Preparation Of Underwater Quick-Set And Expansion Polyurethane Grouting
Material And Its Properties,
2020
State Key Laboratory of Safety Technology of Metal Mine, Changsha Institute of Mining Research Co. Ltd., Changsha 410012, China
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,
2020
China Coal Research Institute, Beijing 100013, China; Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp.,Xi’an 710077, China;Shaanxi Key Laboratory of Prevention and Control Technology for Coal Mine Water Hazard, Xi’an 710077, China
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 …
Application Of Mjs Construction Method In Gravel Layer And Pile Forming Difference,
2020
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp.,Xi’an 710077, China;Shaanxi Key Laboratory of Prevention and Control Technology for Coal Mine Water Hazard, Xi’an 710077, China
Application Of Mjs Construction Method In Gravel Layer And Pile Forming Difference, Zhang Yan, Tian Zenglin, Cao Haidong, Dang Yakun, Wang Hai, Li Heping, Han Qiang
Coal Geology & Exploration
During the construction of water cutoff curtain in an open-pit coal mine in China, parts of the grouting groove couldnot be constructed due to many obstacles such as overhead high-voltage wire, buried optical cable and buried drainage pipe, and MJS construction method was chosen instead to build the cutoff curtain. The results of MJS pile tests show that the quality of piles formed by this method was obviously different in the construction area of gravel layer on the east and west sides. By the methods of geological exploration, gravity penetration test and pumping test, this paper makes a comparative analysis …
Mineralogical Characteristics And Genesis Of The Illite In Jurassic
Coal Of The Jingxi Coalfield, North China,
2020
School of Resources and Environment Engineering, Henan University of Engineering, Zhengzhou 451191, China
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,
2020
College of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China
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,
2020
College of Civil Engineering and Environment, Hubei University of Technology, Wuhan 430068, China
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 …
Directional Drilling Technology And Equipment Of Pneumatic Screw
Motor In Soft Seam,
2020
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
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 …
Numerical Simulation Of Propagation Law Of Pore-Fracture Under Uniaxial Stress,
2020
Engineering and Technology Research Institute of Great Wall Drilling Engineering Co. Ltd., Panjin 124010, China
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,
2020
School of Electrical Engineering and Automation, Henan Polytechnic University, Jiaozuo 454000, China
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,
2020
China Coal Technology and Engineering Group (CCTEG)
The Potential Of Clean Utilization Of Coal Resources In Main
Coalfields Of Henan Province,
2020
No.4 Institute of Geological and Mineral Resources Survey, Henan Bureau of Geo-Exploration and Mineral Development, Zhengzhou 450000, China
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 …
Application Of Simulink In Transient Process Analysis Of Transient
Electromagnetic Field,
2020
School of Computer Science and Technology, China University of Mining and Technology, Xuzhou 221116, China
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 …
Progress Of Drilling Technologies And Equipments For Complicated Geological Conditions In Underground Coal Mines In China,
2020
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
Progress Of Drilling Technologies And Equipments For Complicated Geological Conditions In Underground Coal Mines In China, Yao Ningping, Wang Yi, Yao Yafeng, Song Haitao, Wang Li, Peng Tao, Sun Xinsheng
Coal Geology & Exploration
According to the drilling technology requirements and problems under complicated geological conditions, such as broken soft coal seam, hard rock, rockburst strata, fractured zone, water-sensitive strata, etc, the research and application of drilling technology and screen pipe protection in broken soft coal seam, comb-like directional drilling technology in broken soft coal seam, high-level directional drilling technology in complicated roof strata, full-section across-layer drilling technology of hard rock, and drilling technology for pressure relief in rockburst strata were summed. This paper puts forward the research approaches of the technology and equipment of double-pipes directional drilling and rotary directional drilling in broken …
Ato Mode-Based Modular Platform Development Of Variable Luffing Crawler
Drilling Rig Used In Underground Coal Mine,
2020
Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
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,
2020
China Coal Research Institute, Beijing 100013, China; Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
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 …
Development Of Small Diameter Hydraulic Agitator With Cable For Directional
Drilling In Underground Coal Mine,
2020
China Coal Research Institute, Beijing 100013, China; Xi’an Research Institute Co. Ltd., China Coal Technology and Engineering Group Corp., Xi’an 710077, China
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 …
Discussion And Application Of Geological Evaluation Index Of Scarce Coal
Injected Into Blast Furnace,
2020
College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China;Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi’an 710054, China
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,
2020
College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China;Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi’an 710054, China;Key Laboratory of Coal Resources Exploration and Comprehensive Utilization, Ministry of Natural Resources, Xi’an 710021, China
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 …
Petrographic, Quality Characteristics And Clean & Efficient Use Of
Jurassic Coal In Ningdong Coalfield,
2020
College of Geology and Environment, Xi’an University of Science and Technology, Xi’an 710054, China;Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation, Xi’an 710054, China
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,
2020
China National Administration of Coal Geology, Beijing 100038, China;General Prospecting Institute, China National Administration of Coal Geology, Beijing 100039, China
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 …
