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Full-Text Articles in Earth Sciences

Table Of Contents, The Editors Dec 2020

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Application Of High-Precision 3d Seismic Exploration Technology In Huainan Mining Area, Liu Jun, Zhao Wei, Han Biwu Dec 2020

Application Of High-Precision 3d Seismic Exploration Technology In Huainan Mining Area, Liu Jun, Zhao Wei, Han Biwu

Coal Geology & Exploration

In order to deeply analyze the indication of oil shale development characteristics on paleoenvironments and provide theoretical guidance for oil shale resource evaluation, the organic geochemistry and elemental geochemistry characteristics of the Neogene Zhangcun Formation oil shale in the central part of the Qinshui basin were analyzed by Rock-Eval and TOC and the paleoclimate and paleogeographic environments of the depositional period were discussed as well. The results show that the oil shale of Zhangcun Formation has the low oil content which Tar=4.15%, higher hydrocarbon potential, kerogen is of sapropel type(I1), which has relatively shallow burial depth. The element …

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Discussion On Parameters Of High Density 3d Seismic Exploration Acquisition In Coal Mining Districts, Cheng Jianyuan, Wang Qianyao, Zhu Shujie Dec 2020

Discussion On Parameters Of High Density 3d Seismic Exploration Acquisition In Coal Mining Districts, Cheng Jianyuan, Wang Qianyao, Zhu Shujie

Coal Geology & Exploration

In order to improve the light tar and gas yield, the yield distribution and composition characteristics of pyrolysis products of bituminous coal from Shaanxi Hongliulin in the nitrogen atmosphere and weak oxygen atmosphere were studied in a fixed bed reactor. The results showed that the yield of char and tar were reduced under the weak oxygen atmosphere, and the yield of CO and CO2 increased significantly, leading to the increase of total gas yield. Due to the oxidation combustion reaction, the yield of H2, CH4 and C2-C3 gradually decreased with the increase of …

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Summary Of High Density 3d Seismic Exploration In The Mining Districts Of Coal Mines In Shanxi Province, Hou Zeming, Yang Deyi Dec 2020

Summary Of High Density 3d Seismic Exploration In The Mining Districts Of Coal Mines In Shanxi Province, Hou Zeming, Yang Deyi

Coal Geology & Exploration

Based on the analysis of geological characteristics of the study area, it is considered that the geological conditions of H2S occurrence are the capping effect of dense surrounding rock on the roof and floor, the water-conducting fractured zone is unable to guide the overlying aquifer, and the low degree of coal metamorphism is not conducive to H2S adsorption, resulting in maximum H2S concentration of about 0.001 4% in the main mined coal seam 4 during the construction of Yadian mine at the north of Binchang mining area. Through the analysis of sulfur distribution, sulfate …

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Application Of Pre-Stack Denoising Technique In Full Digital High Density 3d Seismic Technique In Coal Mining Districts, Yu Jie Dec 2020

Application Of Pre-Stack Denoising Technique In Full Digital High Density 3d Seismic Technique In Coal Mining Districts, Yu Jie

Coal Geology & Exploration

Coalbed methane resource conditions and reservoir physical conditions are the basis of CBM exploration and exploitation. The geological modeling of CBM reservoir was carried out to clarify the spatial distribution of coal reservoir, and explain the difference of single well productivity, which can provide theoretical basis for selection and well drilling. This paper took Baode unit I as research object. Based on the measured data of gas content and well test permeability, the inversion model of gas content and permeability in the study area was established by using support vector machine algorithm(SVM) and transformed F-S permeability calculation formula, and the …

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Application Of Broadband And Wide Azimuth Processing Technology In Full Digital High Density Seismic Exploration In Huaibei Mining Area, Yang Guangming, Jin Xueliang, Zhang Xianxu, Zhi Min, Shan Rui Dec 2020

Application Of Broadband And Wide Azimuth Processing Technology In Full Digital High Density Seismic Exploration In Huaibei Mining Area, Yang Guangming, Jin Xueliang, Zhang Xianxu, Zhi Min, Shan Rui

