恩洪-老厂地区煤层气成藏条件研究     

桂宝林 《云南地质》2004,23(4):421-433

煤层气盆地、煤层气系统、煤层气区带的存在及发育程度是煤层气藏形成的充分与必要条件。恩洪盆地和老厂一圭山盆地老厂煤矿区具备了形成煤层气藏的条件。研究其形成煤层气藏的特定条件，总结其煤层气藏模式，是煤层气勘探目标评价的基础。  相似文献   

疏降地下水引起地面塌陷浅析--以淮南煤矿区为例   总被引：4，自引：0，他引：4  

许光泉  沈慧珍 《中国地质灾害与防治学报》2004,15(4):64-68

以淮南西部矿区为例，介绍了该地区自20世纪60年代开采煤矿以来，由于疏降地下水，引起的地面塌陷。为了研究灰岩水动力场规律，先后在该区进行多时段、多水平放水试验。研究表明，覆盖粘土层、岩溶及人工疏降地下水，是该地区岩溶塌陷形成的基本条件。通过对粘土盖层性质、疏降地下水岩溶塌陷演化过程及塌陷机理与对应阶段过程综合分析，结合区域地质条件，掌握了塌陷点的分布规律。对目前西部地区塌陷“复活”、整治及未来城市规划，提出了建设性建议。  相似文献   

Geological controls on rock mass classification of coal from Huntly East Mine, New Zealand     

Vicki Moon  Trisha Roy 《Engineering Geology》2004,75(2):201-213

Rock Mass Rating (RMR) measurements from 65 sites within Huntly East underground coal mine are presented. All measurements are in coal, for which the dominant discontinuities are vertical cleat. Basic RMR values using two discontinuity spacings are presented: overall RMR based on the average spacing of all individual discontinuities; and cleat zone RMR based on the average spacing between zones of cleat. Cleat orientations are highly variable, but on average approximately parallel horizontal stress axes (face cleat follows maximum horizontal stress axis, butt cleat follows minimum horizontal stress axis).Contours of RMR variations throughout the mine are used to compare rock mass conditions with geological structure. It is apparent that: (1) RMR is least within downthrown fault blocks, and particularly immediately on the downthrown sides of faults, and greatest in upthrown fault blocks; and (2) RMR contours parallel horizontal stress axes within fault-bounded blocks, and bend to parallel faults at block boundaries. From similar contours for parameters contributing to RMR, the Rock Quality Designation (RQD), groundwater rating, and discontinuity condition rating create most of the observed variations in RMR. RQD is determined from the measured discontinuity frequency and hence is a measure of the degree of fracturing of the rock mass. This is interpreted as influencing the groundwater and condition parameters directly by allowing greater water ingress. Discontinuity frequency is greatest (least spacing) in the immediate vicinity of faults, and in downthrown fault blocks, generating low RMR values. Within fault blocks RQD varies little, so RMR contours align with cleat orientations.As RMR contours, faults, stress field and cleat orientation are clearly interrelated, there is unequivocally a connection between RMR and structural geology; this allows some predictive capacity in terms of ground conditions. If geological features can be accurately defined through either drilling programs or seismic surveys, then ground conditions may be predicted before panels are driven.  相似文献   

From in-situ coal to fly ash: a study of coal mines and power plants from Indiana     

Maria Mastalerz  James C Hower  Agnieszka Drobniak  Sarah M Mardon  Grzegorz Lis   《International Journal of Coal Geology》2004,59(3-4):171-192

This paper presents data on the properties of coal and fly ash from two coal mines and two power plants that burn single-source coal from two mines in Indiana. One mine is in the low-sulfur (<1%) Danville Coal Member of the Dugger Formation (Pennsylvanian) and the other mines the high-sulfur (>5%) Springfield Coal Member of the Petersburg Formation (Pennsylvanian). Both seams have comparable ash contents (11%). Coals sampled at the mines (both raw and washed fractions) were analyzed for proximate/ultimate/sulfur forms/heating value, major oxides, trace elements and petrographic composition. The properties of fly ash from these coals reflect the properties of the feed coal, as well as local combustion and post-combustion conditions. Sulfur and spinel content, and As, Pb and Zn concentrations of the fly ash are the parameters that most closely reflect the properties of the source coal.  相似文献   

Modes of occurrence of mercury and other trace elements in coals from the warrior field, Black Warrior Basin, Northwestern Alabama   总被引：1，自引：0，他引：1  

