scholarly journals Stress Distribution Around Mechanized Longwall Face at Deep Mining in Quang Ninh Underground Coal Mine

2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Manh Tung BUI ◽  
Tien Dung LE ◽  
Trong Hung VO
Keyword(s):  
Stress Distribution ◽  
Sea Level ◽  
Coal Mine ◽  
Coal Mines ◽  
Longwall Face ◽  
Geological Condition ◽  
Deep Mining ◽  
Roof Fall ◽  
The Impact ◽  
Quang Ninh

Quang Ninh underground coal mines are currently in the phase of finishing up the mineralreserves located near the surface. Also, in this phase, a number of coal mines have opened and preparednew mine sites for the extraction of the reserves at greater depth. Several mines have mined at -350 mdepth and are driving opening excavations at -500 m depth below sea level. The mining at greater depthfaces many difficulties, such as a significant increase in support and excavation pressures. The longwallface pressure is mostly manifested in great magnitude that causes support overloaded and jumped andface spall/roof fall. This paper, based on the geological condition of the Seam 11 Ha Lam coal mine,uses the numerical program UDEC for studying the impact of mining depth on stress distribution aroundthe longwall face. The results show that the deeper the mining is, the greater the plastic deformationzone is. The peak front abutment stress moves closer to the coal wall, mainly concentrating on theimmediate roof and top coal. The top coal is greatly broken, and its bearing capacity is decreased. Somesolutions to the stability of roof strata are proposed, and a proper working resistance of support isdetermined. Additionally, the paper suggests that the starting depth for deep mining in Quang Ninhunderground coal mines should be -350 m below sea level.

scholarly journals Methane Content Estimation in DuongHuy Coal Mine

2018 ◽  
Vol 35 ◽  
pp. 01005 ◽  
Author(s):  
Van Thinh Nguyen ◽  
Waldemar Mijał ◽  
Vu Chi Dang ◽  
Thi Tuyet Mai Nguyen
Keyword(s):  
Experimental Data ◽  
Coal Mining ◽  
Coal Mine ◽  
Coal Mines ◽  
Methane Content ◽  
Underground Coal Mining ◽  
Coal Seams ◽  
Underground Coal Mine ◽  
Different Depths ◽  
Quang Ninh

Methane hazard has always been considered for underground coal mining as it can lead to methane explosion. In Quang Ninh province, several coal mines such as Mạo Khe coal mine, Khe Cham coal mine, especially Duong Huy mine that have high methane content. Experimental data to examine contents of methane bearing coal seams at different depths are not similar in Duong coal mine. In order to ensure safety, this report has been undertaken to determine a pattern of changing methane contents of coal seams at different exploitation depths in Duong Huy underground coal mine.

Research on Bursting Liability and its Preventive Measures of -906m Deep Coal and Rock in Zhuji Coal Mine

2012 ◽  
Vol 170-173 ◽  
pp. 428-433 ◽  
Author(s):  
Dong Ming Guo ◽  
Hua Jun Xue ◽  
Li Juan Li ◽  
Jun Long Xue ◽  
Gui He Li
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Water Injection ◽  
Elastic Strain Energy ◽  
Hole Drilling ◽  
Energy Index ◽  
Deep Mining ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
The Impact

Rock burst is a common mine dynamic phenomenon in the world, and the research on bursting liability of coal and rock is the foundation of rock burst’s prevention and treatment. This paper has a research on bursting liability of coal and rock of 11-2 coal seam which is the main coal seam of Zhuji coal mine, and through the research and analysis of coal seam burst energy index(bursting energy index, elastic strain energy index, duration of dynamic fracture) and rock seam burst energy index(bending energy index), this paper given that seam and rock in deep mining section of Zhuji coal mine has bursting liability, put forward a series of countermeasures such as the previous water injection, hole-drilling method, blasting distressing to the coal seam with the impact disaster for deep mining in Zhuji coal mine.

