scholarly journals Comprehensive Evaluation of the Mining Geological Conditions of the No. 72 Coal Seam in the Sunan Mining Area in Anhui Province, China

Author(s):  
Zhi-gen ZHAO ◽  
Cheng-juan YING
2012 ◽  
Vol 594-597 ◽  
pp. 1338-1342
Author(s):  
Qing Hai Li ◽  
Ren Shu Yang ◽  
Wei Ping Shi

In first mine of Chagannaoer, 2# coal seam, the mainly mined out layer, was 22.00m thickness in average. In order to meet the requirements of production ability, the mine was planned to apply mining technology of fully mechanized caving. Good or bad of top coal’s caving was an important prerequisite which decided the mining technology of top coal caving could be chosen or not. Due to lack of producing mines in this region and no experience to refer, we simulated the mining process of 2# coal seam using numerical software of FLAC3D, and gained evolution laws of stress and displacement of top coal and overlying strata and expansion laws of plastic zone. Through analysis, we got that the top coal damaged seriously and the top coal could be caved smoothly. Relying on the geological conditions of site, we verified the simulated results with method of fuzzy comprehensive evaluation. Combined with the research results, we decided that 2# coal seam’s caving was better and was convenient for top coal caving, so it was suitable for caving mining in 2# coal seam in first mine of Chagannaoer.


2012 ◽  
Vol 204-208 ◽  
pp. 3-9
Author(s):  
Qi Lang Le

Based on the research of interlayer-gliding structures in Panbei and Panji No.1 coal mine that are located in the each wing of Panji anticline, the Panji mining area is divided into 9 main interlayer-gliding areas and 29 sub-regions. The results indicate that the interlayer-gliding structures mainly developed in the anticline wings, which show obvious symmetry at the type and distribution. The types of the interlayer-gliding structures are fault-sliding and corrugation type in the wings and fracture type in the core area. The type and manifestation of the interlayer-gliding structures also show symmetry in the similar depth. From up to down, the interlayer-gliding type show obvious regularity that fracture type is mainly developed in the shallow area, down is fault-sliding type and corrugation type is mainly developed in the deep or the interchange of the faults. Take fuzzy comprehensive evaluation method to evaluate the inter-gliding structure in west area of Panji No.1 coal mine. The results showed that the results from using fuzzy comprehensive assessment were similar with the results exposed by coal mine. Good effects were obtained for predicting the development intensity of the seam-gliding structure in deep unmined areas in combination with geological conditions of coal mine, providing references for production arrangement of coal mine.


2012 ◽  
Vol 616-618 ◽  
pp. 402-405 ◽  
Author(s):  
Hong Chun Xia ◽  
Guo Sheng Gao ◽  
Bin Yu

According to the specific geological conditions in themulti-layer worked-out areas of Yongding coal seam, by the methods of integration of theoretic analysis, numerical value calculation and so on, we studied movement law of Overlaying Strata and influence of coal pillar in Coal seam mining, obtained the basic law of the overlying strata movement in multiplayer, provides a theoretical basis for the safe and efficient exploitation of the success of multiplayer. Many mining area in China is mining of closed distance coal seam group, By the impact of coal seam in the overlying, face and the tunnel roof structure will be different injury in sub-coal seam mining, Roof structure has changed greatly, even damage and easily take the roof leakage, When the the goaf communication with the overlying coal seams, caused by the induced secondary disasters such as face air leakage, Therefore, exploitation of the law of motion of the overlying strata in the multiplayer is a pressing problem. Exploitation multiplayer seam few theoretical and technical foundation at home and abroad, affecting the validity of the mining, rationality. although a lot of research on theory and technology of coal mining over the years[1~5], But it was not able to an overall comprehensive analysis of upper goaf adjacent goaf and overlying the coal pillar and present mining face, create a dynamic structural mechanics model, which is likely to cause the occurrence of disasters.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Haixiao Lin ◽  
Feng Yang ◽  
Zhengzheng Cao ◽  
Yue Wang ◽  
Xiaojian Jiao

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.


