Element geochemical characteristics and formation environment for the roof, floor and gangue of coal seams in the Gujiao mining area, Xishan coalfield, China

2018 ◽  
Vol 190 ◽  
pp. 336-344 ◽  
Author(s):  
Gang Wang ◽  
Yiwei Xie ◽  
Yong Qin ◽  
Jinxi Wang ◽  
Jian Shen ◽  
...  
Keyword(s):  
Mining Area ◽  
Geochemical Characteristics ◽  
Coal Seams

scholarly journals Geochemical Characteristics and Prospecting Prediction of Sediment in Songwang Area, Bobai County, Guangxi

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Wai Yi
Keyword(s):  
Water System ◽  
Mining Area ◽  
Geochemical Characteristics ◽  
Good Prospect ◽  
Mining Areas ◽  
Geological Characteristics ◽  
Geochemical Anomalies ◽  
Magmatic Rocks ◽  
Prospecting Prediction

The characteristics of strata, structures, magmatic rocks, lithology and mineralization in Dongtao mining area (Songwang area) of Bobai County, Guangxi were summarized. According to the geochemical anomalies of sediment in water system, and the main anomalies are explained and evaluated, combined with the geological characteristics of Dongtao and other mining areas, the prospecting prediction of favorable areas is carried out, and it is considered that there is a good prospect of prospecting.

The differences of element geochemical characteristics of the main coal seams in the Ningdong coalfield, Ordos Basin

2019 ◽  
Vol 202 ◽  
pp. 77-91 ◽  
Author(s):  
Liu Zhifei ◽  
Wei Yingchun ◽  
Ning Shuzheng ◽  
Jia Xu ◽  
Qin Rongfang ◽  
...  
Keyword(s):  
Ordos Basin ◽  
Geochemical Characteristics ◽  
Coal Seams

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 Geochemical characteristics of elements in coal seams 41 and 42 of Heshan Coalfield, South China

2019 ◽  
Vol 38 (1) ◽  
pp. 137-157 ◽  
Author(s):  
Qiaojing Zhao ◽  
Yongjie Niu ◽  
Zhizhong Xie ◽  
Kuangming Zhang ◽  
Jinming Zhou ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Geochemical Characteristics ◽  
X Ray Diffraction ◽  
Coal Seams ◽  
X Ray ◽  
Inductively Coupled ◽  
Reducing Environment ◽  
Conventional Microscopy ◽  
Hydrothermal Activities ◽  
Scanning Electron

Coal seams 41 and 42 of the Heshan Coalfield belong to superhigh-organic-sulfur coals. In order to study the geochemical characteristics of the coals, 15 coal samples and 6 rock samples were collected from both coal seams and the roof/floor rocks. The samples were investigated by using conventional microscopy, inductively coupled plasma mass spectroscopy, X-ray diffraction, X-ray fluorescence, and scanning electron microscopy with an energy-dispersive X-ray spectroscopy. The results show that minerals in the coals are dominated by kaolinite and a mixed layer illite/smectite and illite; small ratios of pyrite, quartz, chlorite, smectite, calcite, and dolomite are also present. Under the microscope, these pyrites occur as framboidal, euhedral, homogeneous, anhedral, nodular, and fine dissemination shapes. In Shicun Mine, the trace elements Li, Y, Zr, Sn, Sm, and Tb are enriched; Zn and Ba are depleted. However, in the Heliluoshan Mine, Mo is significantly enriched; Li, Zr, Cs, and U are enriched; and Co and Ba are depleted. The occurrence of Li and Ga is associated mainly with organic matter and sulfate minerals. U and Mo occur in silicate minerals, carbonate minerals, illite, I/S, and pyrite. A reducing environment is beneficial for the enrichment of V, Cr, Mn, Ni, Mo, Cd, and U. The abundances of sulfur in Heshan were controlled mainly by the degree of seawater influence and hydrothermal activities.

Research on the Characteristics of Gas Geology in Yongshanqiao Mining Area, Jiangxi Province

2012 ◽  
Vol 164 ◽  
pp. 511-516
Author(s):  
Zhi Gen Zhao ◽  
Ming Ming Zhang ◽  
Jia Ping Yan
Keyword(s):  
Emission Rate ◽  
Mining Area ◽  
Geological Structure ◽  
Controlling Factors ◽  
Jiangxi Province ◽  
Coal Seams ◽  
Gas Emission ◽  
Gas Generation ◽  
Coal Quality ◽  
Geological Factors

The coal and gas outburst is very serious in Yongshanqiao Mining Area of Jiangxi province, so it is of significance to research the characteristics of gas geology and their controlling factors. Based on the statistical analysis of gas data during coal exploration and coal mining, the regularity is revealed of the characteristics of gas geology in Yongshanqiao Mining Area. From east to west and from south to north, the relative gas emission rate and the absolute gas emission rate tend to increase, the frequency and intensity of coal and gas outbursts rise, the gas contents also tend to increase. The controlling factors of characteristics of gas geology in Yongshanqiao Mining Area are researched in this paper. The work reveals that: corresponding to characteristics of gas geology, the distribution characteristics of coal quality, the characteristics of geological structure and the lithology characteristics of the roof and the floor of the coal seams in Yongshanqiao Mining Area present regular changes, and are all favorable to gas generation and gas preservation. So, the characteristics of gas geology in Yongshanqiao Mining Area are the result of comprehensive effects by geological factors

SUBSTANTIATION OF PARAMETERS OF THE EXPERIMENT WITH THREE-DIMENSIONAL COMPUTER MODELING OF THE ROCK MASS AROUND A LONGWALL