Coal Geology & Exploration

During coalbed methane well drilling, the drilling fluid contaminates and blocks the pores and fractures of coal seam. In order to find out the difference of pollution degree of drilling fluid coal and the contribution rate of the pores and fractures of different scale to permeability, the coal of Changping mine was taken as the research object, the scanning electron microscopy(SEM) and the Image Pro Plus(IPP) processing technology were used, the parameters such as the average length, the average width, the total area and the total perimeter of the fractures of different scales in coal before and after contamination were …

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High Density 3d Seismic Data-Driven Comprehensive Interpretation Method Of Magmatic Intrusion Zones In Coal Seams And Its Application, Shan Rui, Zhang Guangzhong, Wang Qianyao, Yang Guangming Dec 2020

High Density 3d Seismic Data-Driven Comprehensive Interpretation Method Of Magmatic Intrusion Zones In Coal Seams And Its Application, Shan Rui, Zhang Guangzhong, Wang Qianyao, Yang Guangming

Coal Geology & Exploration

Ordovician limestone karst water is the main threatening water source for mining activities in Baode coal mine, and it is one of the main water supply sources. Ordovician limestone karst water samples were systematically collected in Baode coal mine, and the methods of correlation analysis, ion proportional coefficient, saturation index inversion simulation and Chlor-Alkali index were chosen to analyze the hydrochemical characteristics and its formation mechanism. The results showed that the water quality types of Ordovician limestone water changed from runoff zone to stagnant zone in a trend of HCO3-Na(Na·Ca)→HCO3·Cl-Na·Ca(Ca·Mg)→Cl-Na(Na·Ca). The mass concentration of each ion …

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Application Of Seismic Waveform Classification Technology In Interpretation Of Geological Abnormal Body, Cheng Yan, Zhao Pu, Lin Jiandong, Zhang Xingping Dec 2020

Application Of Seismic Waveform Classification Technology In Interpretation Of Geological Abnormal Body, Cheng Yan, Zhao Pu, Lin Jiandong, Zhang Xingping

Coal Geology & Exploration

Nalinhe No.2 coal mine is the first pair of large-scale mines in the Nalinhe mining area. The water inrush events occur from time to time due to its own complex hydrogeological conditions and strong disturbance of excavation in the initial stage of production, which has caused serious threat to the mining activity safety. Finding the source of gushing water quickly and effectively is the key to control the mine water disaster. Based on the water quality analysis of main aquifers and goaf water samples in Nalinhe No.2 coal mine, and drawing the piper trilinear nomograph water samples, the hydrogeochemical characteristics …

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X-Shaped Real Fracture Channels-Based Simulation Of Coal Seam Gas Seepage, Su Zhengrui, Wei Shanyang Dec 2020

X-Shaped Real Fracture Channels-Based Simulation Of Coal Seam Gas Seepage, Su Zhengrui, Wei Shanyang

Coal Geology & Exploration

The filling expansion mechanism and control measures of high concentration slurry in goaf is one of the difficult problems to be solved in the filling treatment of cavity goaf. Based on this, combined with the high concentration slurry transportation and rheological theory, a high concentration slurry filling process model was constructed to reveal its expansion mechanism, the dynamic and resistance calculation methods of filling expansion process were studied, the main influencing factors and control methods of filling accumulation body morphology were determined, and the theoretical results were verified by outdoor filling test.The results show that the the relative error between …

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Research Status And Thoughts For Coal Fines During Cbm Development, Wei Yingchun, Zhang Jin, Cao Daiyong, Meng Tao, Cui Maolin, Wang Anmin Dec 2020

Research Status And Thoughts For Coal Fines During Cbm Development, Wei Yingchun, Zhang Jin, Cao Daiyong, Meng Tao, Cui Maolin, Wang Anmin

Coal Geology & Exploration

Artificial freezing is a commonly used method for stopping water and providing temporary support during the excavation of saturated sand. This study on the damage characteristics of frozen soil lays the foundation for the analysis of the mechanical properties of frozen soil and the stability of frozen bodies. In order to study the damage mechanical properties of frozen sand, three-dimensional laboratory tests on frozen sand with different intermediate principal stress coefficients were carried out at -5℃. Based on the Weibull random distribution of micro element failure of frozen soil, the Drucker-Prager strength criterion was invoked as the statistical distribution variable, …

