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- Keyword
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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 961 - 990 of 1799
Full-Text Articles in Engineering
Heat Conduction Performance And Transfer Mechanism Of Sand-Barite Powder Backfill Materials, Jia Hailiang, Zhu Zixian, Zhou Yang, Sun Qiang
Heat Conduction Performance And Transfer Mechanism Of Sand-Barite Powder Backfill Materials, Jia Hailiang, Zhu Zixian, Zhou Yang, Sun Qiang
Coal Geology & Exploration
The ground source heat pump of buried pipeline is a major form of shallow thermal energy utilization, and the thermophysical properties of backfill materials, especially the thermal conductivity, are the key factors affecting the heat transfer efficiency of the heat pump system. In this paper, the variation law of thermal conductivity of the sand-barite powder samples at different barite powder mixing ratio (volume fraction) and saturation was studied. The mechanism of improving the thermal conductivity of backfill materials with barite powder was revealed based on the macroscopic and microscopic experiments such as stereoscope and nuclear magnetic resonance analysis. In addition, …
Tomography Method For Adjacent Channel Frequency Shift Of Transmitted In-Seam Waves, Tian Han, Wu Rongxin, Hu Ze’An, Yang Qiaonan
Tomography Method For Adjacent Channel Frequency Shift Of Transmitted In-Seam Waves, Tian Han, Wu Rongxin, Hu Ze’An, Yang Qiaonan
Coal Geology & Exploration
In-Seam Seismic is one of the main detection methods for small geological structures in the coal mining working face. In this method, the energy attenuation feature of in-seam waves is mainly utilized. In case of any significant geological anomaly or receivers coupling difference in coal working face, the energy distribution of the in-seam wave at different frequency bands will be significantly affected, and the stability and accuracy of in-seam wave detection results will be decreased. Using the centroid frequency change features of the in-seam wave signals for inversion imaging is an innovative, effective method. However, for this method, there are …
Development Of Rescue Truck-Mounted Drilling Rig In Ground Emergency, Fan Dong, Zou Zujie, Wang Ruize, Lu Feifei, Liu Qi, Wang Hejian
Development Of Rescue Truck-Mounted Drilling Rig In Ground Emergency, Fan Dong, Zou Zujie, Wang Ruize, Lu Feifei, Liu Qi, Wang Hejian
Coal Geology & Exploration
Ground drilling is an effective means to rescue the person trapped underground in case of accident in a mine. The rescue truck-mounted drilling rig is an ideal model for mine accident rescue due to its adaptability to a variety of drilling technologies and the advantages of wide formation adaptability, high mobility and strong accident handling capacity. In view of the shortcomings of domestic truck-mounted drilling rig in the construction of life support hole and large-diameter relief well, ZMK5550TZJF50/120 truck-mounted drilling rig was developed. Specifically, the large capacity power head adaptable to various technologies was developed, adopting the design of installation …
Adaptive Electro-Hydraulic System Of Zmk5550tzjf50/120 Truck-Mounted Drilling Rig With Wob Adaptive Control Function, Chang Jianghua, Zhao Liang, Lu Feifei, Wang Longpeng, Yang Jiangbo
Adaptive Electro-Hydraulic System Of Zmk5550tzjf50/120 Truck-Mounted Drilling Rig With Wob Adaptive Control Function, Chang Jianghua, Zhao Liang, Lu Feifei, Wang Longpeng, Yang Jiangbo
Coal Geology & Exploration
The truck-mounted drilling rig is an ideal model for rescue drilling construction due to its strong mobility and wide process adaptability. The traditional truck-mounted drilling rig adopting the mode of hydraulic control and hydraulic drive has the problems of non-intuitive displaying of control parameters and many pipelines, which is hard to achieve the closed-loop control. In case of drilling into the complex formations, the response speed of the driller is often difficult to adapt to changes in working conditions, which is not conducive to the drilling safety. In order to meet the requirements of safety and high automation of rescue …
Table Of Contents, The Editors
Application Of Pneumatic Dth Hammer In Drilling Rescue Of Mine Accidents, Zhao Jiangpeng, Hao Shijun
Application Of Pneumatic Dth Hammer In Drilling Rescue Of Mine Accidents, Zhao Jiangpeng, Hao Shijun
Coal Geology & Exploration