2021 ◽  
pp. 37-48
Author(s):  
Sergey Vlasov ◽  
◽  
Yavhen Moldavanov ◽  
Keyword(s):  
Rock Mass ◽  
Computer Modeling ◽  
Coal Mining ◽  
Three Dimensional ◽  
Mining Area ◽  
Practical Significance ◽  
Coal Seams ◽  
Working Face ◽  
Powered Support ◽  
The Difference

Purpose. To substantiate the parameters of computer modeling of the mining area with a step-by-step movement of the working face, as well as taking into account the changing presence of sandstones that lie in the top of the reservoir, to predict the effect of sandstones on the nature of the distribution of convergence in the longwall and the technology of working excavation in the conditions of the mines of Western Donbass. Methods. The work uses a statistical analysis of the geological and technological conditions that are inherent in the coal mining enterprises of the Western Donbass. Also, a comparison was made of the parameters of the experiment of computer modeling of past studies, on the basis of which, a combination of new features was introduced and changed, which is aimed at choosing the optimal modeling parameters. Results. The substantiation of the parameters of the modeling experiment is presented, such as: the choice of the length of the working face, the depth of development of coal seams, the distance of the working face withdrawal from the assembly chamber, the values of the thickness of sandstones that lie in the roof of the coal seams, the choice of values of the distance of occurrence of sandstones above the roof of the coal seam, as well as geometric parameters of the computer model. Based on the justification of the parameters, a plan for conducting experiments was drawn up, the number of which was 225 units. Scientific novelty. As a result of the substantiation of the parameters, an additional combination of new features in existing studies was proposed for the first time, namely, to include in the experiment the presence of coal seams in the top – sandstones with variable thickness, the distance of occurrence above the seam, several standard sizes of the length of the working face were also included, the value of the development depth, the distance of the exit of the working face from the assembly chamber. Changing the above parameters will make it possible to compare the difference in the effect of the results of each experiment separately, depending on the change in each of the parameters, as well as to understand and generalize the idea of ​​the nature and causes of emergency longwall stops associated with the landing of powered support sections “on a hard base”. Practical significance. Substantiated modeling parameters make it possible to most adequately reflect the processes occurring in the rock mass, as well as to clarify the parameters of the reference rock pressure zones, unloading zones, as well as the nature of the change in the distribution of convergence in the longwall. The data obtained as a result of modeling can be used to select and substantiate an effective method for managing the state of the rock mass around the working excavation, which will eliminate the planting of powered support sections “on a hard base”, thereby increasing the efficiency of coal mining in the Western Donbass.

INFLUENCE OF ANALYSIS RESULTS OF ANALYTICAL COAL SAMPLES ON THE PREDICTION ACCURACY OF HAZARDOUS PROPERTIES OF COAL SEAMS

2021 ◽  
pp. 176-186
Author(s):  
Yevhen Rudniev ◽  
◽  
Vyacheslav Galchenko ◽  
Elvira Filatieva ◽  
Mykhailo Filatiev ◽  
...  
Keyword(s):  
Coal Mine ◽  
Calorific Value ◽  
Mining Area ◽  
The State ◽  
Coal Seams ◽  
Initial State ◽  
Mining Operations ◽  
Mineral Components ◽  
Scientific Substantiation

Purpose: to establish possible quantitative errors in determining the values of some indicators of the degree of metamorphism without attracting the content of total moisture and mineral impurities to predict the hazardous properties of coal mine layers during mining. Methodology: based on the use of initial data on the quality indicators and properties of coals for specific coal seams, given in the reference sources, with the subsequent recalculation of the state of samples from their dry ashless or ashless state to the raw state. Comparison of the samples of indicators were determined, respectively, using analytical samples and based on the results of recalculation to the initial state (close to the production state), conclusions were drawn about possible errors in the case of using the analysis results of the analytical samples to predict hazardous properties of mines. Results: The analytical state of the samples for dry ashless state (daf) or wet ashless state (af) does not correspond to the state of coal in the working area of mining operations (r), which most accurately characterizes the manifestation of mine hazardous properties. The indicators of the release of volatile substances during thermal decomposition of coals, which are used to predict the hazardous properties of mine coal seams, do not directly reflect changes in the elemental composition of coals during metamorphic transformations. Methods for preparing analytical samples provide for grinding to small fractions, removing external moisture and enriching to ash content less than 10%, which does not correspond to the state of coal (r) in the mining area. The use of indicators set for dry ashless combustible (organic) mass excludes the possibility of analyzing the influence of moisture and mineral impurities on the manifestation of the hazardous properties of coal seams. The use of such indicators to predict the hazardous properties of mine coal seams can lead to errors in their determination of 45 ÷ 50%. The hazardous properties of coal seams can be adequately characterized only by the combined composition and properties of organic matter and mineral impurities in a state close to the presence of coal in the mining area. Using the example of possible significant errors in the calorific value, in the case of its use to characterize the hazardous properties of coal mine seams, the expediency of scientific substantiation of a set of indicators for a reliable forecast of a specific hazardous property for a specific seam formation was proved. Scientific novelty: hazardous properties of coal seams are reliably predicted on the basis of the composition and properties of organic and mineral components, reduced to conditions close to the state during mining operations. Practical value: the results obtained give grounds to scientifically substantiate the selection of the necessary indicators for predicting a specific hazardous property of coal seams and make proposals for improving the regulatory framework for the safe conduct of mining operations.

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