scholarly journals Using the Magnetotelluric Method for Detecting Aquifer Failure Characteristics under High-Intensity Mining of Thick Coal Seams

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4397 ◽  
Author(s):  
Erhu Bai ◽  
Wenbing Guo ◽  
Dongsheng Zhang ◽  
Yi Tan ◽  
Mingjie Guo ◽  
...  
Keyword(s):  
High Intensity ◽  
Physical Simulation ◽  
Northwest China ◽  
Mining Area ◽  
Coal Seams ◽  
Basic Principles ◽  
Failure Characteristics ◽  
Fast Detection ◽  
Downward Seepage ◽  
Magnetotelluric Method

In the ecologically fragile mining area of northwest China, high-intensity mining has seriously affected the aquifer and surface eco-environment. In order to better implement water-preserved mining in ecologically fragile areas, the aquifer failure characteristics should be first detected accurately; therefore, it is necessary to find a convenient and fast detection method. Based on the analysis of the basic principles and influencing factors of the magnetotelluric (MT) method, the feasibility of using the MT method to detect aquifer failure is verified by testing the mined area with MT detection and field borehole measurement. Subsequently, the failure characteristics of overburden and unconsolidated aquifers under high-intensity mining are studied by MT detection and physical simulation. By comparing the physical simulation with the field measurement from the aspects of the maximum surface subsidence, interval of periodic weighting and step cracks, the reliability of the height of the water flowing fracture zone and caving zone obtained from physical simulation is verified. The analysis from MT detection and physical simulation shows that the results of the two methods are in accord with each other, which further confirms that the MT method can be used to detect the failure of overburdened structures and aquifers. The penetrating fractures are the main channel for the downward seepage of water resources, which is caused by the “two-zone” of overburden model and located in the “dimple” shape in the apparent resistivity (AR) isogram. It can provide a reference and technical support for the corresponding new water-preserved mining technology and the construction of digital mines.

scholarly journals A novel environmental restoration method for an abandoned limestone quarry with a deep open pit and steep palisades: a case study

2018 ◽  
Vol 5 (5) ◽  
pp. 180365 ◽  
Author(s):  
Hanxun Wang ◽  
Bin Zhang ◽  
Xueliang Bai ◽  
Lei Shi
Keyword(s):  
Construction Materials ◽  
Environmental Issues ◽  
Northwest China ◽  
Mining Area ◽  
Shaanxi Province ◽  
Open Pit ◽  
Environmental Restoration ◽  
Land Occupation ◽  
Limestone Quarry ◽  
Restoration Work

In general, exploitation of rock materials, such as limestone or granite exploitation, can cause serious damage to the environment near a mine area. With economic development and the ever-increasing demand for ore resources, mining activities have induced very serious environmental issues in China. Therefore, environmental restoration work around mines in China is urgently required. This study explores the Chuankou open-pit limestone quarry in Tongchuan City, Shaanxi Province, Northwest China, as the engineering case. The environmental issues caused by over 40 years of limestone exploitation, including land degradation, land occupation, dust pollution and potential geological disasters, were investigated. Combining the characteristics of this quarry with a summary of previous studies on environmental restoration work, this paper proposes a novel and systematic method that was comprehensively carried out through engineering and revegetation measures. The engineering measure, that is, the construction of an artificial slope by using local abandoned construction materials, solved the environmental problems in this quarry and provided site conditions favourable for revegetation. The revegetation measure restored the local ecosystem. This method provides both a new idea for the sustainable development of a mining area and a useful reference for analogous engineering cases.

Instrument for Studying Wake Fields Influence to International Linear Collider High Intensity Bunch

2009 ◽  
Vol 4 (1) ◽  
pp. 30-36
Author(s):  
Petr Bak ◽  
Dmitriy Bolkhovityanov ◽  
Andrey Korepanov ◽  
Pavel Logatchev ◽  
Dmitriy Malyutin ◽  
...  
Keyword(s):  
Electron Beam ◽  
Measurement Error ◽  
High Intensity ◽  
Linear Collider ◽  
International Linear Collider ◽  
Basic Principles ◽  
Beam Interaction ◽  
Simulation Results ◽  
Main Components ◽  
Wake Fields

Instrument for bunch tilt measurements in linear collider is presented. Electron beam probe basic principles are described and method of bunch tilt measurements is discussed. The simulation results of testing beam interaction with tilted relativistic bunch are presented. Main components of the bunch tilt measurement error are determined.

scholarly journals A new fast detection system at the KWS-2 high-intensity SANS diffractometer of the JCNS at MLZ - prototype test

