Feasibility Analysis of Upward Mining of Coal Seam Group in a Coal Mine

2019 ◽  
Vol 07 (01) ◽  
pp. 15-20
Author(s):  
晓明 闫
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Feasibility Analysis ◽  
Upward Mining

scholarly journals Vertical stress and stability of interburden over an abandoned pillar working before upward mining: a case study

2018 ◽  
Vol 5 (8) ◽  
pp. 180346 ◽  
Author(s):  
Jinwen Bai ◽  
Guorui Feng ◽  
Shanyong Wang ◽  
Tingye Qi ◽  
Jian Yang ◽  
...  
Keyword(s):  
Coal Seam ◽  
Initial Stress ◽  
Central Region ◽  
Coal Mine ◽  
Mechanical Analysis ◽  
Field Monitoring ◽  
Vertical Stress ◽  
Plastic Damage ◽  
Residual Coal ◽  
Upward Mining

Upward mining of the residual coal seam over an abandoned pillar working is one of the effective measures to alleviate the contradiction between limited resources and increased consumption. Interburden stability over an abandoned pillar working plays a significant role in guaranteeing the safety of upward mining; however, it has not yet been extensively studied and understood. In this study, the vertical stress of the interburden over an abandoned pillar working was first investigated. The mechanical model of the interburden was established and the damage conditions were analysed. Then, the stability of the interburden over 38502 abandoned workings in Baijiazhuang coal mine was determined by mechanical analysis and field monitoring. The results show that: (i) Vertical stress of the interburden over abandoned mining zones is clearly lower than the initial stress, indicating the existence of a de-stressed effect. Moreover, vertical stress of the interburden over residual coal pillars is greater than the initial stress, which is the evidence of a stress concentration effect. (ii) The interburden over an abandoned pillar working should be regarded as an elastic rectangular plate supported by generalized Kelvin bodies in mechanical modelling. (iii) The interburden over abandoned mining zones may experience two damage stages. In the first stage, initial plastic damage appears at the central region of interburden. In the second stage, the plastic damage evolves from the central point to the surrounding areas. (iv) The mechanical analysis and field monitoring both indicate the initial damage occurred at the central region over 38502 abandoned workings in Baijiazhuang coal mine before upward mining. Related rock control measures should be implemented in that region to guarantee the safe mining of the residual coal seam.

scholarly journals A Method for Determining Feasibility of Mining Residual Coal above Out-Fashioned Goaf under Variable Load: A Case Study

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yuxia Guo ◽  
Honghui Yuan ◽  
Xiaogang Deng ◽  
Yujiang Zhang ◽  
Yunlou Du ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Coal Pillar ◽  
New Method ◽  
System Model ◽  
Variable Load ◽  
Residual Coal ◽  
Seam Mining ◽  
Suspended Roof ◽  
Upward Mining

Out-fashioned goaf is the protective structure for mining the upper residual coal, and its stability is the core problem in mining the upper residual coal. According to the upward mining demand for No. 5 coal seam above the out-fashioned goaf in Baizi Coal Mine, a new method is proposed to determine the upward mining safety. According to the analysis of the actual situation of the mine, the coal pillar and suspended roof in the out-fashioned goaf are taken as the objects. Furthermore, a “coal pillar-suspended roof” system model based on the variable load induced by abutment pressure of upper coal seam mining is established. After the mechanical model was solved, the parameter acquisition method of the model was established. The basic parameters of Baizi Coal Mine were considered to determine the feasibility of mining residual coal above out-fashioned goaf. And the effects of variable load on the coal pillar and suspended roof stability were analyzed. The results show that the upper No. 5 coal seam in Baizi Coal Mine can be mined safely. Compared to the traditional method, which simplifies all the upper loads to uniform loads, the new method is safer. The system stability of the suspended roof and coal pillar is influenced by “a/L” and “L.” Axial stress curves of the coal pillar and suspended roof appear nearly parabolic with “a/L” varying. Their maximum values are obtained when the “a/L” value is around 0.5∼0.6. In this situation, the combination structure is most easy to to be damaged. The ratio q′/q has a linear relationship with all stresses of the system model. The failure sequence of the system model is determined by analyzing the relationship between the tensile strength of the suspended roof and compressive strength of the coal pillar. This study provides a reference case for coal resources upward mining under similar conditions.