scholarly journals Assessment and Quantification of Risks Associated with Small Scale Mining, Khyber Pakhtunkhwa, Pakistan

2020 ◽  
Vol 11 (3) ◽  
pp. 65-69
Author(s):  
Zahid Ur Rehman ◽  
Saira Sherin ◽  
Sajjad Husain ◽  
Noor Muhammad ◽  
Talat Bilal
Keyword(s):  
Coal Mine ◽  
Ventilation System ◽  
Coal Mines ◽  
Health And Safety ◽  
Mining Industry ◽  
Small Scale ◽  
Khyber Pakhtunkhwa ◽  
Data Analyses ◽  
Roof Fall ◽  
One Year

Small scale mining industry is considered more hazardous than other industries worldwide. Large number of workers receive minor and major injuries leading to disabilities or loss of lives due to frequent accidents in mines. Main causes of accidents in mines are fall of roof, improper ventilation system, gases, fires and mine explosions. Beside these hazards, violation of rules and regulations for mine workers are common, which also cause accidents. This paper is focused on issues associated with the health and safety of workers of Cherat Coal Mines (CCM), Abbottabad Coal Mine (ACM) and Abbottabad Soapstone Mine (ASM), Pakistan. The collected data were analyzed with SPSS computer statistics software. The data analyses indicated that the lack of education and violation of safety laws cause accidents in mines. Results show that problems that were rated higher by more than 60% of workers included slide and fall, dust, roof fall and explosive related hazards. In survey more than 50% of the workers admitted the existence of gases, fire and low height mines are common hazards in their workplace. The results also indicated that not only workers but management are also affected by accidents. More than 17% of worker in CCM faced serious accidents up to 3 times during one year. Up to 26% of workers in CCM, 13% in ACM and 15% in ASM suffered accidents for which they had 3 workdays off. It has been concluded that training should be arranged, especially the safety related training on regular basis to reduce the risk of accidents.

scholarly journals Study on Stress Relief of Hard Roof Based on Presplitting and Deep Hole Blasting

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Peng Gong ◽  
Yongheng Chen ◽  
Zhanguo Ma ◽  
Shixing Cheng
Keyword(s):  
Stress Distribution ◽  
Coal Mine ◽  
Coal Pillar ◽  
Deep Hole ◽  
Hard Roof ◽  
Formation Conditions ◽  
Coal Pillars ◽  
Mining Coal ◽  
The Impact ◽  
Pillar Size

For the problem that the hard roof causes wider end-mining coal pillar, and the roadway is greatly affected by mining, this paper took Shanxi Luning Coal Mine as the engineering background; based on the stress distribution characteristics of the coal pillar, the calculation method of the limit end-mining coal pillar size was given; considering the formation conditions and transmission forms of the advanced abutment stress, a method combining presplitting and deep hole blasting was proposed to weaken the advanced abutment stress. The numerical simulation was used to analyze the stress distribution of coal pillars, which was verified by on-site industrial tests. The results showed that the presplitting can achieve the blocking of stress. The closer it is to the peak of the abutment stress, the better the blocking effect. Deep hole blasting can weaken the source of the advanced abutment stress and reduce the peak of abutment stress. With the combination of the two blasting methods, the end-mining coal pillar size of Luning Coal Mine can be reduced to 60 m. The method combining presplitting and deep hole blasting can effectively reduce the end-mining coal pillar size and reduce the impact of mining on the deformation of the dip roadway.

scholarly journals Development Of Software To Evaluate Roof Fall Risk In Bord And Pillar Method - Depillaring Phase

2015 ◽  
Vol 61 (2) ◽  
pp. 14-22 ◽  
Author(s):  
Devidas S. Nimaje ◽  
Shiva Sai
Keyword(s):  
Coal Mine ◽  
Fall Risk ◽  
Coal Mines ◽  
Mining Equipment ◽  
Underground Coal Mine ◽  
Company Limited ◽  
Roof Fall ◽  
Considerable Damage

