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- Numerical simulation (87)
- Coalbed methane (47)
- Coal mine (39)
- Ordos Basin (31)
- Gas drainage (28)
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- Deep learning (27)
- Permeability (27)
- Pore structure (27)
- Coalbed methane (CBM) (25)
- Deep coalbed methane (24)
- Hydraulic fracturing (23)
- Tar-rich coal (23)
- Directional drilling (21)
- Underground coal mine (20)
- Coal (17)
- Deep coalbed methane (CBM) (17)
- Qinshui Basin (15)
- Horizontal well (14)
- Open-pit coal mine (14)
- Rock burst (14)
- Shale gas (13)
- Underground coal gasification (UCG) (13)
- Fracture (12)
- Machine learning (12)
- Mine water (12)
- Prospect (12)
- Fractal dimension (11)
- Helium (11)
- Intelligent mining (11)
- Microstructure (11)
- Publication Year
Articles 1531 - 1560 of 1799
Full-Text Articles in Engineering
Mineralogical Characteristics And Genesis Of The Illite In Jurassic Coal Of The Jingxi Coalfield, North China, Huang Bo, Zheng Qiming, Shi Songlin
Mineralogical Characteristics And Genesis Of The Illite In Jurassic Coal Of The Jingxi Coalfield, North China, Huang Bo, Zheng Qiming, Shi Songlin
Coal Geology & Exploration
In order to study the indicating effect of illite for coalification and sedimentary environments, the Jurassic coal seam gangue in Jingxi coalfield of North China was taken as the research object. X-ray diffraction(XRD) and X-ray fluorescence(XRF) were used to determine the mineral composition and chemical composition of the gangue sandwiched in the coal seam gangue. The mineralogical characteristics and genesis of illite in the gangue were studied. The results indicated that the intra-seam partings are mainly composed of illite, chlorite and quartz, followed by small amount of calcite and albite. The illite has an average proportion of 62.92%. According to …
Changes Of Petrographic Characteristics And Quality Of Contact-Metamorphosed Coals In The Datong Coalfield, Ma Hongtao, Song Xiaoxia, Li Kaijie, Zhao Jingui, Zhang Tianguang, Liu Jianping
Changes Of Petrographic Characteristics And Quality Of Contact-Metamorphosed Coals In The Datong Coalfield, Ma Hongtao, Song Xiaoxia, Li Kaijie, Zhao Jingui, Zhang Tianguang, Liu Jianping
Coal Geology & Exploration
Igneous intrusions in the Datong coalfield caused a considerable amount of contact metamorphosed coal, reducing the industrial value of coal. The effect of a dike in roadway 5222 in Tashan coal mine was determined from analysis of 16 samples collected near the intrusive body. Microscopic and macroscopic observation, proximate and ultimate analysis were used to determine the petrographic characteristics. The results demonstrate that contact-metamorphosed coal experienced significant thermal alteration during intrusive event. Microscopically, various natural coke microstructures, such as mosaic structure, flow structure and pyrolytic carbon were formed under excess heat; instant heating for coals resulted in the elevation of …
Creep Acoustic Emission And Fractal Characteristics Of Coal Rock Under High Temperature Pre-Damage, Shi Hongcai
Creep Acoustic Emission And Fractal Characteristics Of Coal Rock Under High Temperature Pre-Damage, Shi Hongcai
Coal Geology & Exploration
The thermal damage and triaxial creep acoustic emission experiments of coal samples at different temperatures were carried out to investigate and analyze the mechanical characteristics of coal and rock after high temperature pre-damage. The results show that the thermal damage of coal and rock increases exponentially with the increase of temperature; the brittle-ductile failure characteristics of coal and rock appear at lower temperature(≤200℃) and the accelerated creep characteristics are not obvious; the brittle-brittle failure characteristics of coal and rock appear at higher temperature(＞200℃) and the accelerated creep characteristics are more obvious; the value of steady creep rate is between pre-damage …
Progress In Research Of In-Seam Seismic Exploration, Guo Yinjing, Ju Yuanyuan, Fan Xiaojing, Zhang Jianhua
Progress In Research Of In-Seam Seismic Exploration, Guo Yinjing, Ju Yuanyuan, Fan Xiaojing, Zhang Jianhua
Coal Geology & Exploration