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Characteristics And Monitoring Method Of The Trajectory Of The Radial Cbm Well, Xin Kai, Ji Changjiang, Xiao Chun Dec 2020

Characteristics And Monitoring Method Of The Trajectory Of The Radial Cbm Well, Xin Kai, Ji Changjiang, Xiao Chun

Coal Geology & Exploration

The in-situ stress of 3-1 coal seam in Hongqingliang coal mine was measured by hollow core inclusion measurement, and distribution characteristics of in-situ stress field were obtained in order to solve the problem of serious deformation in mining roadway. Fault structures of grade Ⅰ-Ⅴ in Hongqingliang coal mine were divided by geo-dynamic division method, and the stress areas were divided and the stability of roadways was analysis by rock stress state analysis system. The research showed that the in-situ stress field in Hongqingliang coal mine belongs to the horizontal tectonic stress field, which is dominated by horizontal compressive stress. The …

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High Rank Coal Structure And Log Interpretation Method Of Fracture Pressure In Shouyang Block, Li Songlin, Li Zhongcheng, Wang Lina, Duan Jing, Xiang Nian Dec 2020

High Rank Coal Structure And Log Interpretation Method Of Fracture Pressure In Shouyang Block, Li Songlin, Li Zhongcheng, Wang Lina, Duan Jing, Xiang Nian

Coal Geology & Exploration

In order to accurately describe the distribution of surface subsidence basin, and based on the power exponential function model and the subsidence features, the surface subsidence basin model of long-wall working face along strike with gently inclined coal seam was established concerned the combination of theoretical analysis and numerical simulation method. The influencing factors of model parameters and the changing patterns of parameters were analyzed, and the applicability and the predicting accuracy of the model were verified. The results showed that parameter n reflected the range of the bottom size of the sinking basin, which was mainly related to the …

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Mechanism Of Aggregate Start-Up Process And Coupling Of Two-Phase Flow In Hydrodynamic Roadway, Mou Lin Dec 2020

Mechanism Of Aggregate Start-Up Process And Coupling Of Two-Phase Flow In Hydrodynamic Roadway, Mou Lin

Coal Geology & Exploration

Adding heat-conducting filler to the cement of the geothermal well could significantly improve the thermal conductivity of the cement stone and enhance the heat extraction effect of the geothermal well. In this study, on the basis of summarizing the heat conduction path theory and concept of high packing density, the effects of different filler types, particle sizes and dosages on the thermal conductivity of cementing cement were investigated through experiments. The test results showed that graphite had the best effect on improving the thermal conductivity of cement stone compared to other types of filler; the larger the graphite particle size, …

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Hydrogeological Characteristics And Danger-Solving Mining Of Jurassic Baotashan Sandstone—A Case Study In New Shanghai No.1 Coal Mine, Lyu Yuguang, Liu Baokai, Zhao Baofeng, Lyu Wenqing, Han Gang, Wang Yongbao Dec 2020

Hydrogeological Characteristics And Danger-Solving Mining Of Jurassic Baotashan Sandstone—A Case Study In New Shanghai No.1 Coal Mine, Lyu Yuguang, Liu Baokai, Zhao Baofeng, Lyu Wenqing, Han Gang, Wang Yongbao

Coal Geology & Exploration

In order to make up for the deficiency of the regional monitoring of the traditional gas drainage monitoring system, this paper proposes to build a borehole gas drainage monitoring system with borehole as the monitoring unit, which can dynamically grasp the drainage effect of each borehole in the process of gas drainage in real time, change the large area regional measurement into the measurement of each borehole in the region, and realize the fine monitoring of gas drainage. According to the requirements of borehole gas drainage monitoring system, combined with the characteristics of gas drainage parameters at the borehole orifice, …

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Pso-Elm Prediction Model For Surface Deformation Of Mine Slope, Ning Yongxiang, Cui Ximin Dec 2020

Pso-Elm Prediction Model For Surface Deformation Of Mine Slope, Ning Yongxiang, Cui Ximin

