A large number of field experiments have shown that the method of gas drainage can effectively solve the problem of gas overrun in coal mining face [4] [5] [6] In fact the study of gas drainage is based on the distance between intubation and drainage negative pressure [7] [8] [9] [10] The coal mining intensity increases year by year with the update and iteration of coal
According to the International Energy Agency IEA 1 global coal power generation accounts for % of total power generation in coal is still an important energy source To date most
The evolution of water flow channels typically includes a micro fracture precursor especially during deep mining However this precursor has not been well characterized To get more insight into this precursor and its development the no 22517 panel in the Dongjiahe coal mine was studied using microseismic monitoring The energy density of microseismic events
Soil sampling and analysis Two large dumps were selected for the present study area of reclaimed land sites RLs and undisturbed native lands between the two dumps were selected as natural land sites NLs Fig 1 The waste dumps were covered with approximately m deep native loess soil and large scale artificial vegetation was
Given the extent of coal mining globally and its potential for a large burden of disease the coal dust generated in mining processes is a serious threat to coal miners safety and health The majority of gas is stored as sorbed gas in water saturated CBM formations which leads to complex dual phase flow during reservoir depletion A
Coal mining Underground mining In underground coal mining the working environment is completely enclosed by the geologic medium which consists of the coal seam and the overlying and underlying strata Access to the coal seam is gained by suitable openings from the surface and a network of roadways driven in the seam then facilitates the installation of
Ineffective environmental regulation of effluent discharged from an underground coal mine operation has enabled water pollution within two highly valued Australian rivers This study investigated the impacts on water chemistry of the Bargo and Nepean rivers as a result of the continuous disposal of mine effluent from Tahmoor Colliery over a 14 month period Coal
Figure 4 illustrates a typical flow sheet of a surface coal mine for the passage of coal from the ground to the point of delivery in the plant Although this may vary from mine to mine the same
Proper understanding of mining induced change in permeability in overburden strata during advancement of longwall faces is essential to estimate the groundwater flow on the overburden strata in order to assist with the assessment of water inrush potential and impact of mining on ground and surface water system In this study numerical modelling approach has
Previous experiences in these mines indicated that the safe pressure head of the groundwater flow in the mined coal layer was approximately 100 to 130 m Transporting water for domestic use from drainage sites to the coal mining district costs Yuan/m 3; and for agricultural purposes transportation costs are Yuan/m 3
1 Introduction The permeability of coal seam is low in most areas in China and coalbed methane exploration on the ground and through underground mine gas extraction becomes difficult [1] [2] China is one of the biggest coal producing countries in the world but the efficiency of its coal gas extraction process is low causing much higher gas emissions than in
A positive correlation r 2 = exists between net alkalinity of the mine water impacted discharges and residence time in the mine pools Our results for the Irwin coal basin suggest that use of a subbasin approach incorporating overburden depth mining methodology and the extent of postmining inundation will lead to improved determination
In addition to the well documented effects of aquatic pollution mining operations can have major impacts on hydrological pathways and flow regime in downstream catchments This paper documents long term 1923 2008 changes in surface drainage areas and runoff characteristics in two small to medium 100 1 000 km2 rivers draining part of the Ordovician
3 Currently royalties from mining exports are absorbed by the Crown into the wider budget pool An amount is then allocated each year to treating acid mine drainage at the Stockton site which produces 80 percent of New Zealand s coal exports The Crown became liable for treatment at the site when state owned Solid Energy folded in 2015
In the process of coal resource mining and consumption utilization a large amount of coal gangue solid waste is accompanied 1 present the western mining area has become the main production
In surface mining the ground covering the coal seam the overburden is first removed to expose the coal seam for extraction The elements of a surface mining operation are 1 topsoil removal and storage for later use 2 drilling and blasting the strata overlying the coal seam 3 loading and transporting this fragmented overburden material called spoil 4 drilling and blasting the
Currently coal mining simulation research is confronted with two significant challenges pertaining to mechanics and flow field modeling Firstly the intense and sustained disturbance of coal mining activities on the overlying strata leads to pronounced changes in the mechanical properties and permeability of the rock strata [19] These
A recent meta analysis of studies of ecological impacts of surface coal mining in the United States found substantial average reductions in taxonomic richness and biotic abundance in streams affected by coal mining Giam et al 2018 and that these biodiversity impacts persist even after site remediation
The foundation of these ideas is the distribution behavior of joints fractures and bed separations and the seep age flow of methane and water through broken rock strata caused by mining [11] Green mining techniques under development include water preserved mining coal mining under infrastructures grouting into the space between separated
Shallow coal seam exploitation not only causes serious surface subsidence but also induces extensive ground fissures which severely threaten the safety of underground mining and the surface eco environment We use the Daliuta coal mine of the Shendong mining district in China as a case study to investigate and characterize the influence of underground coal mining
Surface mining activities are the dominant form of land use in some regions and penetrate far more deeply below the earth surface than other forms of land use change Mountaintop mining a form of surface mining used in steep landscapes is now the dominant form of coal extraction and land cover change in the Central Appalachian ecoregion of the United States an area that