after long-term development and improvement, the in-seam seismic(ISS) technology has achieved relatively reliable results in detecting the internal structural development of the coal seam, the thickness variation of the coal seam, and the distribution pattern of the pinch. In order to comprehensively and systematically understand the ISS technology and promote the development of the ISS technology, the status of the ISS technology is reviewed. First, the principle of ISS is briefly described. Then, according to the process of ISS, according to the steps of source excitation, signal acquisition, preprocessing, signal extraction, data processing and analysis, the working principles and methods …
Directional Drilling Technology And Equipment Of Pneumatic Screw Motor In Soft Seam, Zhang Jie, Wang Yi, Huang Hanjing
Directional Drilling Technology And Equipment Of Pneumatic Screw Motor In Soft Seam, Zhang Jie, Wang Yi, Huang Hanjing
Coal Geology & Exploration
Aiming at the drilling problems of shallow depth, uncontrollable trajectory and blind area of extraction in soft coal seam, the directional drilling technology of pneumatic screw motor was invented, and the directional drilling equipment consisting of pneumatic screw motor, narrow structure directional drilling rig and MWD system were formed. The air directional drilling technology and hole-completion technology were studied and developed. The technology of drilling and hole-completion solves the problem of long-distance safe drilling and hole protection of directional drilling along soft coal seam. The technology has been successfully tested in a coal mine, Huainan, with 30 test boreholes with …
Collapses Of Loess At The Front Of The Emei Tableland In The Yuncheng Basin And Their Major Geological Controlling Factors, Li Zhenhong, Jiang Boyu, Dong Xiaopeng, Yang Yong, Cui Jiawei, Gong Wangbin
Collapses Of Loess At The Front Of The Emei Tableland In The Yuncheng Basin And Their Major Geological Controlling Factors, Li Zhenhong, Jiang Boyu, Dong Xiaopeng, Yang Yong, Cui Jiawei, Gong Wangbin
Coal Geology & Exploration
There developed a lot of collapse areas at the front of Emei tableland in Yuncheng Basin, especially around Xinzhuang village. Their evolution process and trend are pivotal issues for evaluating the possibility, time and location of geological hazards. Based on the geological survey in the shallow surface, combining the interpretation of remote sensing data and three-component resonance imaging technique, the surface ground evolution process of the loess collapse area for the past ten years and the present interior structure were summarized. First of all, the front of Emei tableland lies in the transition zone from loess to lacustrine deposits. Therefore, …
Numerical Simulation Of Propagation Law Of Pore-Fracture Under Uniaxial Stress, Guo Xiucheng
Numerical Simulation Of Propagation Law Of Pore-Fracture Under Uniaxial Stress, Guo Xiucheng
Coal Geology & Exploration
in order to study the law of crack propagation under different pore-fracture conditions, the crack propagation process, acoustic emission law and stress-strain curve under different crack inclination angle and different heterogeneous coefficient were numerically simulated by using RFPA software. At the same time, the results are compared with the experimental results. The results show that the cracks of the intact specimen are produced along the shear direction, while the cracks of the specimens with pores occur along the side of the crack tip and the orifice. The secondary cracks in horizontal direction and bifurcation at the prefabricated crack tip or …
Joint Correction Method Of Errors Of Mwd Inclinometer In Underground Coal Mine, Qiao Meiying, Wang Bo, Xiao Xuejun, Xu Chengkuan, Yan Shuhao
Joint Correction Method Of Errors Of Mwd Inclinometer In Underground Coal Mine, Qiao Meiying, Wang Bo, Xiao Xuejun, Xu Chengkuan, Yan Shuhao
Coal Geology & Exploration
In order to reduce the error of measuring the drilling attitude angle parameter of MWD inclinometer in coal mine, a mathematical model of error compensation based on recursive least squares was established, the joint correction method of ellipsoid fitting method, dot product invariance method and rotation plane fitting method were used in the error compensation correction for MWD inclinometer. Numerical simulation experiment and double-axis turntable experiment were carried out on the developed MWD inclinometer, error compensation correction of experimental data was conducted with joint correction method, the maximum absolute errors of pitch angle and azimuth angle before correction are 4.7° …
