Recent Patents on Thin Coal Seam Mining Equipment

2020 ◽  
Vol 13 (2) ◽  
pp. 99-108
Author(s):  
Yanxiang Wang ◽  
Daolong Yang ◽  
Bangsheng Xing ◽  
Tingting Zhao ◽  
Zhiyi Sun ◽  
...  
Keyword(s):  
Coal Seam ◽  
Underground Space ◽  
Mining Method ◽  
Mining Equipment ◽  
Coal Seams ◽  
Thin Coal Seam ◽  
Recoverable Reserves ◽  
Working Face ◽  
Geological Conditions ◽  
Seam Mining

Background:: China's thin and extremely thin coal seam resources are widely distributed and rich in reserves. These coal seams account for 20% of the recoverable reserves, with 9.83 billion tons of industrial reserves and 6.15 billion tons of recoverable reserves. Objective: Due to the complex geological conditions of the thin coal seam, the plow mining method cannot be effectively popularized, and the drum mining method is difficult to be popularized and applied in small and medium-sized coal mines, so it is necessary to find other more advantageous alternative mining methods. Methods: The equipment integrates mining operations, conveying operations, and supporting operations, and is suitable for mining short and extremely thin coal seam with a height of 0.35m-0.8m and width of 2m-20m. It has the advantages of the low body of the shearer, no additional support on the working face, and small underground space. The mining efficiency of thin coal seam and very thin coal seam can be improved and the mining cost can be reduced. Results: Thin coal seam shear mining combines mining, conveying, and supporting processes together and has the advantages of a low fuselage, no extra support required for the working face, and feasibility in a small underground space. Conclusion: The summarized mining method can improve the mining efficiency of thin and extremely thin coal seams, reduce mining costs, and incorporate green mining practices, which take both mining economy and safety into account.

The Current Situation and Developing Trend of Extremely Thin Coal Seam Mining of China

2013 ◽  
Vol 295-298 ◽  
pp. 2918-2923 ◽  
Author(s):  
Li Ming Zhang
Keyword(s):  
Coal Seam ◽  
Automatic Monitoring ◽  
Development Trend ◽  
Mining Method ◽  
Mining Equipment ◽  
Coal Seams ◽  
Existing Problems ◽  
Thin Coal Seam ◽  
Equipment Development ◽  
Seam Mining

Degree of mechanization of extremely thin coal seam mining is growing, with introducing the main mining method currently used by the different inclination of the extremely thin coal seams in China, focusing on the different mining technology and related ancillary mining equipment development status and existing problems, and discuss the extremely thin coal seam in the future to realize the remote control, automatic monitoring and unmanned mining development trend.

An innovative approach to thin coal seam mining of complex geological conditions by pressure regulation

2014 ◽  
Vol 71 ◽  
pp. 249-257 ◽  
Author(s):  
Tongbin Zhao ◽  
Zhenyu Zhang ◽  
Yunliang Tan ◽  
Chengzhong Shi ◽  
Ping Wei ◽  
...  
Keyword(s):  
Coal Seam ◽  
Innovative Approach ◽  
Pressure Regulation ◽  
Thin Coal Seam ◽  
Geological Conditions ◽  
Seam Mining

scholarly journals Control of the Internal and External Staggered Distance of Coal Mining Face to the Water-Conducting Fissures in the Overlying Strata of the Near Coal

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhiyuan Jin ◽  
Tao Peng
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Coal Mine ◽  
Calculation Formula ◽  
Coal Seams ◽  
Coal Face ◽  
Geological Conditions ◽  
Mining Face ◽  
Seam Mining ◽  
Water Proof