2016 ◽  
Vol 746 ◽  
pp. 012026 ◽  
Author(s):  
A Radulescu ◽  
N Arend ◽  
M Drochner ◽  
A Ioffe ◽  
G Kemmerling ◽  
...  
Keyword(s):  
High Intensity ◽  
Detection System ◽  
Fast Detection ◽  
Prototype Test

scholarly journals Mineralogical characteristics and sources of alkali metals in the No. 6 coal seam from the Fukang mining area of the Zhunnan coalfield, Xinjiang province, Northwest China

2019 ◽  
Vol 37 (3) ◽  
pp. 1162-1181 ◽  
Author(s):  
Yun Xu ◽  
Handong Liang ◽  
Ning Zhang
Keyword(s):  
Coal Seam ◽  
Inductively Coupled Plasma ◽  
Alkali Metals ◽  
Northwest China ◽  
Mining Area ◽  
Major Elements ◽  
Middle Part ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

Minerals in coal are of great significance in determining coal properties, washing, combustion, gasification, and liquefaction. The content of alkali metals in coal is an important factor determining corrosion and/or erosion in combustion boilers. Eleven coal samples were taken from the No. 6 coal seam of the Fukang mining area, Zhunnan coalfield, Xinjiang province, China. X-ray fluorescence, inductively coupled plasma-mass spectrometry, low-temperature ashing-X-ray diffraction, and electron probe microanalyzer were used for analyzing the minerals, major elements, and trace elements of the coal. The results indicated that the minerals mainly consist of dawsonite, dolomite, albite, calcite, kaolinite, quartz. The average content of Na2O in the ash of the No. 6 coal seam samples was 10.91%. Na mainly occurs in the form of organic compounds in the No. 6 coal seam, then in the form of inorganic minerals, such as dawsonite and albite. Na in surface and underlying strata was brought into the coal by water and combined with organic matter, resulting in relatively high Na contents in the upper and bottom parts of the coal seam and relatively low Na contents in the middle part.

Study on the Regularity of Surface Movement and Deformation in Long Coal Face with Large Mining Height

2012 ◽  
Vol 594-597 ◽  
pp. 86-91
Author(s):  
Zu Qiang Xiong ◽  
Jun He ◽  
Lei Lei Zhao
Keyword(s):  
Horizontal Displacement ◽  
Mining Area ◽  
Coal Seams ◽  
Coal Face ◽  
Abscission Layer ◽  
Surface Movement ◽  
Face Length ◽  
Large Mining Height ◽  
Movement And Deformation ◽  
Space Range

It is an important way to realize mine intensive production by increasing of the coal face length. During the transformation period of mining methods about thick coal seams, the character parameters of surface movement and deformation will be provided to guarantee scientifically mining of thick coal seams in Jincheng mining area. In this paper, numerical simulation, theoretical analysis and field measurement are used for studying the influence of coal face length on surface movement and deformation in the condition of large height mining. The results show that the separated strata space range extended with the increasing of coal face length and advancing distance, the surface movement and deformation become more violent, the mining influenced range also gradually expands, and the maximum surface subsidence and horizontal displacement increases gradually in form of linear relationship. In the condition of fast mining, the duration of abscission layer reduces, and the surface movement and deformation shows obviously hysteretic and zonal characteristic.

scholarly journals Analysis of methane hazard in longwall working equipped with a powered longwall complex

2020 ◽  
Vol 174 ◽  
pp. 01011
Author(s):  
Leszek Sobik ◽  
Jarosław Brodny ◽  
Gennady Buyаlich ◽  
Pavel Strelnikov
Keyword(s):  
High Performance ◽  
Underground Mining ◽  
Practical Knowledge ◽  
Mining Operation ◽  
Mining Area ◽  
Hard Coal ◽  
Coal Seams ◽  
Methane Drainage ◽  
High Degree ◽  
Advanced Model

Most of currently exploited hard coal seams has a very high degree of methane saturation. Consequently, the mining process of such deposits generates substantial amounts of methane. This in turn increases the risk of fire and/or explosion of this gas. Methane hazard is currently one of the most dangerous threats occurring in the process of underground mining exploitation. In particular, this applies to longwall excavations where the rock mass mining process generates the highest level of this gas. Commonly used high-performance longwall complexes cause an increase in the amount of coal output, which also causes an increase in the amount of methane released. In order to prevent hazardous concentrations, appropriate ventilation systems and atmosphere monitoring in mining excavations are used. The paper discusses currently used methods designed to limit risks caused by methane such as methane drainage. The paper presents an example of the use of an innovative method of analysing methane risk status and measures aimed at minimizing it. The developed method is based on air parameters in the actual mining area which were then used to create a method of ventilation for such excavations. The method combines advanced model analysis and experience of mine employees and integrates academic and practical knowledge. The main objective of the activities presented in the article was to improve the safety of mining operation