Table Of Contents, The Editors
The Potential Of Clean Utilization Of Coal Resources In Main Coalfields Of Henan Province, Zhao Mingzhen
The Potential Of Clean Utilization Of Coal Resources In Main Coalfields Of Henan Province, Zhao Mingzhen
Coal Geology & Exploration
In order to systematically analyze the distribution characteristics of the main harmful elements in coal in different coalfields of Henan Province and assess the potential of clean utilization of coal resources, through systematic collection of coal quality data of 12 coalfields and uniform sampling for test, the average content of 11 harmful elements in each coalfield was obtained. The weighted scale index method of generalized contrast was used to calculate the comprehensive index I of the clean potential of coal resources and assess the clean utilization potential of coal resources. The conclusion that the clean quality of coal resources in …
Petrographic, Quality Characteristics And Clean & Efficient Use Of Jurassic Coal In Ningdong Coalfield, Du Fangpeng, Luo Zheng, Qiao Junwei, Zhao Xiaochen, Tan Furong, Li Congcong, Fan Qi
Petrographic, Quality Characteristics And Clean & Efficient Use Of Jurassic Coal In Ningdong Coalfield, Du Fangpeng, Luo Zheng, Qiao Junwei, Zhao Xiaochen, Tan Furong, Li Congcong, Fan Qi
Coal Geology & Exploration
Jurassic coal resources in Ningdong coalfield are huge, also play important role in coal resource development and utilization in Ningxia. For the purpose of clean and efficient use of Jurassic coal in Ningdong coalfield, coal quality and petrographic characteristics were analyzed based on coalfield exploration data. The results show that Jurassic coal in Ningdong coalfield is characterized by very low to low ash, very low to low sulfur content, low phosphorus, low arsenic, low fluorine and high heating value, these characters indicate that Jurassic coal is clean power coal. Besides that, it has medium to high volatile, higher H/C, lower …
Characteristics Of Tectonic Evolution Of Carboniferous-Permian Coal Measures In The North-Central Qinshui Basin, Lin Zhongyue, Liu Kang, Wei Yingchun
Characteristics Of Tectonic Evolution Of Carboniferous-Permian Coal Measures In The North-Central Qinshui Basin, Lin Zhongyue, Liu Kang, Wei Yingchun
Coal Geology & Exploration
By restoring the paleo-tectonic and sedimentary environment of coal accumulation period, combining with the tectonic stress field and subsidence history, the formation process of Late Paleozoic coal measures in the North-central Qinshui basin and the influence of multi-stage tectonic movement on the occurrence of coal measures minerals were comprehensively analyzed. It is considered that during the C-P coal-accumulating period, the NE-trending sedimentary depression controlled the present tectonic framework of the basin. During Indosinian period, the basin underwent rapid subsidence and formed coal measures gas under the action of deep metamorphism. During Yanshanian period, the basin was destroyed by compression, the …
The Microscopic Fabric Characteristics Of Biaxial Compression Test Of Typical Argillaceous Siltstone In Badong Formation, Xiao Zunqun, Wang Xin, Tang Dongsang, Dong Qiongying, Jiang Yinan, Yang Kai, Cao Tongtong, Deng Zhen
The Microscopic Fabric Characteristics Of Biaxial Compression Test Of Typical Argillaceous Siltstone In Badong Formation, Xiao Zunqun, Wang Xin, Tang Dongsang, Dong Qiongying, Jiang Yinan, Yang Kai, Cao Tongtong, Deng Zhen
Coal Geology & Exploration
Based on the indoor biaxial compression test of argillaceous siltstone, a numerical model of PFC2D particle flow was established. The model considered the particle shape of the argillaceous siltstone samples. Five typical particle shapes were selected according to the scanning electron microscope, and the circular particles were selected. A stable numerical sample of a given porosity was randomly generated together. The parallel bond contact model was selected between the particles, and the elastic modulus, Poisson’s ratio and peak stress were selected to calibrate the meso-parameters of the saturated and natural argillaceous siltstone samples under different confining pressures, and then the …