2017 ◽  
Vol 14 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Guan Yingbin ◽  
Wang Xinghen ◽  
Guo Shengwen

Purpose The purpose of study is to develop methods for damage prevention and production safety. Design/methodology/approach In this study, water aquifers in various districts of the Merlin Temple coal-mining area number 3-1 were examined using a fuzzy comprehensive evaluation. Using FLAC-3D software, a three-dimensional numerical model based on the geological conditions of the first mining area was built to produce a numerical simulation of the fissure-zone and caving development in the area. Findings The simulation results, together with the traditional empirical formula, were used to produce a contour map of the distribution of these characteristics. This enabled areas to be classified according to various safety factors. Originality/value On the basis of the water richness in the area, coal-roof aquifers and the safety factors of different districts, as well as comprehensive coal-roof water-flow conditions and their associated dangers could be better understood.


2019 ◽  
Vol 98 ◽  
pp. 01034 ◽  
Author(s):  
Mingjun Liu ◽  
Changlai Xiao ◽  
Xiujuan Liang

In this study, a hydrochemical investigation was conducted in Shuangliao city to identify the hydrochemical characteristics and the quality of groundwater using descriptive statistics and correlation matrices. And on that basis, combined with Analytic hierarchy process (AHP), an improved two-level fuzzy comprehensive evaluation method is used to evaluate the groundwater quality. The results indicate that the major cations and anions in groundwater are Ca2+ and HCO3-, respectively. The chemical types are mainly HCO3—Ca type water, some areas are complicated due to the influence of human activities. The evaluation results show that the water quality in the area is mostly III type water, and the groundwater quality in some areas is IV or V water due to the influence of primary geological conditions or human activities. The groundwater quality in the East Liaohe River Valley and Shuangliao urban area is relatively poor, and in the northwest part which is the saline alkali soil area is also relatively poor.


2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Zhao Chunhu ◽  
Jin Dewu ◽  
Wang Qiangmin ◽  
Wang Hao ◽  
Li Zhixue ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li Shen ◽  
Qiang Zeng

AbstractIn the present paper, with using diverse methods (including the SEM, the XRD, the TPO, the FTIR, and the TGA) , the authors analysed samples of the major coal seam in Dahuangshan Mining area with different particle sizes and with different heated temperatures (from 50 to 800 °C at regular intervals of 50 °C). The results from SEM and XRD showed that high temperature and high number of pores, fissures, and hierarchical structures in the coal samples could facilitate oxidation reactions and spontaneous combustion. A higher degree of graphitization and much greater number of aromatic microcrystalline structures facilitated spontaneous combustion. The results from TPO showed that the oxygen consumption rate of the coal samples increased exponentially with increasing temperature. The generation rates of different gases indicated that temperatures of 90 °C or 130 °C could accelerate coal oxidation. With increasing temperature, the coal oxidation rate increased, and the release of gaseous products was accelerated. The FTIR results showed that the amount of hydroxide radicals and oxygen-containing functional groups increased with the decline in particle size, indicating that a smaller particle size may facilitate the oxidation reaction and spontaneous combustion of coal. The absorbance and the functional group areas at different particle sizes were consistent with those of the heated coal samples, which decreased as the temperature rose. The results from TGA showed that the characteristic temperature T3 declined with decreasing particle size. After the sample with 0.15–0.18 mm particle size was heated, its carbon content decreased, and its mineral content increased, inhibiting coal oxidation. This result also shows that the activation energy of the heated samples tended to increase at the stage of high-temperature combustion with increasing heating temperature.


2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao

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.


2015 ◽  
Vol 1092-1093 ◽  
pp. 1394-1397
Author(s):  
Guang Chun Fei ◽  
Yi Fan Yu ◽  
Ke Qiang Hua

The Dongzhongla Pb-Zn deposit, a newly-discovered medium-sized deposit, is located in the north margin of the eastern Gangdese, central Lhasa block. Based on the analysis of the ore-forming geological conditions in this deposit, sulfur isotope of this deposit were analyzed, and S isotopic equilibrium temperature of mineral pairs (sphalerite and galena) were calculated. This study has shown that the sulfur isotopic equilibrium temperature of sphalerite and galena in Dongzhongla Pb-Zn deposit ranged from 185℃ to 296℃. It indicated that the equilibrium temperature decreased gradually from the skarn stage to sulfide stage. The equilibrium temperature can be used as the reference of metallogenic temperature for Dongzhongla Pb-Zn deposit. DongzhongLa deposit is the typical type of skarn Lead-zinc deposit. East of the Dongzhongla mining area is the priority exploration area.


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