Coal Geology & Exploration

During the excavation of the roadway, using reflected in-seam waves detection technique to explore the structure of roadway and accurately interpret the wave impedance interface is of signality for mine production. The method of detecting the position of faults by reflected in-seam waves is usually inaccurate, which is mainly caused by the selected deviation of reflected in-seam waves velocity. In order to reduce the selected deviation of reflected in-seam waves velocity, this paper analyzed the features of reflected in-seam waves velocity of fifteen coal seam in thirteen coal mines and the velocity relationships of reflected in-seam waves, direct in-seam waves …

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Spatial Relationship Between Temperature Field, Hydrothermal Alteration And Main Faults In Shiquan County, Ankang, Xu Li, Ma Runyong, Pan Aifang, Zhang Fan Dec 2020

Spatial Relationship Between Temperature Field, Hydrothermal Alteration And Main Faults In Shiquan County, Ankang, Xu Li, Ma Runyong, Pan Aifang, Zhang Fan

Coal Geology & Exploration

Wide-band, high-power and short-residual acoustic wave sources are the key technology for high-resolution detection of large-scale complex structures, in order to solve the contradiction between detection distance and resolution, a new acoustic wave detection instrument is developed by using the acoustic transmitter made of giant magnetostrictive material(GMM) as the source. The focal center frequency is 5 kHz, and the excitation voltage is 300-600 V, it has the characteristics of large radiated sound power, short residual vibration(3.5 cycles) and frequency band width(1-3 kHz), which solves the problem of the high resolution acoustic wave detection. Its greatest advantage is that the acoustic …

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Hair Clip Type Core Lifter For Improving Coring Quality In Complex Formation And Its Ap-Plication, Liao Yuansu, Hu Qifeng, Miao Sai, Chen Haoxi, Zhuo Lianming Dec 2020

Hair Clip Type Core Lifter For Improving Coring Quality In Complex Formation And Its Ap-Plication, Liao Yuansu, Hu Qifeng, Miao Sai, Chen Haoxi, Zhuo Lianming

Coal Geology & Exploration

Based on the urgent need of accurate exploration of geological anomalous bodies such as collapse columns and small faults in underground coal mines for near-horizontal boreholes coring drilling of leakage formation, the double-wall hydraulic reverse circulation continuous coring technology was proposed, its technical principle and characteristics were analyzed, the matching ø89/42 mm double-wall coring drilling pipes and reverse circulation coring bits were developed. Three near-horizontal coring boreholes were drilled, the functional tests were carried out in a surface mine, the maximum core recovery rate of a single borehole was 83.6%, the maximum roundtrip footage was 69 m and the average …

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Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, Shane Ylagan Dec 2020

Corn And Soybean Response To Wastewater-Recycled Phosphorus Fertilizers, Shane Ylagan

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

The ability to recycle phosphorus (P) from wastewaters could provide a sustainable, continuous source of P that might also help protect surface water quality from P enrichment. The mineral struvite (MgNH4PO4·6H2O) is an understudied material that can be created from Pcontaining wastewater and has been shown to have agricultural fertilizer value. The objective of this study was to evaluate the effects of electrochemically precipitated struvite (ECST), chemically precipitated struvite (Crystal Green; CG), diammonium phosphate (DAP), monoammonium phosphate (MAP), rock phosphate (RP), and triple super phosphate (TSP) on corn (Zea mays) and soybean (Glycine max) response in a 79-day greenhouse pot …

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Developing A Tourism Opportunity Index Regarding The Prospective Of Overtourism In Nepal, Susan Phuyal Dec 2020

Developing A Tourism Opportunity Index Regarding The Prospective Of Overtourism In Nepal, Susan Phuyal

Graduate Theses/Dissertations

This research explores Nepal's overtourism scenario based on the capacity of a locality to manage sustainable tourism practices. Environmental degradation, local infrastructure degradation, negative tourist experience and local resident responses regarding visitors are the four main variables used in this study to analyze overtourism. In order to analyze the case study of overtourism, we select the three top touristic cities of Nepal, Kathmandu, Pokhara, and Chitwan based on the number of annual visitors. Nepal's case analysis of overtourism conditions reviews the overall threat of over-tourism and establishes a metric by which tourism can be viewed as potentially detrimental to sustainability. …