Application Of Simulink In Transient Process Analysis Of Transient Electromagnetic Field, Liu Shilei, Zhang Ying, Yue Jianhua
Application Of Simulink In Transient Process Analysis Of Transient Electromagnetic Field, Liu Shilei, Zhang Ying, Yue Jianhua
Coal Geology & Exploration
In order to analyze the distribution and variation law of transient electromagnetic field intuitively, the response equations of transient electromagnetic field under different damping states are theoretically derived, including a modeled transient process of transient electromagnetic field via Simulink. The equivalent circuit modules of excitation current, transmitting loop, geological anomaly body, receiving coil and their mutual inductance modules are developed. The influence of inductance, distributed capacitance and resistance on the equivalent circuit of transmitting and receiving loops are systematically studied. The results indicate a direct determination of the excitation waveform characteristics of the transient electromagnetic field based on the damping …
Research And Application Of Mine Distributed Seismic Advance Detection System, Dou Wenwu, Wei Jinshan, Jiao Yang, Yang Gaofeng, Ji Zeyu
Research And Application Of Mine Distributed Seismic Advance Detection System, Dou Wenwu, Wei Jinshan, Jiao Yang, Yang Gaofeng, Ji Zeyu
Coal Geology & Exploration
The mine distributed seismic advance detection system is a set of equipment for detecting the heading geological structure of the mine tunnel. The system is based on the seismic reflection theory. The geologic anomaly is determined by the distributed geophones or the distributed excitation of the source. In order to improve the prediction and prediction accuracy of the structure during coal mining, the distributed observation system and the hole capsule detectors are used for data acquisition to improve the sensitivity of the equipment, the negative apparent velocity principle is used to exclude the interference of the lateral and rear geological …
Ato Mode-Based Modular Platform Development Of Variable Luffing Crawler Drilling Rig Used In Underground Coal Mine, Song Haitao, Yao Ningping, Yao Yafeng, Han Jian, Peng Tao
Ato Mode-Based Modular Platform Development Of Variable Luffing Crawler Drilling Rig Used In Underground Coal Mine, Song Haitao, Yao Ningping, Yao Yafeng, Han Jian, Peng Tao
Coal Geology & Exploration
With the continuous popularization of customized crawler rigs in coal mines, the variety and specifications of crawler rigs have been further refined, diversified and complicated, and the modular platform of variable luffing crawler rigs has been successfully developed. The four key steps in the development of modular platform were analyzed: the construction of modular platform, the rational division and development of modular components, the integration and development of modular components, the modular customization model for customers based upon the proposed ATO-based model. The application results show that the establishment of the variable luffing crawler rig modular platform shortens respond to …
Development Situation And Prospect Of Luffing Mechanism Of Drilling Rig In Underground Coal Mine, Yao Yafeng, Yao Ningping, Peng Tao
Development Situation And Prospect Of Luffing Mechanism Of Drilling Rig In Underground Coal Mine, Yao Yafeng, Yao Ningping, Peng Tao
Coal Geology & Exploration
The luffing mechanism of drilling rig is used to adjust the opening parameters of the borehole, that is, azimuth angle, inclination angle, and height. According to the structural differences of different types of drilling rig and the construction characteristics of borehole in underground coal mine, this paper summarizes the adjustment requirements to opening parameters and proposes the research goal, which can rapidly and accurately adjust the parameters of the borehole and safeguard the stability of drilling construction. It is concluded that the luffing mechanism of drilling rig in underground coal mine has overall characteristics of small size, large adjustment range …
Key Technology For Rapidly Drilling Large Diameter Destressing-Drillhole In Rockburst Coal Seam, Wei Hongchao, Wang Yi, Wang Bo
Key Technology For Rapidly Drilling Large Diameter Destressing-Drillhole In Rockburst Coal Seam, Wei Hongchao, Wang Yi, Wang Bo