In Northwest China, rainfall is low, water resources are scarce, and the ecological environment is fragile. For shallow-buried and close-spaced coal seams with a thickness of upper coal bed >60∼70 m, the water-conducting fissures of the overlying rock will not penetrate the water-isolating layer after the upper coal seam is mined; the internal and external gap angles of the water-conducting fissures are not generated from the water-isolating layer. We set out to explore the critical internal and external dislocations for the second significant development of water-conducting fissures in the overlying rock after coal mining under control. A calculation model for the critical internal and external staggered distances of coal mining face in shallow-buried and close-spaced coal seams is established, the calculation formula is given, and the calculation formula for the critical seam mining ratio under the condition of internal staggered mining mode is given. Numerical simulation performed by UDEC methods: taking the overburden strata in the shallow-buried and close-spaced coal seam mining area of Shigetai Coal Mine as a prototype, it was verified that the critical internal and external offsets of the coal mining face in shallow-buried and close-spaced coal seams have a significant effect on the overlying water flow cracks in the mining of the lower coal seam. For the feasibility of developmental control, according to the engineering geological conditions of Shigetai, through the calculation method of external staggered distance, it is concluded that the distance of the open cut of the lower coal face and the upper coal face is only 21∼27 m, which is much smaller than the water barrier. It does not produce the critical distance of the water-conducting cracks. Therefore, in the process of mining the lower coal seam, the water-proof layer will produce water-conducting cracks, lose its water-proof performance, and cause water loss. This is also the cause of the water inrush accident in Shigetai Coal Mine.

scholarly journals A protective seam mining method by cutting roof with chainsaw arm machine

2020 ◽  
Author(s):  
Tiejun Kuang ◽  
Yang Tai ◽  
Bingjie Huo ◽  
Binwei Xia ◽  
Yanqun Zhang ◽  
...  
Keyword(s):  
Lower Layer ◽  
Mining Method ◽  
Coal Seams ◽  
Working Face ◽  
Protective Seam ◽  
Mining Pressure ◽  
Coal Pillars ◽  
Residual Coal ◽  
Seam Mining ◽  
Protective Seam Mining

Abstract Multiple-layered coal seams widely exist in main coal mining areas of China. When these coal seams are exploited, the pillar mining method is always employed. This leads to many coal pillars left in the upper coal seams as a protective barrier. As a result, these residual pillars will not only cause the loss of coal resources but also could trigger environmental issues and a serious of mine disasters. A theoretical model was built to analyse the effect of the residual pillars. From the theoretical model, it was found that four stress concentration areas were formed by the upper residual coal pillars. To address the issues of the residual coal pillars, Datong Coal Mine Group has developed an innovative technology of the roof cutting with a chainsaw. A new protective coal seam mining method using chainsaw roof-cutting technology is introduced. A numerical model is constructed to analyse the mining pressure distribution law in working face within the lower layer coal seam. From the numerical simulation, the new protective layer mining method could reduce about 15.2% of the advancing stress, which contributes a lot to controlling the mining pressure within the lower layer. The field measurement showed that the hydraulic support utilised at the site was at lower pressure levels, which proves the new protective seam mining method can significantly reduce the working face pressure.

Key Parts Structure Optimum Design of Plow

2012 ◽  
Vol 619 ◽  
pp. 115-118
Author(s):  
Bo Zhu ◽  
Hui Li
Keyword(s):  
Coal Seam ◽  
High Speed ◽  
Coupled Model ◽  
Strength Analysis ◽  
Mining Equipment ◽  
Thin Coal Seam ◽  
Reliable Performance ◽  
Structure Strength ◽  
Thin Seam ◽  
Seam Mining

Our country has abundant coal resources, thin seam can reserves 20% of all can be occupied. But , with adverse circumstances, thin coal seam mining has not yet been fully realized automation. Plough is a kind of mining equipment with shallow-frustum, Low mining height, multi circulation.Its simple structure in thin coal seam mining is a unique advantage. Along with the plough development to high-powered, high speed to dig, automation direction, and with its reliable performance problems appear more prominent, it is badly in need of further research and discussion. In order to improve the reliability of plough, expand the scope of use plough, this paper applied the method of virtual prototype of the plough structure strength analysis. Taking a coal company designed BT plough as project object, the joint simulation environment is been established by Pro/E,ANSYS and ADAMS.by using corresponding modal interface technology. At last rigid-flexible coupled model has been formed in ADAM.