As an efficient percussive rock breaking tool, pneumatic down-the-hole (DTH) hammer has played an important role in drilling rescue of mine accidents at home and abroad. Herein, the technical characteristics of pneumatic DTH hammer were described from the points of rock breaking mechanism, structure type, drilling method and specification, and the reverse circulation type and its characteristics of pneumatic DTH hammer were emphatically analyzed. Besides, the application of forward circulation drilling of pneumatic DTH hammer and the combined deviation correction drilling of pneumatic DTH hammer and mud screw in small diameter drilling, as well as the research progress of pneumatic …
Formation Mechanism Of Coalbed Methane In Dafosi Mine Field, Huanglong Coalfield, Liu Kaide, Yao Kaiwen, Chen Nengyuan, Fan Zhangqun, Li Shujia, Zheng Han, Yue Wenping, Li Xiaolong
Formation Mechanism Of Coalbed Methane In Dafosi Mine Field, Huanglong Coalfield, Liu Kaide, Yao Kaiwen, Chen Nengyuan, Fan Zhangqun, Li Shujia, Zheng Han, Yue Wenping, Li Xiaolong
Coal Geology & Exploration
Dafosi mine field is a typical low-rank coalbed methane (CBM) field in Binchang mining area of Huanglong Jurassic. There are many coalbed methane wells in the field, but few researches are performed on the formation mechanism of coalbed methane. Thus, it is of great guiding significance to clarify the geochemical characteristics and formation mechanism of coalbed methane (CBM) in the mine field, which could provide important basis for the analysis on productivity difference of high- and low-yield CBM Wells. For this reason, the samples of drained gas at the wellhead of six CBM wells, 22 coal samples of No.4 coal …
Digital Twin Technology Of Geological Information In Mining And Excavation Working Face, Li Peng, Cheng Jianyuan
Digital Twin Technology Of Geological Information In Mining And Excavation Working Face, Li Peng, Cheng Jianyuan
Coal Geology & Exploration
The mine geology transparency is the basis for the intelligent coal mine construction. 3D geological modeling is an important measure for realizing the mine geology transparency. In the geological modeling of the previous working face, there are problems including the discrepancy between the interpolation algorithm and the geological law, the low fusion level of the multi-source heterogeneous geological data, and the seldom coupling between the coal mine production equipment and the geological information. The concept of the digital twin of the geological information about coal mine working face was proposed, the discrete smooth interpolation (DSI) algorithm was adopted, and the …
Key Technologies And Equipment Of Quickly And Safely Building Life Support And Rescue Channel In Mine Disaster, Tian Hongliang, Zou Zujie, Hao Shijun, Cao Ming, Zhou Guanghua, Huang Yong, Gu Hairong, Wang Lei
Key Technologies And Equipment Of Quickly And Safely Building Life Support And Rescue Channel In Mine Disaster, Tian Hongliang, Zou Zujie, Hao Shijun, Cao Ming, Zhou Guanghua, Huang Yong, Gu Hairong, Wang Lei
Coal Geology & Exploration
In case that persons are trapped underground as a result of shaft and roadway damage due to a major disaster accident in a mine, the most effective way of rescue is to construct the rescue channel in a safely and efficient manner. The rescue channel is divided into the underground and ground types. Building a large diameter rescue channel through the collapsed section is the most direct way if underground construction conditions are available. However, if no underground construction conditions are available or it is prone to secondary disasters, it is necessary to drill small diameter rescue holes on the …
Key Technologies Of Surface Efficient Life Support Hole Forming For Mine Rescue, Zhang Biao, Kang Yuguo, Huang Yong, Zhang Ming, Zhou Guang, Ren Yingju, Liu Jianlin, Gao Ke, Zhao Yan
Key Technologies Of Surface Efficient Life Support Hole Forming For Mine Rescue, Zhang Biao, Kang Yuguo, Huang Yong, Zhang Ming, Zhou Guang, Ren Yingju, Liu Jianlin, Gao Ke, Zhao Yan
Coal Geology & Exploration
The surface life support hole, as the support channel for the trapped people underground, is one of the important ground emergency rescue schemes for the situation with some people trapped underground due to mine accidents. Under the complex conditions of the rescue area, including easy collapse, easy leakage, large water inflow and inclined formation, the single hole forming process has the problems such as poor ground adaptability matching, low comprehensive drilling efficiency and difficult roadway penetration, which cannot meet the requirements of rescue. In order to form an efficient drilling technology system for life support holes and improve the response …
Research Progress Of Lifting Equipment For Large-Diameter Borehole Rescue, Gu Hairong, Shan Zenghai, Wang Longpeng, Shao Tao, Zou Zujie, Gao Ziyu