Coal Geology & Exploration
In order to improve the hole forming rate and construction efficiency of large diameter destressing-drillhole in rockburst mine, based on the analysis of the stress characteristics of coal rock in rockburst coal mine, the dynamic instability characteristics of destressing-drillhole and the construction features, the key points for drilling large diameter destressing-drillhole, the efficient discharge of cuttings and fast drilling/lifting were proposed. Combining with the discharge of cuttings method by dual-power, the technology and equipment for rapidly drilling large diameter destressing-drillhole in rockburst coal seam were formed finally after the design and optimization of key equipment, drilling tools, technology and drilling …
Foam Drilling Technology And Application For Broken Soft Coal Seam In Underground Coal Mine, Ji Qianhui, Dong Mengmeng, Liu Jianlin, Shi Lei
Foam Drilling Technology And Application For Broken Soft Coal Seam In Underground Coal Mine, Ji Qianhui, Dong Mengmeng, Liu Jianlin, Shi Lei
Coal Geology & Exploration
Aiming at the limitation of middle pressure air drilling for gas drainage in soft and broken coal seam, such as limited drill cutting removal capacity, and dust pollution, foam drilling technique research in underground coal mines was carried out. CFD simulation of the flow field during the drilling process was conducted to obtain the optimized drilling tool structure parameters for efficient drill cutting transportation. Optimal structural parameters of wide-blade milled auger drill rod with the number of heads 3, the groove width 26 mm, and the pitch 110 mm were determined. A foam perfusion system suitable for underground coal mining …
Development Of Small Diameter Hydraulic Agitator With Cable For Directional Drilling In Underground Coal Mine, Wang Li, Xu Baolong, Wang Yi, Huang Hanjing, Jia Mingqun, Ma Bin
Development Of Small Diameter Hydraulic Agitator With Cable For Directional Drilling In Underground Coal Mine, Wang Li, Xu Baolong, Wang Yi, Huang Hanjing, Jia Mingqun, Ma Bin
Coal Geology & Exploration
Aiming at the problems of large drilling pressure, low drilling efficiency and limited hole depth caused by the backing effect of drill string during deep hole directional drilling in underground coal mine, the technical idea of using hydraulic agitator was proposed. The ø89 mm small diameter hydriculic agitator was designed based on valve principle, the exciting force, excitation frequency were identified, and the cabled sub was developed. The performance parameters of hydraulic agitator with disc spring and cylindrical spring were tested. The results show that when the flow rate of 300 L/min the disc spring hydraulic agitator has the maximum …
Distribution And Resource Prospect Of Metal Ore Spots(Deposits) In Coal Of Different Coal-Forming Ages In Northern China, Ning Shuzheng, Huang Shaoqing, Zhang Li, Huang Wenhui, Cao Daiyong, Yuan Jianjiang, Zhang Jianqiang, Zhu Shifei, Yan Deyu, Liu Kang
Distribution And Resource Prospect Of Metal Ore Spots(Deposits) In Coal Of Different Coal-Forming Ages In Northern China, Ning Shuzheng, Huang Shaoqing, Zhang Li, Huang Wenhui, Cao Daiyong, Yuan Jianjiang, Zhang Jianqiang, Zhu Shifei, Yan Deyu, Liu Kang
Coal Geology & Exploration
In some cases, metals such as germanium, gallium, lithium and rare earth elements can be enriched in coal, which is an important potential source of these metals. There are abundant coal resources in northern China, and a large number of coal-metal ore spots(deposits) have been found, and the distribution of these ore spots(deposits) shows certain temporal and spatial characteristics: Metals in Permo-Carboniferous coal occur mainly as gallium and lithium-enriched ore spots, mainly are distributed in the northern coalfields of North China coal bearing regions and mining areas such as Pingshuo and Jincheng in Shanxi Province; the metal enrichment in Early-Middle …
Discussion And Application Of Geological Evaluation Index Of Scarce Coal Injected Into Blast Furnace, Qiao Junwei, Li Zhengyue, Chen Meiying, Lyu Jun’E
Discussion And Application Of Geological Evaluation Index Of Scarce Coal Injected Into Blast Furnace, Qiao Junwei, Li Zhengyue, Chen Meiying, Lyu Jun’E
Coal Geology & Exploration