Geochemical Characteristics and Comprehensive Utilization of the Main Coal Seams in Wubu Mining Area, Northern Shaanxi Province

2013 ◽  
Vol 734-737 ◽  
pp. 755-758
Author(s):  
Zhi Xue Li ◽  
Ming Pei Li ◽  
Long Yi Shao
Keyword(s):  
Elemental Analysis ◽  
Chemical Properties ◽  
Calorific Value ◽  
Mining Area ◽  
Proximate Analysis ◽  
Shaanxi Province ◽  
Coal Seams ◽  
Comprehensive Utilization ◽  
Coal Analysis ◽  
Northern Shaanxi

Use a variety of coal analysis methods on the Wubu mining area main coal seams S1 and T1 in proximate analysis, elemental analysis, and technologic property analysis, the results show that the main coal seams is a kind of medium ash, medium volatile coal, especially low-medium sulfur, high calorific value coal. They have a good chemical properties and technologic properties, and can be used for coking, civilian, steam coal.

scholarly journals Study on evolution characteristics of overburden caving and void during multi-horizontal sectional mining in steeply inclined coal seams

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 3915-3921
Author(s):  
Wen-Hua Yang ◽  
Xing-Ping Lai ◽  
Jian-Tao Cao ◽  
Hui-Cong Xu ◽  
Xian-Wei Fang
Keyword(s):  
Fractal Dimension ◽  
Simulation Model ◽  
Coal Mine ◽  
Void Ratio ◽  
Physical Simulation ◽  
Thermal Image ◽  
Mine Pressure ◽  
Coal Seams ◽  
Temperature Changes ◽  
Evolution Characteristics

In this paper, the evolution characteristics of overburden caving and void during multi-horizontal sectional mining in steeply inclined coal seams are studied. Based on the typical engineering background of steeply inclined coal seams mining in Wudong Coal Mine, the physical simulation model is build. The evolution characteristics of overburden caving and void during multi-horizontal sectional mining is systematically studied, combined with the monitoring data of overburden infrared thermal image, void ratio, void network fractal dimension, and peak mine pressure. It is showed that, during multi-horizontal sectional mining in steeply inclined coal seams, the movement rule of overburden is extremely complicated, and the temperature changes in infrared thermal image were significant.

scholarly journals Statistical analysis of distribution patterns of coal seams in fold zones in Northwest China

2018 ◽  
Vol 28 (5) ◽  
pp. 819-828 ◽  
Author(s):  
Anye Cao ◽  
Guangcheng Jing ◽  
Linming Dou ◽  
Yun Wu ◽  
Chengguo Zhang
Keyword(s):  
Statistical Analysis ◽  
Distribution Patterns ◽  
Northwest China ◽  
Coal Seams

scholarly journals Petrography, Mineralogy, and Geochemistry of Combustion Metamorphic Rocks in the Northeastern Ordos Basin, China: Implications for the Origin of “White Sandstone”

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1086
Author(s):  
Bin Chen ◽  
Yanyan Wang ◽  
Marco Franceschi ◽  
Xiong Duan ◽  
Kuizhou Li ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Ordos Basin ◽  
Northwest China ◽  
Metamorphic Rocks ◽  
Coal Seams ◽  
Quaternary Period ◽  
X Ray ◽  
Coal Fire ◽  
Icp Ms ◽  
Coal Fires

Since the Quaternary period, tectonic uplift and river erosion in the northeastern Ordos Basin (northwest China) have exhumed numerous coal seams, creating the conditions for the development of coal fires following their spontaneous combustion or other types of ignition (e.g., lightning strikes). Coal fires activity is testified by the widespread occurrence of combustion metamorphic rocks. In this study, thin section analyses, scanning electron microscopy, X-ray diffraction (XRD), X-ray fluorescence (XRF), and inductively coupled plasma mass spectrometry (ICP-MS) were used to investigate in detail the mineralogical and geochemical characteristics of combustion metamorphic rocks in the Jurassic succession of the northeastern Ordos Basin. The samples collected in localities distributed over an area of about 8000 km2 were analyzed to determine their mineral association, revealing the presence of tridymite, cristobalite, mullite, and cordierite that are typically produced in pyrometamorphic reactions. XRF and ICP-MS analyses revealed that combustion metamorphic rocks are iron-enriched. Investigations in the study area also highlighted the occurrence of a peculiar, porous, and permeable white sandstone that appears often associated with clinkers or coal seams. It is composed of quartz and feldspar grains and cemented by kaolinite. It is here suggested that the white color of this sandstone could be due to coal fire-related kaolinization of a sandstone protolith produced by the acidic low-temperature hydrothermal circulation of rain waters during times of coal fire activity.

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