Research Progress Of Lifting Equipment For Large-Diameter Borehole Rescue, Gu Hairong, Shan Zenghai, Wang Longpeng, Shao Tao, Zou Zujie, Gao Ziyu
Coal Geology & Exploration
Rescue through large-diameter relief well is an efficient method of mine emergency rescue. The lifting equipment of large-diameter relief well is used to lift the trapped personnel safely and reliably to the surface through the large-diameter relief well. It is the key equipment in the rescue system of large-diameter relief well. With the rescue technology of large-diameter relief well gradually recognized in the industry, the lifting equipment of large-diameter relief well has developed considerably, forming the fixed and mobile types of lifting equipment and multiple technical routes. Besides, important progress has been made in the research on the lifting equipment …
Research On Key Technology Of Pipe Jacking Drilling Equipment For Large-Diameter Rescue Borehole Of Coal Mine, Wang Lei, Zhu Yuqin, Zhang Weina, Liu Hao, Zhao Wenbo, Yang Chuang, Wang Guanxiong
Research On Key Technology Of Pipe Jacking Drilling Equipment For Large-Diameter Rescue Borehole Of Coal Mine, Wang Lei, Zhu Yuqin, Zhang Weina, Liu Hao, Zhao Wenbo, Yang Chuang, Wang Guanxiong
Coal Geology & Exploration
In order to solve the rescue problem of collapsed roadways in coal mines and improve the drilling speed of large-diameter rescue boreholes, the construction method of large-diameter borehole with pipe jacking technology was proposed. Specifically, the collapsed rock mass was crushed and the slag was removed by pushing the connectable pipe joints and cutter heads with the main jacking equipment arranged in the chamber, so as to form a rescue channel composed of jacked pipes at last. A composite cutter head with large opening under the condition of collapsed rock mass was developed, which is composed of 10 cutters, 10 …
Research And Application Of Synchronous Self-Balancing Feed System For Rescue Truck-Mounted Drilling Rig, Zou Zujie, Tian Hongliang, Liu Qingxiu, Chang Jianghua, Liu Qi, Zhu Guodong
Research And Application Of Synchronous Self-Balancing Feed System For Rescue Truck-Mounted Drilling Rig, Zou Zujie, Tian Hongliang, Liu Qingxiu, Chang Jianghua, Liu Qi, Zhu Guodong
Coal Geology & Exploration
Truck-mounted drilling rig is the core equipment of ground drilling rescue in mine accidents, and it has played an important role in all the successful rescues at home and abroad. However, the feed system, as the main actuator of the truck-mounted drilling rig, exposes the problems of restricted passability of the whole machine due to the long working stroke, difficult maintenance of the positioning wheel train, poor movement synchronization of the double cylinder, guide rail wearing caused by the partial load of power head, and the delay of pulling force displayed by the hydraulic gauge during its service. ZMK5550TZJF50/120 rescue …
Research And Application Of Multi-Source Information Detection Technology For Drilling Rescue Of Mine, Zheng Xuezhao, Sun Ziyu, Guo Jun, Zhang Duo, Chen Gang, He Qinjian
Research And Application Of Multi-Source Information Detection Technology For Drilling Rescue Of Mine, Zheng Xuezhao, Sun Ziyu, Guo Jun, Zhang Duo, Chen Gang, He Qinjian
Coal Geology & Exploration
Drilling rescue of mine is a new type of rescue technology. In order to quickly and accurately obtain the information on drilling channel, the location distance of the trapped person and the characteristics of the gas environment in the disaster area during rescue, as well as to realize the two-way video and audio communication between the trapped person underground and the rescue commander on the ground, theoretical research and technical development were conducted with the technical methods such as multi-source information fusion, dual-stream network video service, edge computing, intrinsically-safe circuit control, and ultra-wideband radar. Meanwhile, two key technologies were proposed: …
Distribution Characteristics Of Trace Elements In Different Density Fractions Of High-Germanium Coal From Wulantuga, Inner Mongolia, China, Duan Piaopiao, Wang Wenfeng, Ma Mengya
Distribution Characteristics Of Trace Elements In Different Density Fractions Of High-Germanium Coal From Wulantuga, Inner Mongolia, China, Duan Piaopiao, Wang Wenfeng, Ma Mengya
Coal Geology & Exploration
The exploitation and utilization of critical metals in coal measures is of great significance to alleviate the shortage of strategic mineral resources in China. In addition to the critical metal germanium (Ge), the low-rank coal from Wulantuga Coal Mine of Shengli Coalfield in Inner Mongolia, China is enriched with the toxic elements Be, F, As, Hg, Sb and W. Considering the extraction and utilization of key metals and environmental protection, the coal in the study area must be washed. As shown in the previous study, flotation is relatively good for the removal of As, Sb and W inWulantuga coal, but …