Coal injected into blast furnace can reduce the use of coke, is an important technical measure to reduce the production cost and improve the economic benefit of modern blast furnace. From the influential factors of quality of coal injected into blast furnace and on the basis of evaluation of quality of high-quality coal and scarce coal, the geological evaluation indexes and the grading parameters of scarce coal injected into blast furnace were discussed. The evaluation indexes of coal quality for blast furnace are divided into process index and economic index. Process index is the key index to determine whether coal …
Solid-Liquid Migration Of Molybdenum In Stone Coal And Coal Ash In Southern Shaanxi, Zhang Weiguo, Li Huantong, Wang Feng, Yang Fu, Teng Jinxiang
Solid-Liquid Migration Of Molybdenum In Stone Coal And Coal Ash In Southern Shaanxi, Zhang Weiguo, Li Huantong, Wang Feng, Yang Fu, Teng Jinxiang
Coal Geology & Exploration
Molybdenum is a typical environmental sensitive element, and also a potential rare metal element. In order to find out the content characteristics of molybdenum in raw stone coal and coal ash and the migration rule between solid and liquid, stone coal and coal ash in southern Shaanxi Province were selected as the research object, and the molybdenum content in samples was analyzed by ICP-MS. To analyse the leaching rate of molybdenum from stone coal and coal ash in four different liquids, pure water, scid, alkaline and mine drainage were selected to simulate soaking experiment. The results show that the content …
Causes Of Anomaly Of Rare Earth Elements Of Seam 2 Of Yan’An Formation In The Northern Margin Of Ordos Basin And Its Geological Significance, Yang Yi, Lyu Dawei, Zhang Jianqiang, Wu Dun
Causes Of Anomaly Of Rare Earth Elements Of Seam 2 Of Yan’An Formation In The Northern Margin Of Ordos Basin And Its Geological Significance, Yang Yi, Lyu Dawei, Zhang Jianqiang, Wu Dun
Coal Geology & Exploration
The cause of rare earth elements(REE) anomalies in No.2 coal seam of the Yan’an Formation in the northern margin of the Ordos basin has been controversial. This paper takes Dahaize coal mine, Yulin area with well developed No.2 coal as an example to analyze REE, mineralogical characteristics of coal and partings, and to reveal the causes of anomaly of REE by Inductive Coupled Plasma Mass Spectrometry(ICP-MS) and Scanning Electron Microscopy(SEM). The results show that the total rare earth element(∑REE) concentration in the coal samples ranges from 3.71 to 46.21 μg/g. Light rare earths elements(LREE, La-Eu) are more abundant than heavy …
Numerical Simulation Of Layer-Crossing Propagation Behavior Of Hydraulic Fractures At Coal-Rock Interface, Li Haozhe, Jiang Zaibing, Shu Jiansheng, Fan Yao, Du Tianlin
Numerical Simulation Of Layer-Crossing Propagation Behavior Of Hydraulic Fractures At Coal-Rock Interface, Li Haozhe, Jiang Zaibing, Shu Jiansheng, Fan Yao, Du Tianlin
Coal Geology & Exploration
Based on the analysis of coal-rock interface, the vertical propagation behavior of hydraulic fractures at coal-roof interface was studied by using finite element method. The influence of some geological and engineering factors on fracture layer-crossing behavior was analyzed. Results have shown that in-situ stress and shear strength of coal-rock interface are the two main factors affecting the fracture propagation at the coal-rock interface. Greater vertical stress difference coefficient and interfacial shear strength make fractures more easier for crossing the interface. Meanwhile, the difference of elastic modulus and tensile strength between coal and rock has less effect on the fracture vertical …
Influencing Factors Of The Dynamic Permeability Of Cbm Reservoir And Cbm Well Drainage Control Measures, Wang Qing, Yang Fei, Gong Weicheng, Xu Tianxin, Li Yichao
Influencing Factors Of The Dynamic Permeability Of Cbm Reservoir And Cbm Well Drainage Control Measures, Wang Qing, Yang Fei, Gong Weicheng, Xu Tianxin, Li Yichao
Coal Geology & Exploration
The drainage and production control method has significant impact on the permeability of coalbed methane reservoir. Based on the main control factors of the permeability at different stages of drainage and production of coalbed methane wells, this paper puts forward targeted drainage and production countermeasures with the goal of improving the permeability. When the bottom-hole flow pressure was greater than the original reservoir pressure, the step-down velocity was between 0.08 and 0.1 MPa/d to reduce fracturing fluid and velocity-sensitive damage. When the bottom hole flow pressure was between reservoir pressure and desorption pressure, the pressure could be reduced at a …