S.F Diehl  M.B Goldhaber  J.R Hatch   《International Journal of Coal Geology》2004,59(3-4):193-208

The mineralogic residence and abundance of trace metals is an important environmental issue. Data from the USGS coal quality database show that potentially toxic elements, including Hg, As, Mo, Se, Cu, and Tl are enriched in a subset of coal samples in the Black Warrior Basin of Alabama, USA. Although the coal as-mined typically is low in these elements, localized enrichments occur in high-pyrite coals and near faults. Microscopic analyses demonstrate that the residence of these elements is dominantly in a late-stage pyrite associated with structurally disrupted coal. Further, our data suggest addition of Hg to the coal matrix as well. The source of these trace elements was hydrothermal fluids driven into the Black Warrior Basin by Alleghanian age tectonism.  相似文献   

Geological investigations at a high altitude, remote coal mine on the Northwest Pakistan and Afghanistan frontier, Karakoram Himalaya     

Laurance J. Donnelly 《International Journal of Coal Geology》2004,60(2-4):117-150

The Northwest Pakistan and Afghanistan frontier is located one of the most remote, inaccessible, and inhospitable part of the Himalayan orogenic belt. In this region, two of the world's largest and most distinct mountain belts intersect; the Karakoram Himalaya (mainly in Pakistan) and the Hindu Kush (mainly in Afghanistan). Located at high altitude, in a remote part of Northwest Pakistan, close to the border with Afghanistan, tribal villagers began excavating a series of adits into the steep mountain slopes, beneath glaciers, to extract valuable coal and carbonaceous shale resources. These were discovered in 1996, by the villagers, whilst hunting, and may represent some of the highest mine workings in the world. Small-scale mining operations subsequently developed using rudimentary mining methods and the mine became known as the Reshit or Pamir Coal Mine.The coal deposits are sedimentary, highly disturbed and tectonised, having been subjected to multiple phases of orogenic crustal deformation. The coal occurs as discrete lenses, several tens of metres in their lateral dimension, between steeply dipping, overturned and thrusted limestone beds of Jurassic age. The coal provided a vital, alternative source of fuel for the villagers since the local, traditional fuel supply was wood, which had become severely depleted, and imports of kerosene from neighbouring China and Afghanistan were too expensive.The mining operations experienced severe problems. These included several collapses of mine entrances, the failure of the adits to intersect the coal-bearing zones, the potential threat of geological hazards, mining-induced hazards and harsh high-altitude operating conditions, particularly during the winter months. International aid was provided to assist the villagers and a geological investigation was commissioned to investigate the problems at the mine.The geology of Karakoram Himalaya is relatively poorly understood. Until recently the region was restricted to foreign visitors and large areas of this mountain belt are virtually unmapped. Existing geological and topographic maps are difficult to obtain or are unavailable due to the close proximity of political frontiers, national borders and security reasons. The mineral resource potential of this region is virtually unknown. Few western geologists have visited this area due to its inaccessibility and political constraints, being situated close the frontiers with China, Afghanistan, and the disputed Pakistan and India territory of Kashmir.The Pakistan and Afghanistan border, is once again, now closed to foreign visitors. The objectives of this paper are to document the occurrence of coal and carbonaceous shale, at high altitude, in the Karakoram Himalaya and to provide details on the geology, geological hazards, reserves and labour-intensive mining operations. These observations and information may provide the basis for future mineral exploration, mining-geology, mining-engineering, feasibility studies and engineering geological investigation in the Karakoram Himalaya.  相似文献   

Mineralogy and geochemistry of a Late Permian coal in the Dafang Coalfield, Guizhou, China: influence from siliceous and iron-rich calcic hydrothermal fluids   总被引：16，自引：2，他引：16  

Shifeng Dai  Chen-Lin Chou  Mei Yue  Kunli Luo  Deyi Ren   《International Journal of Coal Geology》2005,61(3-4):241-258