Main Influencing Factors For Regional Pre-Grouting Technology Of Water Hazard Treatment In Coal Seam Floor And Efficient Hole Arrangement, Hu Weiyue, Zhao Chunhu, Lyu Hanjiang
Main Influencing Factors For Regional Pre-Grouting Technology Of Water Hazard Treatment In Coal Seam Floor And Efficient Hole Arrangement, Hu Weiyue, Zhao Chunhu, Lyu Hanjiang
Coal Geology & Exploration
Regional advance grouting transformation and reinforcement of water conducting formation and aquifer is the main technical means to prevent and control the karst water hazards in the coal seam floor of North China type coalfields. Herein, analysis was conducted for the general application mode of the regional advance grouting transformation and reinforcement for water hazard treatment in the thin and thick limestone layers in the coal seam floor based on the basic mine hydrogeological principle of the application of regional advance grouting transformation technology. In the analysis, consideration was given to the hydrogeological structure of the coal seam floor, the …
Key Pretreatment Technologies For Coalbed Gas Bioengineering And Review On Their Mechanism Of Action, Bao Yuan, Chang Jianing, Liu Xiangrong, Xia Daping, Wang Yaya
Key Pretreatment Technologies For Coalbed Gas Bioengineering And Review On Their Mechanism Of Action, Bao Yuan, Chang Jianing, Liu Xiangrong, Xia Daping, Wang Yaya
Coal Geology & Exploration
Coalbed gas bioengineering (CGB) is a new technology for the purpose of realizing the clean utilization of coal resources and the enhanced recovery of coalbed gas. To explore the key characteristics of the pretreatment technologies of CGB, hydrocarbon generation potential and its mechanism of action, conclusion and summary was made for various pretreatment technologies herein. Meanwhile, the pretreatment technologies were divided into three types according to the action mode of coal (organic matter) and bacteria (microorganism): microflora optimization and improvement, coal dissolution and oxidation, and biological stimulation and synergy. By comparing the capability of coal to generate methane through microbial …
Subgrade Subsurface Anomalous Body Full-Waveform Inversion Based On Ground-Penetrating Radar, Hu Leilei, Chen Kang, Huang Dejun, Yang Rong
Subgrade Subsurface Anomalous Body Full-Waveform Inversion Based On Ground-Penetrating Radar, Hu Leilei, Chen Kang, Huang Dejun, Yang Rong
Coal Geology & Exploration
The hidden dangers of road collapse and underground voids are usually difficult to notice and easy to occur in sudden. They have caused huge losses in people's lives and properties. Therefore, the detection and analysis of road collapse and underground voids are crucial. The ground-penetrating radar (GPR) is the main method for detecting the hidden dangers of urban road collapse currently by virtue of its high accuracy, high efficiency, continuous non-destructiveness and real-time imaging. A convolution type objective function FWI algorithm was proposed to solve the problem of the lower inversion accuracy and practicability caused by the inaccurate estimation of …
Status And Prospect Of Harmless Disposal And Resource Comprehensive Utilization Of Solid Waste Of Coal Gangue, Wang Yutao
Coal Geology & Exploration
A large amount of coal gangue generated during coal production and processing is piled up on the surface, which not only causes land occupation and soil erosion, but also causes geological disasters such as landslides and debris flows. So it has a serious impact on the ecological environment of the mining area. The cumulative stockpile of coal gangue in China has exceeded 6 billion tons, accounting for 13000 hectares of land. In 2020, the output of coal gangue in China is 729 million tons, the comprehensive utilization is 526 million tons, and the comprehensive utilization rate is 72.2%. At present, …
Research On Drill Pipe Pose Recognition Technology Based On Monocular Vision, Ma Bin, Peng Guangyu
Research On Drill Pipe Pose Recognition Technology Based On Monocular Vision, Ma Bin, Peng Guangyu
Coal Geology & Exploration