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Save Water Drink Wine: Challenges Of Implementing The Ethnography Of The Temecula Valley Wine Industry Into Food-Energy-Water Nexus Decision-Making, Zaida E. Darley Nov 2020

Save Water Drink Wine: Challenges Of Implementing The Ethnography Of The Temecula Valley Wine Industry Into Food-Energy-Water Nexus Decision-Making, Zaida E. Darley

USF Tampa Graduate Theses and Dissertations

This study demonstrates the interrelationships of people, food, energy, and water associated with Temecula Valley’s wine industry and reveals contradictions and biases in how people view these resources, which ultimately shape management and policies. The FEW (Food, Energy, and Water) Nexus is an approach increasingly used by policy- and decision-makers to understand the interrelationship of several resources. However, a FEW Nexus approach often lacks in social aspects that influence environmentally and economically sustainable outcomes, especially in the wine and wine tourism industry. When quantitative and qualitative data are available, the other challenge is which assessment to use. Two assessments often …

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The Multidisciplinary Enrichment Of Undergraduate Environmental Geology Students From International Summer Programs. Case Study: Summer 2019 3mugis, Russia, Ruslana Baker, Malek Shami, Nazrul I. Khandaker, Stanley Schleifer Oct 2020

The Multidisciplinary Enrichment Of Undergraduate Environmental Geology Students From International Summer Programs. Case Study: Summer 2019 3mugis, Russia, Ruslana Baker, Malek Shami, Nazrul I. Khandaker, Stanley Schleifer

Publications and Research

Hosted by the People’s Friendly University of Russia (RUDN), the Modeling, Monitoring, and Managing of Urban Green Infrastructure (3MUGIS) summer program was organized by the collaboration of the New York City Urban Soil Institute (NYC-USI), City University of New York – Brooklyn College, and under the auspices of the International Union of Soil Sciences (IUSS). The program consisted of one-week lecture sessions and two-weeks of fieldwork across five bioclimatic zones, ranging from the sub-arctic tundra of the Kola Peninsula to the Southern Steps of Rostov, Black Sea. Faculty and guest lecturers included scientists with various expertise from Germany, USA, Russia, …

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Integrating Digital Tools In Remote Learning To Enhance The Delivery Methods Of Technical Content In Undergraduate Geosciences, Ruslana Baker, Malek Shami, Nazrul I. Khandaker, Stanley Schleifer Oct 2020

Integrating Digital Tools In Remote Learning To Enhance The Delivery Methods Of Technical Content In Undergraduate Geosciences, Ruslana Baker, Malek Shami, Nazrul I. Khandaker, Stanley Schleifer

Publications and Research

The global transition to remote learning due to the COVID-19 pandemic was an extremely difficult task for both students and faculty in geological sciences. Technical courses, such as Structural Geology, Mineralogy, Petrology, and Invertebrate Paleontology, that require in-person lectures and laboratory sessions involving various rocks and mineral samples, fossils, maps, and models, were a major concern at the start. The challenge of delivering the technical content via Microsoft Teams, Skype, Webex, Blackboard Collaborate Ultra, Zoom, and other internet based platforms was not only a burden for the faculty to carry, as students were struggling to conceptualize outcrop-and-type-section-based information and link …

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Table Of Contents, The Editors Oct 2020

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

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Evaluation And Analysis Of Paleoenvironments Of The Neogene Oil Shale Of Zhangcun Formation, Qinshui Basin, Liu Yanhai, Li Kunjie, Liu Dongna, Xue Shubin, Liu Yangfe, Chu Yonghui Oct 2020

Evaluation And Analysis Of Paleoenvironments Of The Neogene Oil Shale Of Zhangcun Formation, Qinshui Basin, Liu Yanhai, Li Kunjie, Liu Dongna, Xue Shubin, Liu Yangfe, Chu Yonghui