This paper describes the influence of siliceous and iron-rich calcic low-temperature hydrothermal fluids (LTHF) on the mineralogy and geochemistry of the Late Permian No. 11 Coal (anthracitic, R_r=2.85%) in the Dafang Coalfield in northwestern Guizhou Province, China. The No. 11 Coal has high contents of vein ankerite (10.2 vol.%) and vein quartz (11.4 vol.%), with formation temperatures of 85 and 180 °C, respectively, indicating that vein ankerite and vein quartz were derived from low-temperature calcic and siliceous hydrothermal fluids in two epigenetic episodes. The vein quartz appears to have formed earlier than vein ankerite did, and at least three distinct stages of ankerite formation with different Ca/Sr and Fe/Mn ratios were observed.The two types of mineral veins are sources of different suites of major and trace metals. Scanning electron microscope and sequential extraction studies show that, in addition to Fe, Mg, and Ca, vein ankerite is the dominant source of Mn, Cu, Ni, Pb, and Zn in the coal, and the contents of these five elements are as high as 0.09% and 74.0, 33.6, 185, and 289 μg/g, respectively. In contrast, vein quartz is the main carrier mineral for platinum-group elements (PGEs) Pd, Pt, and Ir in the coal, and the contents of Pd, Pt, and Ir are 1.57, 0.15, and 0.007 μg/g, respectively. Sequential extraction showed a high PGE content in the silicate fraction, up to 10.4 μg/g Pd, 1.23 μg/g Pt, and 0.05 μg/g Ir, respectively. It is concluded that the formation of ankerite and quartz and the anomalous enrichment of trace elements in the No. 11 Coal in the Dafang Coalfield, Guizhou, result from the influx of calcic and siliceous low-temperature hydrothermal fluids.  相似文献   

Mercury in Eastern Kentucky coals: Geologic aspects and possible reduction strategies     

James C. Hower  Cortland F. Eble  Jeffrey C. Quick 《International Journal of Coal Geology》2005,62(4):223-236

Mercury emissions from US coal-fired power plants will be regulated by the US Environmental Protection Agency (USEPA) before the end of the decade. Because of this, the control of Hg in coal is important. Control is fundamentally based on the knowledge of the amounts of Hg in mined, beneficiated, and as-fired coal. Eastern Kentucky coals, on a reserve district level, have Hg contents similar to the USA average for coal at mines. Individual coals show greater variation at the bench scale, with Hg enrichment common in the top bench, often associated with enhanced levels of pyritic sulfur. Some of the variation between parts of eastern Kentucky is also based on the position relative to major faults. The Pine Mountain thrust fault appears to be responsible for elemental enrichment, including Hg, in coals on the footwall side of the thrust.Eastern Kentucky coals shipped to power plants in 1999, the year the USEPA requested coal quality information on coal deliveries, indicate that coals shipped from the region have 0.09 ppm Hg, compared to 0.10 ppm for all delivered coals in the USA. On an equal energy basis, and given equal concentrations of Hg, the high volatile bituminous coals from eastern Kentucky would emit less Hg than lower rank coals from other USA regions.  相似文献   

Optical properties of pseudovitrinite; implications for its origin     

Maria Mastalerz  Agnieszka Drobniak 《International Journal of Coal Geology》2005,62(4):250-258

A set of Pennsylvanian coals from the North American coal basins, ranging in vitrinite reflectance from 0.65% to 1.75%, was examined, with special emphasis on the optical properties of pseudovitrinite. The results suggest that pseudovitrinite originates from the same material as telocollinite. Slits in the pseudovitrinite seem to have originated in situ due to low-temperature oxidation of woody material; their opening might have been facilitated by devolatilization during coalification. The dominant orientation of the slits is perpendicular to bedding. The intensity and orientation of the slits in pseudovitrinite could be important factors in predicting coalbed gas extraction from coal.  相似文献   

Preservation of coal-waste geochemical markers in vegetation and soil on self-heating coal-waste dumps in Silesia,Poland     

《Chemie der Erde / Geochemistry》2016,76(2):211-226

Occurrence and distributions of geochemical markers on vegetation and in soils covering two self-heating coal waste dumps were investigated with gas chromatography-mass spectrometry (GC–MS) and compared with those of bitumen expelled on the coal waste dump surface. Presence of biomarkers, alkyl aromatic hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), and such polar compounds as phenols indicate that components of self-heating coal wastes indeed migrate to soils and plants surface and their characteristic fingerprints can be applied in passive monitoring to investigate migration of contaminants from self-heating coal wastes. Moreover, results allow to discriminate between the Upper- and Lower Silesian coal basins, notwithstanding value shifts caused by heating. Mechanisms enabling the migration of geochemical compounds into soils include mixing with weathered coal-waste material, transport in gases emitted due to self-heating and, indirectly, by deposition of biomass containing geochemical substances. Transport in gases involves mostly lighter compounds such as phenols, methylnaphthalenes, methylbiphenyls, etc. Distributions and values of geochemical ratios are related to differences in their boiling temperatures in the case of lighter compounds but preserve geochemical features in the case of heavier compounds such as pentacyclic trierpanes.  相似文献