As a key technology in the field of intelligent drilling equipment, automatic drill pipe loading and unloading technology restricts the automation and intelligent development of underground drilling equipment in coal mines. The existing drill pipe automatic loading and unloading system mainly relies on the mechanical structure and proximity switches for positioning, which has the problem of poor positioning accuracy and low automation. To solve this problem, a drill pipe pose recognition algorithm based on monocular vision technology was proposed. The camera was used to capture the image containing the cooperative target, and the relative distance and posture between the camera …
Design And Application Of Pump-Free Double Channel Mechanical Hole Enlarging Bit For Gas Penetration In Middle Hard Coal Seam, Gao Xiaoliang, Shao Guojie, Yang Huwei
Design And Application Of Pump-Free Double Channel Mechanical Hole Enlarging Bit For Gas Penetration In Middle Hard Coal Seam, Gao Xiaoliang, Shao Guojie, Yang Huwei
Coal Geology & Exploration
In borehole enlarge drilling, it is necessary to adjust the flow of mud pump to switch drilling and borehole enlarging state, and the control effect is not ideal. To improve the precision of the borehole enlarging technology while drilling machinery control, a pump-free double channel mechanical borehole enlarging drill bit was developed, which equiped with dual channel to form a complete set of double channel drill pipe and double channel water device. Two sets of individual waterways were designed, annulus water way for cooling bit and carry out rock powder, and center water way is used to control the opening …
Research And Application Of Integrated Fracturing Fluid System For Unconventional Natural Gas In Coal Measures, Xu Dong, Wang Yubin, Bai Kunsen, Zhu Weiping, Liu Chuanqing, Li Bing, He Pengbo
Research And Application Of Integrated Fracturing Fluid System For Unconventional Natural Gas In Coal Measures, Xu Dong, Wang Yubin, Bai Kunsen, Zhu Weiping, Liu Chuanqing, Li Bing, He Pengbo
Coal Geology & Exploration
To solve the problems of poor application flexibility and non-adjustable performance of the current fracturing fluid system in unconventional natural gas of coal measures, an integrated fracturing fluid system is researched. In this study, the experimental evaluation was performed for the viscosity increase, drag reduction, sand suspension, temperature and shear resistance, gel breaking, additive compatibility, anti-swelling and surface tension of the integrated fracturing fluid system based on three kinds of integrated thickeners in combination with the field clay stabilizer, cleanup additive and gel breaker. Meanwhile, the field application effect of integrated fracturing fluid was analyzed. The results show that: the …
Svm-Based Sensitivity Zoning Of Subsidence Disaster Development In The Underground Coal Mining Areas, Xue Yong’An, Zou Youfeng, Zhang Wenzhi, Zhang Mingmei, Liu Guangchun
Svm-Based Sensitivity Zoning Of Subsidence Disaster Development In The Underground Coal Mining Areas, Xue Yong’An, Zou Youfeng, Zhang Wenzhi, Zhang Mingmei, Liu Guangchun
Coal Geology & Exploration
At present, there is no fixed way to predict the sensitive zones of subsidence disaster development in underground coal mining areas, and the prediction result of sensitive zones has a great uncertainty. Herein, the subsidence disaster in Xishan area of Taiyuan City, Shanxi Province was taken as the research object. Totally 4 types of kernel SVM based prediction model for sensitivity zoning of subsidence disaster were constructed with the methods of GIS spatial analysis, statistical analysis and Support Vector Machine (SVM) in combination, taking the subsidence disaster data checked and recorded in 2012 and 2014 as the modeling and verification …
Table Of Contents, The Editors
Study On Mechanical Mechanism Of Roof Fracture Evolution In Deep Stope With Variable Face Length, Wang Xinfeng, Lu Mingyuan
Study On Mechanical Mechanism Of Roof Fracture Evolution In Deep Stope With Variable Face Length, Wang Xinfeng, Lu Mingyuan
Coal Geology & Exploration
Irregular coal seam mining is easy to cause the problems such as roof stress concentration and abnormal ground pressure behavior. In order to explore the roof fracture law and the structural evolution characteristics of stope with variable length, the roof structure models with four types of boundary conditions were established and analyzed using the small-deflection thin plate bending theory in view of the geometric characteristics and mechanical causes of the abrupt stope with the inclined length of working face changing from small to large in various mining stages. Meanwhile, the roof fracture law and macro-mechanical response were analyzed by MATLAB …
Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying
Occurrence Law Of Coal Seam Gas Under Influence Of Normal Fault Zone In Coal Measures, Xiao Peng, Wu Mingchuan, Shuang Haiqing, Han Kai, Gao Zhen, Cheng Yueying
