scholarly journals Study on Efficient Utilization Technology of Coal Pillar Based on Gob-Side Entry Driving in a Coal Mine with Great Depth and High Production

2019 ◽  
Vol 11 (6) ◽  
pp. 1706 ◽  
Author(s):  
Xinyue Li ◽  
Nong Zhang ◽  
Zhengzheng Xie ◽  
Dongxu Liang ◽  
Yiming Zhao
Keyword(s):  
Renewable Resources ◽  
Coal Pillar ◽  
Great Depth ◽  
Efficient Utilization ◽  
Key Technology ◽  
Coal Resources ◽  
High Production ◽  
Efficient Recovery ◽  
Pillar Size

Improving the utilization of non-renewable resources takes a crucial position in circular economy. Gob-side entry driving technology has been widely applied in coal mines in China, such as in the Shilawusu mine (Ordos City, Inner Mongolia), here considered as a case study due to its high safety and resource-recovery rate. However, at present the complexity of coal pillar utilization makes it hard to fully master the key technology for coal pillar size design, which leads to huge waste of coal resources. Based on theoretical calculation and numerical simulation, this study analyzed the basic mechanical structure of coal pillar and the characteristics of its weakening failure, providing theoretical reference for efficient recovery of coal resources. In general, results of this study can be helpful in pursuing the efficient, hence sustainable, development of mines with Gob-side entry driving technology.

Optimization Studies on Pillar Size of Fully Mechanized Caving Face

2014 ◽  
Vol 1010-1012 ◽  
pp. 1535-1539
Author(s):  
Xian Zhi Meng
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Theoretical Calculations ◽  
Coal Pillar ◽  
Economic Benefits ◽  
Monitoring Methods ◽  
Coal Resources ◽  
Roadway Stability ◽  
Extent Of Damage ◽  
Pillar Size

By theoretical calculations, numerical simulation and field monitoring methods to analyze the stress distribution and the extent of damage of coal pillar determine a reasonable size is about 10m, can improve the recovery rate of coal resources, and to ensure the roadway stability. 10m pillar coal resources compared with the previous 20m pillar recovery increased by about 5.5%, and created tremendous economic benefits of the mine.

Support of soft rock tunnel at great depth designed by numerical modeling—A case study

2020 ◽  
pp. 619-622
Author(s):  
Hongwei Zhou ◽  
Yang Ju ◽  
Heping Xie ◽  
Geng Ma ◽  
Zhengliang Dong ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Soft Rock ◽  
Great Depth ◽  
Rock Tunnel

scholarly journals Zoning Control Technology of Gob-Side Roadway Driving with Small Coal Pillar Facing Mining in a Special Isolated Island Working Face: A Case Study

2021 ◽  
Vol 11 (22) ◽  
pp. 10744
Author(s):  
Changliang Han ◽  
Houqiang Yang ◽  
Nong Zhang ◽  
Rijian Deng ◽  
Yuxin Guo
Keyword(s):  
Control Method ◽  
Coal Pillar ◽  
Control Technology ◽  
Stability Zone ◽  
Pressure Relief ◽  
Collaborative Control ◽  
Working Face ◽  
Underground Coal Mines ◽  
Engineering Practices

The gob-side roadway in an isolated island working face is a typical representative of a strong mining roadway, which seriously restricts the efficient and safe production of underground coal mines. With the engineering background of the main transportation roadway 1513 (MTR 1513) of the Xinyi Coal Mine, this paper introduces the engineering case of gob-side roadway driving with small coal-pillar facing mining in an isolated island working face under the alternate mining of wide and narrow working faces. Through comprehensive research methods, we studied zoning disturbance deformation characteristics and stress evolution law of gob-side roadway driving under face mining. Based on the characteristics of zoning disturbance, MTR 1513 is divided into three zones, which are the heading face mining zone, the mining influenced zone, and the mining stability zone. A collaborative control technology using pressure relief and anchoring is proposed, and the differentiated control method is formed for the three zones. For the heading face mining zone, the control method of anchoring first and then pressure relief is adopted; for the mining influenced zone, the control idea of synchronous coordination of pressure relief and anchorage is adopted; for the mining stability zone, the control method of anchoring without pressure relief is adopted. Engineering practices show that the disturbance influence distance of working face 1511 on MTR 1513 changes from 110 m advanced to 175 m delay. At this time, the surrounding rock deformation is effectively controlled, which verified the rationality of the division and the feasibility of three zoning control technology. The research results can provide reference for gob-side roadway driving with small coal pillar facing mining in a special isolated island working face.

Research on Rotation Mining with Large Angle for Unequal and Fully Mechanized Mining Face

2012 ◽  
Vol 524-527 ◽  
pp. 673-676
Author(s):  
Zhi Tao Ma ◽  
Sai Jiang Liang ◽  
Yong Ping Wang
Keyword(s):  
Sustainable Development ◽  
Coal Mining ◽  
Renewable Resources ◽  
Large Angle ◽  
Engineering Practice ◽  
Mining Method ◽  
Coal Resources ◽  
Important Measure ◽  
Coal Resource ◽  
Mining Face

Coal is one of the non-renewable resources, and in our country at present also is the main source of energy. It is very important to improve the coal mining rate, to exploit and to use the coal reasonably. Saving coal resource is an important measure for our coal industries sustainable development. Because large amounts of coal under complex conditions caused by fully mechanized mining can not be mined, the rotation mining with large angle for unequal and fully mechanized mining face and its design and main parameters are introduced in this article based on an engineering practice. Using this mining method, the coal under complex condition can be mined as much as possible. It is helpful for us to improve coal mining rate and to economize coal resources.