Effect Of White Rot Fungi Pretreatment On Methane Production From Anaerobic Fermentation Of Coal, Zhang Huaiwen, Huang Song, Yan Xiatong, Zhao Shufeng, Zhang Minglu, Xia Daping
Effect Of White Rot Fungi Pretreatment On Methane Production From Anaerobic Fermentation Of Coal, Zhang Huaiwen, Huang Song, Yan Xiatong, Zhao Shufeng, Zhang Minglu, Xia Daping
Coal Geology & Exploration
To investigate the effect of white rot fungi pretreatment on methane production from anaerobic fermentation of coal, fermentation experiments of biogas production were conducted using long flame coal. The coal samples pretreated with white rot fungi were the experimental group(EG), and original untreated coal samples were the control group(CG). The COD(chemical oxygen demand) mass concentration, activity of coenzyme F420, and changes of coal morphology were measured using potassium dichromate method, ultraviolet spectrophotometry, and SEM, respectively. The results showed the following: The total gas production and conversion rate in the EG and CG were 2 322.00 mL and 5.10%, 1 330.20 …
Dynamic Evolution Law Of Water Accumulation Range In Coal Mining Subsidence Area With High-Level Groundwater, Chen Xiaoxie, Zhang Wentao, Zhu Xiaojun, Liu Hui, Zhang Min, Sun Aiguo, Yang Xiaoyu
Dynamic Evolution Law Of Water Accumulation Range In Coal Mining Subsidence Area With High-Level Groundwater, Chen Xiaoxie, Zhang Wentao, Zhu Xiaojun, Liu Hui, Zhang Min, Sun Aiguo, Yang Xiaoyu
Coal Geology & Exploration
In order to study the dynamic evolution law of the water accumulation range with high-level groundwater, the working face 1031 of Wugou coal mine was taken as the research area. Based on Landsat-8 remote sensing data, the evolution law of water accumulation range above working face 1031 during 2013-2017 was summarized and the influence of factors such as net rainfall, groundwater depth and working surface propulsion distance on the evolution of water accumulation range was analyzed. The concept of the boundary angle of the water accumulation range was proposed, and the functional relationship between the angle and the mining time …
Preparation Of Underwater Quick-Set And Expansion Polyurethane Grouting Material And Its Properties, Yang Zhu, Xue Ren, Wang Jun, Lan Zhili
Preparation Of Underwater Quick-Set And Expansion Polyurethane Grouting Material And Its Properties, Yang Zhu, Xue Ren, Wang Jun, Lan Zhili
Coal Geology & Exploration
Quick plugging and dynamic grouting technology under complex geologic conditions in mines is a technical problem in the field of grouting and one of the effective solutions is to develop new chemical grouting materials. Based on the reaction principle of polyurethane materials, we carried out the research and development on production formula of polyurethane grouting materials. By analyzing the polyurethane synthesis reaction temperature and the way of adding reagents as well as conducting contrast experiments on various auxiliaries and additives the best formula for the material was determined. It was found that the grouting material prepared by 4% nano silica …
Classification Of Hidden Faults In Coal Seam Floor And Measures For Water Inrush Prevention, Liu Zewei, Liu Qisheng, Liu Yang
Classification Of Hidden Faults In Coal Seam Floor And Measures For Water Inrush Prevention, Liu Zewei, Liu Qisheng, Liu Yang
Coal Geology & Exploration
The floor hidden faults with mine water bursting coefficient between 0.06 and 0.1 MPa/m have not been classified scientifically in combination with mining. Based on the characteristics of hidden faults in coal seam floor and the vertical relationship between the location of the top interface of the hidden fault and the " Three Underlying Belts", the hidden faults in coal seam floor are classified into three types: high, middle, and low from the perspective of mine water prevention of the floor. Through theoretical analysis and case analysis of water inrush, it is pointed out that the high hidden fault with …