Coal Geology & Exploration
The coal measure fault zone generated by the superimposition of the polytropic movement and multiple structure has important effects on the coal seam gas occurrence. The method of combining the geologic analysis, COMSOL Multiphysics numerical simulation and field data monitoring was adopted to analyze the interaction relations between the stress distribution characteristics and faults of the normal fault zone in the coal measure, study the coal seam permeability variation characteristics influenced by the normal fault zone in the coal measure, and simulate the gas migration status and concentration distribution condition after the formation of the normal fault zone. The coal …
Research On Permeability Model Of Coal Reservoir Along Producing Wellbores, Jia Lidan, Zhang Lin, Li Bobo, Wu Xuehai, Gao Zheng, Wang Zhonghui, Fu Jiale
Research On Permeability Model Of Coal Reservoir Along Producing Wellbores, Jia Lidan, Zhang Lin, Li Bobo, Wu Xuehai, Gao Zheng, Wang Zhonghui, Fu Jiale
Coal Geology & Exploration
Permeability is an important parameter to characterize gas flow. In order to ensure the safe and efficient gas drainage, it is necessary to explore the evolution characteristics of coal reservoir gas seepage at different positions from the producing wellbores. However, the effective stress, the gas adsorption/desorption capacity of coal matrix and the temperature of coal reservoir are constantly changing with the gas drainage, and even the drainage damage may occur, which makes the gas migration behavior in coal seam extremely complicated. In order to explore the seepage characteristics of coal reservoir gas during gas drainage, the space-time evolution function of …
Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei
Occurrence Modes And Stepwise Chemical Extraction Experiment Of Lithium In No.20 Coal Seam In Pu’An Mining Area, Guizhou Province, Cheng Chen, Song Yang, Zang Jingkun, Cheng Wei
Coal Geology & Exploration
Lithium (Li) is an important energy metal, and the global demand for Li has grown rapidly in recent years. The discovery of coal-associated Li deposits in China proves that coal mines may serve as a potential alternative of Li resources. No.20 coal seam in Pu’an mining area in Guizhou province of China was selected as the study object. The basic properties, mineral composition, elemental composition, and occurrence modes of Li of the raw coal and six density-graded samples (obtained through a float-sink test) were determined by using coal proximate analysis, optical microscope, X-Ray fluorescence spectroscopy (XRF), inductively coupled plasma mass …
Numerical Simulation On Evolution Law Of Overburden Fractures And Surface Cracks In Crossing Ditch Mining Of Shallow Coal Seam, Wei Jiangbo, Wang Shuangming, Song Shijie, Sun Qiang
Numerical Simulation On Evolution Law Of Overburden Fractures And Surface Cracks In Crossing Ditch Mining Of Shallow Coal Seam, Wei Jiangbo, Wang Shuangming, Song Shijie, Sun Qiang
Coal Geology & Exploration
Crossing ditch mining of shallow coal seam is common in northern Shaanxi mining area, which seriously threatens the safe production and the sound ecological development. The mining-induced overburden fractures and surface cracks are developed as a result of the extension and expansion of microcracks in rock mass. In order to more systematically study the evolution law of overburden microcracks in crossing ditch mining of shallow coal seam, a numerical model of particle flow in coal mining was established with the Particle Flow Code (PFC) numerical simulation platform according to the field ditch profile and borehole data under the background of …
Experimental Study On Stress Relaxation Characteristics Of Soft Dredger Fill Under Uu Triaxial Shear, Yang Aiwu, Yang Shaopeng, Qi Jiejie
Experimental Study On Stress Relaxation Characteristics Of Soft Dredger Fill Under Uu Triaxial Shear, Yang Aiwu, Yang Shaopeng, Qi Jiejie
Coal Geology & Exploration
Stress relaxation often occurs in the saturated soft clay with poor water permeability under the actual working condition at fast construction speed (fast loading rate), which brings huge hidden dangers to the safe operation of engineering practice. Herein, the unconsolidated undrained triaxial shear test was performed based on the soft dredger fill in Tianjin Binhai using the WF stress path triaxial instrument, and the influence law of such factors as the different initial strain, confining pressure, shear rate, sampling depth and structural properties of the soft dredger fill on its stress relaxation characteristics was analyzed accordingly. According to the test …