The influence of volcanic supply on the composition of modern river sands: the case study of the Ofanto river, Southern Italy

2021 ◽  
pp. SP520-2021-89
Author(s):  
Mariano Tenuta ◽  
Paola Donato ◽  
Rocco Dominici ◽  
Rosanna De Rosa
Keyword(s):  
Volcanic Rocks ◽  
Pyroclastic Deposits ◽  
Content Type ◽  
Sedimentary Deposits ◽  
History Of ◽  
Supplementary Material ◽  
High Production ◽  
Volcaniclastic Deposits ◽  
Pyroclastic Fall

AbstractThe Ofanto river drains volcanic rocks from the Monte Vulture, lacustrine-fluviolacustrine deposits associated with the same volcano and sedimentary deposits of the Southern Apennines and the Bradanic foredeep sequences. Comparing the modal composition of river sands and the outcrop area of different lithologies in the different sub-basins, an over-concentration of the volcaniclastic fraction, mainly represented by loose crystals of clinopyroxene, garnet and amphibole, is shown. This has been related to the preferential erosion of pyroclastic deposits, characterized by high production of sand-sized loose minerals, together with the carbonate lability and the low sand-sized detritus production from claystones and marls. The occurrence of volcaniclastic components upstream of Monte Vulture can be explained with a contribution from the lacustrine-fluviolacustrine deposits outcropping in the upstream sector or from pyroclastic fall deposits of Monte Vulture and/or Campanian volcanoes. This research shows that the volcanic record in the fluvial sands of the Ofanto river comes from weathering and sorting processes of volcaniclastic deposits rather than of the lavas building the main edifice. Therefore, caution must be taken during paleoenvironmental and paleoclimatic reconstructions when relating the type and abundance of the volcanic component in sediments to the weathering stage and evolutionary history of the volcano.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5643959

scholarly journals Dynamic failure risk of coal pillar formed by irregular shape longwall face: A case study

2018 ◽  
Vol 28 (5) ◽  
pp. 775-781 ◽  
Author(s):  
Yixin Zhao ◽  
Hao Wang ◽  
Shimin Liu ◽  
Zonglong Mu ◽  
Zhiguo Lu
Keyword(s):  
Coal Pillar ◽  
Irregular Shape ◽  
Longwall Face ◽  
Dynamic Failure ◽  
Failure Risk

Simulating the impact of coal seam gas water production on aquifers

2012 ◽  
Vol 52 (1) ◽  
pp. 545 ◽  
Author(s):  
Julian Strand ◽  
Reem Freij-Ayoub ◽  
Shakil Ahmed
Keyword(s):  
Coal Seam ◽  
Electricity Production ◽  
Water Production ◽  
Hypothetical Case ◽  
Coal Seam Gas ◽  
Coal Resources ◽  
Victorian Department ◽  
Gippsland Basin ◽  
The Impact

Derived from a larger scale project, which studied geomechanical issues associated with coal seam gas (CSG) production, this paper investigates a hypothetical case study based on the Latrobe Valley, Gippsland Basin, Victoria. The paper focuses on examining aquifer water management associated with CSG production-related water extraction. As such, the paper limits itself to determining the volume of water production from a hypothetical case study area in the Latrobe Valley. A simplistic property model and methane production strategy has been used. The impact of extraction of this water on the hydraulic head in aquifers underlying the produced seams is quantified. The Latrobe Valley Depression contains 129,000 million tonnes of coal resources and is one of the world’s largest, and lowest cost, energy sources. Most of Victoria’s electricity is generated using coal from the Loy Yang, Morwell and Yallourn mines. In addition to these massive operations, significant additional coal resources are available and unallocated at this time. Opportunities exist for the continued usage of these resources for electricity production, gasification, liquefaction and other coal conversion processes, as well as solid fuel for industrial, domestic and other uses. The existence of data from the Victorian Department of Primary Industries 2003 coal resource model was the main reason for the selection of the case study, and their data was used to form a model of the stratigraphy of the Latrobe Valley. Aquifer models were simulated in MODFLOW, based on extraction figures modelled in the CSG simulator COMET3.

scholarly journals Stability of Split-Level Gob-Side Entry in Ultra-Thick Coal Seams: A Case Study at Xiegou Mine

Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 628 ◽  
Author(s):  
Junwen Zhang
Keyword(s):  
Coal Mine ◽  
Coal Pillar ◽  
Peak Stress ◽  
Coal Seams ◽  
Solid Coal ◽  
Stress Fluctuation ◽  
Pillar Mining ◽  
The Stability ◽  
Rock Specimens

Split-level longwall gob-side entry (SLGE) has been applied as a special form of small gate pillar mining (or non-coal pillar mining) in thick coal seams. The stability of the coal pillar directly affects the rationality of the layout of the SLGE. Starting from the mining-induced influence around the SLGE, this paper compares the mechanical properties of coal under different mining effects, and studies the rationality of “zero pillar” location against the Xiegou coal mine. The study shows that the key to success of the application of the SLGE is the existence of an intact zone within the triangular coal pillar in spite of double disturbances due to tunneling and coal mining extraction. Laboratory testing shows that the density and uniaxial compressive strength of rock specimens obtained from the triangular coal pillar are smaller than that from the other part of the panel which is concluded to be due to the varied degree of mining-induced influence. The numerical modeling results show that most of the triangular coal pillar is intact after extraction of the panel, and that the peak stress is located in the solid coal beyond the triangular coal pillar. The plastic zone of the triangular coal pillar is only about 1 m after the excavation of the tail gate of the next split-level panel. The physical modeling shows that the tail gate of the next panel is in the destressed zone with only a very small stress fluctuation during the extraction of the next panel. The study shows that the location of the SLGE at Xiegou coal mine is reasonable. SLGE is preferable for ultra-thick coal seams.

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