Prevention and control for water hazard in Fenxiao coal mine

Author(s):  
Zhihong He
2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Tianwei Lan ◽  
Chaojun Fan ◽  
Jun Han ◽  
Hongwei Zhang ◽  
Jiawei Sun

Rock burst induced by mining is one of the most serious dynamic disasters in the process of coal mining. The mechanism of a rock burst is similar to that of a natural earthquake. It is difficult to accurately predict the “time, space, and strength” of rock burst, but the possibility of rock burst can be predicted based on the results of microseismic monitoring. In this paper, the rock burst system under the tectonic stress field is established based on the practice of coal mining and the result of mine ground crustal stress measurement. According to the magnitude of microseismic monitoring, the amount of the energy and spatial position of the rock burst are determined. Based on the theory of explosion mechanics, aiming at the prevention and control of rock burst in the coal mine, the technique of liquid CO2 fracturing blasting is put forward. By the experiment of blasting mechanics, the blasting parameters are determined, and the controlling mechanism of rock burst of liquid CO2 fracturing blasting is revealed. The application of liquid CO2 fissure blasting technology in the prevention and control of rock burst in Jixian Coal Mine shows that CO2 fracturing blasting reduces the stress concentration of the rock burst system and transfers energy to the deeper part, and there is no open fire in the blasting. It is a new, safe, and efficient method to prevent and control rock burst, which can be applied widely.


2013 ◽  
Vol 353-356 ◽  
pp. 303-306
Author(s):  
Zhi Chao Tian ◽  
Long Hao Dong ◽  
Min Ma ◽  
Ye Jiao Liu

According to the actual monitoring data of mining environment and rock burst happening on the 3511 fully-mechanized workface in Anyuan coal mine, the research of the rock burst on the workface and its surrounding rock of gob-side entry is done and the reasonable supporting scheme is determined. The research results are of great guiding importance to the coal mining that has similar condition, provide scientific basis for the control technology of rock burst on the workface and its gob-side entry as well as the reasonable identification of support parameters on the gob-side tunnel, and supply technology protection in order to accelerate the advancing speed of workface. Finally it can produce larger economic benefit.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Xuchao Huang ◽  
Enmao Wang ◽  
Gang Wang ◽  
Jiuyuan Fan

Hydrogen sulphide is a toxic gas often present in coal seams and seriously threatens the lives and health of underground workers in coal mines. In this study, we theoretically modelled hydrogen sulphide generation in extremely thick underground coal mines with the +575 level #45 coal seam of Wudong Coal Mine as an example and obtained the on-site hydrogen sulphide emission pattern and spatial distribution features by combining field measurements and computational fluid dynamics simulation. The results showed that hydrogen sulphide mainly exists in the coal porous system in an adsorbed state. Because hydrogen sulphide has a molecular weight greater than the average molecular weight of air molecules, its concentration decreases with the increase of altitude to the bottom plate. When mining the upper stratified coal stratum, it diffuses widely in the working space; while when mining the lower coal stratum, it mainly concentrates at the bottom of the working face. Based on these analyses, on-site treatments were carried out using mixtures with different concentrations of sodium carbonate and sodium bicarbonate. In addition, different combinations of catalysts as well as type A and type B wetting agents were also tested. Eventually, a neutral KXL-I absorbent was developed, and the process of preinjecting absorbent and spraying absorbent was designed. The results showed that the newly developed KXL-I absorbent has high hydrogen sulphide absorption ability and is suitable for use as an absorbent in Wudong Coal Mine; preinjecting and spraying the absorbent can effectively prevent hydrogen sulphide disasters in the +575 level #45 coal seam in Wudong Coal Mine with the optimal final concentration of 0.9% and the absorption rate of 87% at the shearer of 66.6% at the support. Overall, our study provides valuable information for the prevention and control of hydrogen sulphide disasters in coal mines.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhenghe Liu ◽  
Peiyun Zhao ◽  
Lusheng Yang ◽  
Jingui Zhao ◽  
Hailong Ye ◽  
...  