scholarly journals Disastrous Mechanism of Water Discharge in Abandoned Gob above the Stope in Mining Extra-Thick Coal Seam

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Haixiao Lin ◽  
Feng Yang ◽  
Zhengzheng Cao ◽  
Yue Wang ◽  
Xiaojian Jiao
Keyword(s):  
Coal Seam ◽  
Water Discharge ◽  
Mining Area ◽  
Thick Coal Seam ◽  
Research Results ◽  
Key Stratum ◽  
Working Face ◽  
Geological Conditions ◽  
Induced Fractures ◽  
Seam Mining

The Datong mining area is a typical double system coal seam mining area in China, where the Jurassic and Carboniferous coal seams are mined simultaneously. The upper Jurassic coal seam has been largely mined, leaving a large amount of gob area. Besides, a large amount of harmful water is accumulated. With the exploitation of the 3-5# extra-thick coal seam in the Carboniferous system, the scope of overburden damage is greatly increasing, and the mining fracture field is further developed. Once the mining-induced fractures connect with the overlying gob, it is easy to induce the water discharge disaster. With the mining geological conditions of the 8202 working face in the Tongxin coal mine as references, the disastrous mechanism of water discharge in the abandoned gob above the stope in the mining extra-thick coal seam is researched by numerical simulation with the UDEC numerical software, and the research results are obtained. The water in the overlying gob percolates through the mining-induced fractures in the higher key layer forming a “shower” seepage pattern. The water in the above gob converges in the key fracture channel, flowing into the working face. The seepage in the fractures in the high key stratum experiences the process of increase, decrease, and stabilization, related with the stretching and extrusion deformation between the high key stratum blocks. Compared with other fractures, the flow rates in the No.2 and No.4 fractures in the far field key lay are larger, because the fractures are in the tension state, forming the “saddle-shaped” flow pattern. The influencing distance of mining-induced seepage is about 80 m in front of the working face. The research results provide a guided reference for the prediction and prevention of water discharge disaster in an abandoned gob above the stope in a mining extra-thick coal seam.

scholarly journals Distribution Law of Mining Stress of the Gob-Side Entry Retaining in Deep Mining Thin Coal Seam

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Tao Qin ◽  
Kai Ren ◽  
Chen Jiang ◽  
Yanwei Duan ◽  
Zhi Liu ◽  
...  
Keyword(s):  
Coal Seam ◽  
High Stress ◽  
Horizontal Stress ◽  
Stability Control ◽  
Vertical Stress ◽  
Boundary Line ◽  
Thin Coal Seam ◽  
Working Face ◽  
Distribution Rule ◽  
Seam Mining

In order to explore the mining pressure development rule of gob-side entry retaining during deep thin coal seam mining, FLAC3D numerical simulation is applied to analyze the stress distribution rule of gob-side entry retaining, observing the left third working face of 49# coal seam in No. 8 mining area of Xinxing Coal Mine as the research object. The results show that the working face stress field is asymmetrical which is caused by the reserved roadway and the over goaf. After roadway tunneling, features of obvious stress redistribution are formed. The vertical and horizontal stress in the coal seam develop a U-shaped distribution. The vertical stress in the roadway is less than that in the lower roadway, and the horizontal stress is half that in the lower roadway. The phenomenon of high stress “nucleation” appears and becomes more obvious in the process of working face advancing, and the nuclear body disappears after working face advanced to the boundary line. With the working surface advancing, the trend of horizontal stress of gob-side entry retaining decreases gradually and the vertical stress of gob-side entry retaining is less than the original rock stress. The research findings provide a basis for the supporting design of gob-side entry retaining in the deep thin coal seam and the stability control of surrounding rock.

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