numerical Gutenberg–Richter's b-value was calculated from the released energy emanating from bond failure, and this work presents the evolution of numerical Gutenberg–Richter's b-value. The numerical simulation contributes to a micromechanical understanding of the failure mechanisms of coal under water-immersion and cyclic stress, providing valuable insights for strength prediction of CMUWR. [ABSTRACT FROM AUTHOR] more...
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- 2024
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46. Merging TROPOMI and eddy covariance observations to quantify 5-years of daily CH4 emissions over coal-mine dominated region.
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Hu, Wei, Qin, Kai, Lu, Fan, Li, Ding, and Cohen, Jason B.
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COAL mining ,ATMOSPHERIC diffusion ,DATABASES ,EDDIES ,TEMPORAL databases - Abstract
A simple and flexible mass balance approach was applied to observations of XCH
4 from TROPOMI to estimate CH4 emissions over Shanxi Province, including the impacts of advective transport, pressure transport, and atmospheric diffusion. High-frequency eddy-covariance flux observations were used to constrain the driving terms of the mass balance equation. This equation was then used to calculate day-to-day and 5 km × 5 km grided CH4 emissions from May 2018 to July 2022 based on TROPOMI RPRO column CH4 observations. The Shanxi-wide emissions of CH4 , 126 ± 58.8 ug/m2 /s, shows a fat tail distribution and high variability on a daily time scale (the 90th percentile is 2.14 times the mean and 2.74 times the median). As the number of days in the rolling average increases, the change in the variation decreases to 128 ± 35.7 ug/m2 /s at 10-day, 128 ± 19.8 ug/m2 /s at 30-day and 127 ± 13.9 ug/m2 /s at 90-day. The range of values of the annual mean emissions on coal mine grids within Shanxi for the years 2018 to 2022 was 122 ± 58.2, 131 ± 71.2, 111 ± 63.6, 129 ± 87.1, and 138 ± 63.4 ug/m2 /s, respectively. The 5-year average emissions from TROPOMI are 131 ± 68.0 ug/m2 /s versus 125 ± 94.6 ug/m2 /s on the grids where the EDGAR bottom-up database also has data, indicating that those pixels with mines dominate the overall emissions in terms of both magnitude and variability. The results show that high-frequency observation-based campaigns can produce a less biased result in terms of both the spatial and temporal distribution of CH4 emissions as compared with approaches using either low-frequency data or bottom-up databases, that coal mines dominate the sources of CH4 in Shanxi, and that the observed fat tail distribution can be accounted for using this approach. [ABSTRACT FROM AUTHOR] more...- Published
- 2024
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47. KARTIRANJE PROSTORSKE PORAZDELITVE ONESNAŽEVAL ZRAKA V PROVINCI QUANG NINH (VIETNAM) NA PODLAGI PODATKOV SENTINEL 5P.
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Le Hung Trinh, Van Phu Le, Thi Hanh Tong, and Sinh Dinh Mai
- Subjects
- *
AIR quality monitoring , *COAL reserves , *AIR pollutants , *MINES & mineral resources , *COAL mining - Abstract
Vietnam is a country with rich mineral resources, of which coal reserves are about 8.6 billion tons, concentrated mainly in the coal basin of Quang Ninh province. Besides the economic and social benefits, coal mining has negative impacts on the environment, such as air and water pollution. Air pollution in coal mining areas seriously affects human health and the environment. This study presents the results of mapping the quarterly spatial distribution maps of air pollutants in Quang Ninh province, including CO, NO2, O3 and SO2 from Sentinel 5P TROPOMI data. Sentinel 5P TROPOMI data on four air pollutant concentrations in the entire year 2023 was collected using the Google Earth Engine (GEE) cloud computing platform and then averaged over the quarters. The results of air pollution assessment from remote sensing data are compared with the limit values of basic parameters in the air in QCVN 05:2013/BTNMT National technical regulation on air quality. Analysis of the achieved results show that the concentrations of CO, NO2, O3 and SO2 in Quang Ninh province in 2023 are all high compared to regulations in QCVN, especially in the southern region where large coal mines are concentrated. The results received in this study provide timely information to help managers monitor air quality in coal mining areas. [ABSTRACT FROM AUTHOR] more...
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- 2024
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48. Job demands, control, social support and mental health in workers of thermal power plants and underground mines: A comparative study.