Water inrush from coal seam floors is one major geological obstacle hindering safe and efficient production activities in mines. Determining the source of water inrush can facilitate its prediction and guide decisions regarding measures for prevention and control. The process of identifying the location of hidden hydraulic contact points in different confined aquifers forms the basis of hydrogeological explorations. It is also the basis for categorizing mine areas prone to water inrush and making qualitative decisions regarding the prevention and control of water inrush. In this study, the positions of hidden hydraulic contact points between the Ordovician Fengfeng and Shangmajiagou formations in the basement of the Liyazhuang coal mine were determined using numerical simulations of the flow fields. First, each node of the finite element grid was considered as a water inrush point to determine the water level at other nodes. Subsequently, the error between measured and simulated water levels, determined based on the flow fields, was determined using the least squares method. The node with the minimum error was then considered as the hidden hydraulic contact point. The simulation results for the flow field indicate a distance of 5000 m between the hydraulic connection and the water inrush points located between the peak formation and the Majiagou aquifer in the Liyazhuang coal mine. Furthermore, the hydraulic relationship between them is poor. Observational data of water inrush from the floor of the No. 2 coal seam and the water level of the confined aquifer in the Liyazhuang coal mine, including the water quality test data of different Ordovician ash aquifers, show that the source of water inrush from the floor of the No. 2 coal seam is the aquifer of the Fengfeng Formation. This finding is consistent with the results of the numerical simulations of the flow field. The results demonstrate that, in mining areas subjected to high pressures, numerical simulations of the flow field can serve as an effective tool for determining the location of hidden hydraulic contact points.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Chengchun Xue ◽  
Anye Cao ◽  
Wenhao Guo ◽  
Songwei Wang ◽  
Yaoqi Liu ◽  
...  

Coal pillar bursts continue to be a severe dynamic hazard. Understanding its mechanism is of paramount importance and crucial in preventing and controlling its occurrence. The extreme roadway deformations from the asymmetric isolated coal pillars in the central mining district of YaoQiao Coal Mine have responded with frequent intense tremors, with risky isolated coal pillar bursts. The theoretical analysis, numerical simulation, and field measurements were done to research the impact of spatial overburden structure and stress distribution characteristics on the isolated coal pillar area, aiming to reveal the mechanism of coal pillar burst leading to the practice of prevention and control in the asymmetric isolated coal pillar area. The study shows that the overburden structure of the asymmetric is an asymmetric “T” structure in the strike-profile, and the stress in the coal pillar is mostly asymmetric “saddle-shaped” distribution, with the peak stress in the east side of the coal pillar, and the coal pillar is a “high stress serrated isolated coal pillar.” Numerical simulation results showed that the support pressure in the isolated coal pillar area on the strike profile was asymmetrically “saddle-shaped” distribution. The peak vertical stress in the coal pillar area continued to rise and gradually shifted to the mining district's deep part. As a result, the response of the roadway sides to the dynamic load disturbance was more pronounced. They developed a coal burst prevention and control program of deep-hole blasting in the roof of asymmetrical isolated coal pillar roof and unloading pressure from coal seam borehole. Monitored data confirmed that the stress concentration was influential in the roadway’s surrounding rock in the asymmetric isolated coal pillar area, circumventing coal pillar burst accidents. The research outcomes reference the prevention and control of coal bursts at isolated working faces of coal pillars under similar conditions.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hui Zhang ◽  
Weihai Han ◽  
Youlin Xu ◽  
Zhenfeng Wang

In recent years, with the increasing level of mechanization, automation, and intelligence in mine mining, dust pollution in the working environment of coal mines has become increasingly serious. Coal mine dust prevention is an important work related to the life, health, and production safety of miners, and it is also one of the technical problems of mine safety in production. With the continuous revision and improvement of China′s Occupational Disease Prevention and Control Law, coal mining enterprises have generally strengthened the publicity, prevention, and control of occupational diseases among employees, and the control of coal mine dust has been used as a means for enterprises to improve the production environment and strengthen the occupational health of employees. Key work-based studies have shown that China’s coal mines have formed a theoretical system and technology system of dust prevention and control. In the future, China’s coal mines will start from intelligent dust prevention, achieve high-precision dust sensing-transmission-assessment and early warning, and develop a combined dust collector that integrates the functions of atomization dust removal, miniaturization, dry and wet mixing, and large air suction capacity. The combined dust collector realizes the efficient ventilation control and dust removal of the fine dust in wide-area complex spaces such as fully mechanized mining face and fully mechanized mining face. At the same time, breakthroughs have been achieved in low-permeability coal seams, such as strong hydraulic permeability-enhancing technology, intelligent dust-proof robots, and chemical dust suppression. This article introduces the basic concepts, generation, distribution, and hazards of coal mine dust and analyzes the characteristics, applicable conditions, and use effects of various dust control measures such as ventilation dust removal and wet dust removal. Moreover, this article also proposes specific prevention and control measures for related occupational diseases and discusses the development trend of dust prevention and control technology in the hope of providing guidance and reference for coal mine dust prevention and control.


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