Feasibility Analysis of Safety Mining Underlying Limestone Water in Yuandian Coal Mine

2012 ◽  
Vol 256-259 ◽  
pp. 454-457
Author(s):  
You Ling Fang ◽  
Yu Long Chen
Keyword(s):  
Coal Seam ◽  
Coal Mine ◽  
Mining Area ◽  
Feasibility Analysis ◽  
Targeted Prevention ◽  
Limestone Aquifer ◽  
Mining Conditions ◽  
Prevention And Treatment ◽  
Water Filling ◽  
Safe Mining

The No.10 coal seam in the first mining area of Yuandian Coal Mine lies in Taiyuan Group limestone aquifer with rich water, the underlying limestone water is an important danger for mine water-filling. To ensure the safety of mining, it is necessary to study and analyze the mining conditions. On this basis, with the design of targeted prevention and treatment of water, we achieve the purpose of safe mining.

Phosphorus minerals in tonstein; coal seam 405 at Sośnica-Makoszowy coal mine, Upper Silesia, southern Poland

2013 ◽  
Vol 63 (2) ◽  
pp. 271-281 ◽  
Author(s):  
Magdalena Kokowska-Pawłowska ◽  
Jacek Nowak
Keyword(s):  
Trace Elements ◽  
Coal Seam ◽  
Mineral Composition ◽  
Coal Mine ◽  
Chemical Compositions ◽  
Coal Basin ◽  
Upper Silesia ◽  
Southern Poland ◽  
Basin Area

Abstract Kokowska-Pawłowska, M. and Nowak, J. 2013. Phosphorus minerals in tonstein; coal seam 405 at Sośnica- Makoszowy coal mine, Upper Silesia, southern Poland. Acta Geologica Polonica, 63 (2), 271-281. Warszawa. The paper presents results of research on tonstein, which constitutes an interburden in coal seam 405 at the Sośnica- Makoszowy coal mine, Makoszowy field (mining level 600 m), Upper Silesia, southern Poland. The mineral and chemical compositions of the tonstein differ from the typical compositions described earlier for tonsteins from Upper Silesia Coal Basin area. Additionally, minerals present in the tonsteins include kaolinite, quartz, kaolinitised biotite and feldspars. The presence of the phosphatic minerals apatite and goyazite has been recognized. The presence of gorceixite and crandallite is also possible. The contents of CaO (5.66 wt%) and P2O5 (6.2 wt%) are remarkably high. Analysis of selected trace elements demonstrated high contents of Sr (4937 ppm) and Ba (4300 ppm), related to the phosphatic minerals. On the basis of mineral composition the tonstein has been identified as a crystalline tonstein, transitional to a multiplied one.

Reasonable Entry Layout of Lower Seam in Multi-Seam Mining Based on Numerical Simulation

2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Coal Seam ◽  
Coal Mine ◽  
Abutment Pressure ◽  
Surrounding Rock ◽  
Geological Conditions ◽  
Seam Mining

Based on the geological conditions of 6# coal seam and 8# coal seam in Xieqiao Coal Mine, to determine reasonable entry layout of lower seam in multi-seam mining, alternate internal entry layout, alternate exterior entry layout and overlapping entry layout were put forward and simulated by FLAC3D. Then stress distribution and displacement characteristics of surrounding rock were analyzed in the three ways of entry layout, leading to the conclusion that alternate internal entry layout is a better choice for multi-seam mining, for which makes the entry located in stress reduce zone and reduces the influence of abutment pressure of upper coal seam mining to a certain extent,. And the mining practice of Xieqiao Coal Mine tested the results, which will offer a beneficial reference for entry layout with similar geological conditions in multi-seam mining.

Feasibility Analysis on Implement of Freeze Roadway Cooling Technology in Coal Mine of Heilongjiang Province

2012 ◽  
Vol 204-208 ◽  
pp. 1830-1833
Author(s):  
Jing Zhou ◽  
Xi Ming Liu ◽  
Xian Li Qin ◽  
Shu Ren Xing
Keyword(s):  
Constant Temperature ◽  
Coal Mine ◽  
Soil Layer ◽  
Reference Value ◽  
Frozen Soil ◽  
Feasibility Analysis ◽  
Geological Condition ◽  
Heilongjiang Province ◽  
Geographical Position ◽  
Cooling Technology

Freeze roadway cooling technology is delivering cold quantity to cooling underground face by storage cooling energy in strata, and the effect of storaging cold is critical. The geographical position and geological condition of coal mine in Heilongjiang Province has remarkable characteristics. The feasibility of freeze roadway cooling measure was demonstrated on temperature, geothermal, constant temperature strata and frozen soil layer, etc. by analyzed its advantage adequately. The measure provides a new idea which suits the native situation for prevent the heat-harm in coal mine, it also has the realistic reference value and is worth popularizing.

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