Coal Geology & Exploration

In order to deeply analyze the indication of oil shale development characteristics on paleoenvironments and provide theoretical guidance for oil shale resource evaluation, the organic geochemistry and elemental geochemistry characteristics of the Neogene Zhangcun Formation oil shale in the central part of the Qinshui basin were analyzed by Rock-Eval and TOC and the paleoclimate and paleogeographic environments of the depositional period were discussed as well. The results show that the oil shale of Zhangcun Formation has the low oil content which Tar=4.15%, higher hydrocarbon potential, kerogen is of sapropel type(I1), which has relatively shallow burial depth. The element …

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Pyrolysis Characteristics And Pyrolysis Product Composition Of Bituminous Coal Under Weak Oxidizing Atmosphere, Zang Libin, Cui Hufeng, Li Qingchun Oct 2020

Pyrolysis Characteristics And Pyrolysis Product Composition Of Bituminous Coal Under Weak Oxidizing Atmosphere, Zang Libin, Cui Hufeng, Li Qingchun

Coal Geology & Exploration

In order to improve the light tar and gas yield, the yield distribution and composition characteristics of pyrolysis products of bituminous coal from Shaanxi Hongliulin in the nitrogen atmosphere and weak oxygen atmosphere were studied in a fixed bed reactor. The results showed that the yield of char and tar were reduced under the weak oxygen atmosphere, and the yield of CO and CO2 increased significantly, leading to the increase of total gas yield. Due to the oxidation combustion reaction, the yield of H2, CH4 and C2-C3 gradually decreased with the increase of …

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Aggregation And Sedimentation Experiments Of Coal Fines With Different Particle Sizes During Cbm Development, Wei Yingchun, Cui Maolin, Zhang Jin, Meng Tao, Yao Zheng Oct 2020

Aggregation And Sedimentation Experiments Of Coal Fines With Different Particle Sizes During Cbm Development, Wei Yingchun, Cui Maolin, Zhang Jin, Meng Tao, Yao Zheng

Coal Geology & Exploration

During the development process of coalbed methane, the aggregation and sedimentation of coal fines can block the migration channel of coalbed methane and lead to accidents such as stuck pump and buried pump. In order to find out the aggregation and sedimentation characteristics of coal fines with different particle sizes, the aggregation and sedimentation experiments of coal fines with the particle size>140 mesh(<106 μm), 70 to 140 mesh(106-212 μm) and 50 to 70 mesh(212-300 μm) in deionized water were carried out. The aggregation and sedimentation characteristics of coal fines with different particle sizes in deionized water suspension were investigated from the suspension observation, the concentration characteristics of coal fines and the particle size distribution of coal fines in suspension. The results show that with the increase of the time, the color of coal fines suspension becomes lighter to different degrees, and the stratification of coal fines suspension gradually appears, and the suspension of coal fines with the particle size more than 140 mesh was the first to stratify among three suspensions. The smaller the particle sizes of coal fines, the more coal fines float on the top of the suspension, and the larger the particle sizes of coal fines, the more coal fines sink to the bottom of the suspension. The concentration of coal fines in the suspensions decreased to different degrees with the increase of the time. The concentration of coal fines decreased the fastest within 3 minutes after stopping the stirring. The concentration of coal fines with the particle sizes of 70 to 140 mesh in suspension was the largest among three suspensions. According to the particle size distribution curves, the process of aggregation and sedimentation of coal fines was divided into three stages: single peak to double peak(rapid floating and settlement of coal fines), double peak to single peak(rapid accumulation and settlement of coal fines) and single peak(slow sedimentation of coal fines). Coal fines with particle size more than 140 mesh in the suspension was the first to reach the stage of slow sedimentation, and coal fines with particle size of 70-140 mesh in the suspension reached the stage of slow sedimentation at the latest among three suspensions. The mechanism of aggregation and sedimentation of coal fines was discussed from the aspects of the force of coal fines, the extended DLVO theory, and the organic molecular structure of coal fines. The coal samples contain a large number of hydrophobic groups, such as aliphatic hydrocarbon and aromatic hydrocarbon, therefore, they have strong hydrophobicity and low wettability. With the decrease of particle sizes of coal fines, its specific surface area increases significantly, and a large amount of air is absorbed on the surface of coal fines, forming an air film. At the same time, particles of coal fines are adsorbed and aggregated with each other, and many micro pores are formed inside, resulting in that coal fines with small particle size is easy to aggregate and float on the suspension surface.