- Author
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Şentürk, Ayşe and Kuzu Durmaz, Ayşe
- Subjects
- *
MENTAL health personnel , *JOB descriptions , *MINES & mineral resources , *COAL mining , *MINERS - Abstract
This descriptive study was conducted to compare the job demands, job control, social support and mental health status of thermal power plant and underground coal mine workers. 158 workers in thermal power plant and 162 workers in underground coal mine participated in the study. The results unearthed that thermal power plant workers had 2.3 times better mental health (p < 0.001 OR = 2.3 CI = 1.50-3.74) and 3.0 times lower job demands (p < 0.001 OR = 3.0 CI = 1.91-4.92) than coal mine workers. In the study, it was determined that mental health was positively affected as job control and social support increased in both thermal power plant and underground mine workers (p < 0.05); there was no significant relationship between job demands and mental health (p > 0.05). These results indicate that underground mine workers are at higher risk in terms of mental health and job demands than thermal power plant workers. [ABSTRACT FROM AUTHOR] more...
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- 2024
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49. Research of Localization Method of Coal Mine Snake Detecting Robot.
- Author
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Yun Bai, Feng Xing, Hao-bo Wang, and Xin-yue Liu
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ARTIFICIAL neural networks ,COAL mining ,RADIAL basis functions ,MINES & mineral resources ,ROBOTS ,ANGLES ,LOCALIZATION (Mathematics) - Abstract
It is a difficult problem to locate the snake detecting robot in the closed complex environment of underground coal mine. The traditional localization methods usually depend on the estimation of complex ground parameters in coal mine tunnel, which leads to the complexity of establishing the localization model. In response to this compelling problem, we propose the new method to estimate the trajectory curvature and path angle of the robot, and a simple localization model of snake robot based on turning is established. On this basis, the dead reckoning localization method based on the combination of a high-precision 6-axis inertial navigation module MPU6050 and magnetic Hall encoders is proposed, which reduces the difficulty of traditional localization methods. In order to improve the localization accuracy of the robot, an algorithm combines Kalman filter and Deep learning is proposed. Firstly, the Kalman filter algorithm is used to eliminate the white Gaussian noise in the path angle signal of robot. Then, aiming at various drifts from low-frequency stage in the path angle signal, a prediction model of path angle output value based on LSTM (Long Short-Term Memory) deep neural network is established, which can predict the path angle output value for a period in the future, thereby achieving the robot's dead reckoning. The simulation and experiment results prove that the relative localization accuracy of the robot can be improved, in the simulated coal mine tunnel, the maximum relative error of the robot's location is 1.872×10
-9 cm, and the maximum error of the path angle is 0.0028 rad, the determination coefficient R² is 1.000, which reflect that the established LSTM model has higher prediction accuracy, better performance, and stronger generalization ability than RBF (Radial Basis Function) neural network. The method proposed in this paper can provide a new idea for the localization problem of snake robots in the underground unstructured complex environment after the disaster. [ABSTRACT FROM AUTHOR] more...- Published
- 2024
50. Using borehole radar detecting hydraulic fracturing crack in near horizontal holes in coal mine.
- Author
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Jiang Bici, Lin Zhang, and Yuantian Sun
- Subjects
HYDRAULIC fracturing ,HORIZONTAL wells ,COAL mining ,ROCK deformation ,RADAR ,GAS wells ,SHALE gas - Abstract
Currently, hydraulic fracturing technology is widely implemented for controlling the surrounding rock and enhancing permeability in low-permeability coal seams. Evaluating the effectiveness of hydraulic fracturing is a critical component of hydraulic fracturing operations. This study addresses the challenges in assessing the location, extension angle, and initial width of fracturing fractures within the current framework of hydraulic fracturing effectiveness evaluation in coal mines. We propose utilizing single-hole reflection borehole radar to evaluate the hydraulic fracturing effect, and through numerical simulation, we analyze the response characteristics of borehole radar when detecting various hydraulic fracturing-induced cracks. Initially, five models representing hydraulic fracturing cracks and two models for non-hydraulic fracturing cracks were established. Subsequently, the responses of borehole radar with central frequencies of 100, 200, and 400 MHz to cracks of identical shapes were analyzed. Additionally, the response characteristics of borehole radar with a 200 MHz central frequency to cracks of varying lengths (1, 2, 3 m), widths (4, 8, 40 cm), and angles (90°, 45°, 15°) were examined. Finally, a comparative analysis was conducted between hydraulic and non-hydraulic fracturing cracks. A branch hole was employed to simulate a hydraulic fracturing crack, allowing for an analysis of the borehole radar's response characteristics in practical scenarios. The findings indicate that borehole radar is a viable tool for assessing hydraulic fracturing effects, providing a theoretical foundation for identifying the position of cracks, evaluating their effectiveness, and determining the regional effectiveness of the hydraulic fracturing crack system. [ABSTRACT FROM AUTHOR] more...
- Published
- 2024
- Full Text
- View/download PDF
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