Abstract Roof fall is one of the major problems of the bord and pillar coal mines during the depillaring phase. Roof fall not only causes considerable damage to the mining equipment but also to the miners. To keep in view, development of software is essential for the calculation of roof fall risk to reduce the accidents to a certain extent. In this paper, the software has been developed and tested on seam-2, the main panel of RK-5 underground coal mine, Singareni Collieries Company Limited, India and corresponding roof fall risk was calculated. The best combination of the parameters causing roof fall risk was evaluated to reduce the risk.

scholarly journals Justification of the use of a vegetal additive to diesel fuel as a method of protecting underground personnel of coal mines from the impact of harmful emissions of diesel-hydraulic locomotives

2021 ◽  
Vol 247 ◽  
pp. 39-47
Author(s):  
G. Korshunov ◽  
Anzhelika Eremeeva ◽  
Carsten Drebenstedt
Keyword(s):  
Carbon Monoxide ◽  
Working Conditions ◽  
Coal Mine ◽  
Diesel Fuel ◽  
Coal Mines ◽  
Operating Mode ◽  
Chemical Factor ◽  
Harmful Emissions ◽  
Hydrotreated Diesel ◽  
The Impact

Equipment with diesel engines is used in all mining enterprises. Monorail diesel transport is of great importance in coal mines, as it facilitates the heavy labor of workers when transporting materials and people, fixing mining workings, refueling and repairing equipment, which leads to an increase in the speed of tunneling operations. Reducing the concentration of harmful gases from diesel-hydraulic locomotives at the workplaces of coal mine locomotive drivers can be ensured by the use of additives to diesel fuel that reduce the volume of harmful gas emissions during the operation of diesel-hydraulic locomotives. Additive ester-based on vegetal oil in the amount of 5 mass % in a mixture with hydrotreated diesel fuel reduces the concentration of carbon monoxide by 19-60 %, nitrogen oxides by 17-98 %, depending on the operating mode of the engine, the smoke content of the exhaust gases is reduced to 71 %. There is an improvement in working conditions at the workplace of the driver of a diesel-hydraulic locomotive by the chemical factor due to the reduction of the class of working conditions from 3.1. to 2.

Geological Features of Kailuan Coal Mine and the Laws of Pressure Bump for Deep Mining

2011 ◽  
Vol 201-203 ◽  
pp. 408-412
Author(s):  
Lian Feng Gao ◽  
Ying Zhang ◽  
Yao Han Niu ◽  
Ying Chun Wang ◽  
Juan Sun ◽  
...  
Keyword(s):  
Coal Mine ◽  
High Stress ◽  
Mine Safety ◽  
Deep Mining ◽  
Geological Conditions ◽  
Key Factor ◽  
Pressure Bump ◽  
Safety Production ◽  
Permian Coal ◽  
The Impact

Pressure bump in coal mine production safety is a serious disaster. Geological conditions in Kailuan Mine are complex. Coal strata based on the Carboniferous - Permian coal. The roof and floor are made of sandstone and mudstone with poor rigidity. Fault development and mine have large amount of water inflow. Most of mine are already getting into the mining stage over one thousand meters deep. Increasing stress and high stress induced pressure bump as a key factor. In this paper, according to geological characteristics of Kailuan Coal, it analyzes the impact and the laws of pressure bump in the representation of deep mining phase, which have certain reference for coal mine safety production.

scholarly journals Numerical Analysis of Longwall Gate-Entry Stability under Weak Geological Condition: A Case Study of an Indonesian Coal Mine

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4710
Author(s):  
Takashi Sasaoka ◽  
Pisith Mao ◽  
Hideki Shimada ◽  
Akihiro Hamanaka ◽  
Jiro Oya
Keyword(s):  
Numerical Analysis ◽  
Coal Mine ◽  
Longwall Face ◽  
Geological Condition ◽  
Indonesian Coal ◽  
The Stability ◽  
Roof Support