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Progressive Gas Extraction Technology In Broken Soft Coal Seam Of Qinglong Coal Mine, Guizhou Province, Liang Daofu, Cao Jianming, Dai Mao, Chu Zhiwei, Zhang Lei Oct 2020

Progressive Gas Extraction Technology In Broken Soft Coal Seam Of Qinglong Coal Mine, Guizhou Province, Liang Daofu, Cao Jianming, Dai Mao, Chu Zhiwei, Zhang Lei

Coal Geology & Exploration

Aiming at the problems of uncontrollable trajectory, shallow borehole depth and poor gas extraction effect in gas treatment drilling of broken soft coal seam in Qinglong coal mine, the regional progressive gas extraction technology in broken soft coal seam based on compressed-air directional drilling was proposed, on the basis of analyzing the technical bottleneck of existing gas extraction borehole with rotary drilling. The principle and advantage of the technology was expounded, the technology of directional drilling by compressed-air, the technology of long distance in-seam drilling, and the technology of compound slag discharge by double power were integrated. The field test …

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Discussion On The Three-Dimensional Development Model Of The Old Well Pattern In Coalbed Methane Field, Li Jun, Zhang Cong, Zhang Jianguo, Peng He, Cui Xinrui, Zhu Min Oct 2020

Discussion On The Three-Dimensional Development Model Of The Old Well Pattern In Coalbed Methane Field, Li Jun, Zhang Cong, Zhang Jianguo, Peng He, Cui Xinrui, Zhu Min

Coal Geology & Exploration

In order to increase the degree of production of CBM development blocks, when the production of a single well enters a decline period, the development plan needs to be adjusted, and the production increase and stability can be achieved through the measures such as layer adjustment or layer compensation. In terms of time, it is believed that the main coal seam should be developed first when it is put into production. After the decline period, the secondary main coal seam should be supplemented and combined; in space, combined with the development dynamics, the analytic hierarchy process is used to determine …

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Development Characteristics Of Water-Conducting Fractured Zone In Deep Coal Seam Based On Microseismic Monitoring, Hou Enke, Fan Jichao, Xie Xiaoshen, Long Tianwen, Zhang Huanlan, Wang Jianhui, Fan Zhigang Oct 2020

Development Characteristics Of Water-Conducting Fractured Zone In Deep Coal Seam Based On Microseismic Monitoring, Hou Enke, Fan Jichao, Xie Xiaoshen, Long Tianwen, Zhang Huanlan, Wang Jianhui, Fan Zhigang

Coal Geology & Exploration

The development height of the water conducting fractured zone is one of the important technical parameters for mine water hazards prediction. In this paper, the combined well-surface microseismic monitoring technology was used to analyze the development characteristics of the water conducting fractured zone in working face 4103 in Wenjiapo coal mine. The results showed that for deep buried coal seams, the microseismic events occured in the advance mining face with advanced influence angle ranging from the minimum of 28° to the maximum of 35°. The stability of overburden decreased due to the faults. Thus, compared with normal bedrock, the overburden …

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Microseismic Vector Scanning-Based Natural Fracture Monitoring Of The Coalbed Methane Wells, Liu Zixiong Oct 2020

Microseismic Vector Scanning-Based Natural Fracture Monitoring Of The Coalbed Methane Wells, Liu Zixiong

Coal Geology & Exploration

The development degree of natural fractures is the main factor affecting coalbed methane productivity. In order to accurately obtain the distribution position of the natural fractures in the a coalbed methane field in the southern Qinshui basin, 7 refracturing wells in the area were adopted by surface microseismic vector scanning to monitor the natural fractures. A certain amount of three-component geophones were deployed around the fracturing well to collect microseismic events in the surrounding reservoir during fracturing, and after Semblance superposition, the fracture energy slices at different times in the monitoring area were obtained to explain the natural fractures in …

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