The present research primarily focuses on the investigation of gate-entry stability of longwall trial panel under weak geological condition in Indonesia coal mine by means of numerical analysis. This work aims at identifying appropriate roof support at 100 m and 150 m of depth during gate development. Due to depth depending competency of dominant rock, the stability of gate-entry at 100 m of depth can be optimized by leaving at least 1 m of remaining coal thickness (RCT) above and below the gate-entry. The appropriate support for the trial panel gate-entry is steel arch SS540 with 1 m and 0.5 m spacing for 100 m and 150 m of depth, respectively. The influence of panel excavation on gate-entry is also discussed. Regarding the aforementioned influence, the utilization of additional gate mobile support is recommended at least 10 m from the longwall face.

scholarly journals Complete methodology to resist in mechanism longwall mine 6# at Nam Mau Coal Company

2019 ◽  
Vol 61 (1) ◽  
pp. 116-123
Author(s):  
Nguyen Phi Hung ◽  
Nguyen Cao Khai ◽  
Bui Manh Tung ◽  
Lai Quang Trung ◽  
Tran Van Thang ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mines ◽  
Field Measurements ◽  
Longwall Face ◽  
Support Pressure ◽  
Geological Condition ◽  
Hydraulic Support ◽  
Working Face ◽  
Calculation Results ◽  
Longwall Mine

Geological condition of 6# at Nam Mau coal mines is very complicated for mechanism longwall method, specialy was cause of is the cause of difficulties in moving hydraulic support, so it is necessary to have appropriate reform solutions for the support equipment to operate effectively. The result of dynamic field measurements at the site shows that the maximum support pressure is from 5 to 10 m in front of the mechanism longwall. The coal seam area is located close to the working face due to the influence of the support pressure and beyond the durable limit which was in an unconsolidated state, so it is possible to cause the mirror landslide and topping out. Calculation results show that the distance of 15 m against advance reinforcement at the junction of the furnace head and foot furnace as designed. The results of the study of the distribution of surrounding longwall face pressure, length of longwall need longer 40 meters.

scholarly journals Research on Stress Distribution Characteristics for Uniquely Shaped Roadway with Hard Roof in Steeply Inclined Coal Seam and Support Technology of Reducing Vibration Impact

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Junhui Zhang ◽  
Hui Chen ◽  
Xiuzhi Shi ◽  
Weiming Guan ◽  
Xiaolong Sun
Keyword(s):  
Stress Distribution ◽  
Coal Seam ◽  
Rock Burst ◽  
Coal Mine ◽  
Surrounding Rock ◽  
Additional Stress ◽  
The Road ◽  
Hard Roof ◽  
Original Rock ◽  
The Impact

This paper presents a comprehensive study of the stress distribution and stability analysis of a uniquely shaped roadway having a steeply dipping hard roof. The coal seam and its roof have a certain impact tendency, which is the internal condition of rock burst. The syncline tectonic stress causes the original rock stress to reach a higher level. The large amount of coal produced in the coal mine and the large movement range of the upper strata cause the huge mining additional stress around the stope. The impact load caused by “cantilever beam” fracture of hard roof can induce and strengthen rock burst. Its engineering geological setting encompasses the mining process and surrounding rock conditions of No. 6 Coal Seam in the 2130 coal mine of Xinjiang. Numerical simulations with theoretical analysis and field measurements investigated a proposed new truss combined support scheme for implementation. A comparison was made of the differences in the state parameters of the road under the new and old support conditions. The application of the new combined support technology changed the form of the stress distribution around the road. Apart from the displacements of the two coal sidewalls, the new support system notably reduced the displacement of roof and floor by 67.8% and 83.6%, respectively. After the implementation of the new support scheme, the frequency of the original rock burst in the working face is greatly reduced, the surrounding rock control and field application effects also remained good, and personnel and equipment safety and production plan have a good guarantee.

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