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《International Journal of Coal Geology》1988,10(4):361-382
The coal deposit of Tibita is located 90 km NNE of Bogotá and is part of the more than 600-km-long coal belt of Colombia's East Cordillera. There are up to 10 mineable coal seams of around 1 m thickness each within the Upper Cretaceous/Early Tertiary Guaduas formation. The coal measures were folded during the Andean orogeny and were preserved in SW-NE-extending synclines. Despite its low rank (35–45% VM) some of the coal possesses good coking properties. The exinite-poor coal shows a number of petrographic pecularities. It largely consists of the rare microlithotype vitrinertite and is lacking in durite and clarodurite. Macroscopically, the coal is mostly homogeneous. Two major lithotypes are described here, i.e. layered and unlayered coal. It was by means of microlithotype analysis, that whole-seam-sample sequences of several boreholes could be correlated successfully. Thus coal reserves could be reliably estimated. 相似文献
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Inductively coupled plasma mass spectrometry, inductively coupled plasma optical emission spectroscopy, hydride generation-atomic fluorescence spectrometry, emission spectrometry, X fluorescence spectrometry, and X-ray diffraction were employed to study the geochemistry and mineralogy of coal gangues from Nos. 2, 3, and 8 coal seams of the Du’erping coal mine, Xishan coalfield, Taiyuan, Shanxi Province. The study revealed that compared with the sedimentary cover, upper continent crust, Carboniferous-Permian coal from North China, as well as most coal in China, coal gangues from Nos. 2 and 3 coal seams are rich in Li, Be, Sc, Cr, Cu, Ga, Ba, Th, Nb, Cd, Pb, Ta and rare-earth elements, and coal gangues from No. 8 coal seam are rich in Li, Sc, V, Cr, Ga, U, and rare-earth elements. Compared with the Carboniferous-Permian coal from North China and most coal in China, coal gangues from Nos. 2, 3 and 8 seams are rich in Rb, V, Cs and Sr. Therefore, The Du’erping coal gangues in the Xishan coalfield are rich in most hazardous trace elements and rare-earth elements, wherein the contents of Ga and Li reach the industrial grade and have significance for industrial utilization. On the whole, coal gangues of the Shanxi Formation from the Permian are rich in more trace elements than those of the Carboniferous Taiyuan Formation. The distributions of REE show obviously dipping rightwards with negative Eu anomalies. The contents of rare-earth elements in the three seams are quite different. All of the above indicate that the source of the rare-earth elements is terrigenous debris. Minerals in No. 2 seam identified by X-ray diffraction mainly include quartz, kaolinite, in addition to calcite, pyrite, apatite, epidote, and epsomite. No. 3 seam mainly contains quartz, kaolinite, in addition to a small amount of sodium feldspar, calcium nitrate, iron ore, gypsum, and vivianite. No. 8 seam mainly contains kaolinite, dickite, quartz, illite, and a small amount of hematite and U. The correlations between major elements and trace elements in coal gangues of the Du’erping coal mine analyzed by using SPSS (Statistical Product and Service Solutions) indicate that the trace alkali elements and rare-earth elements occur mainly in such clay minerals as kaolinite. 相似文献
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The Peoples' Republic of China produces and consumes the largest quantity of coal in the world; about 2.19 billion tons of coal were produced in 2005. It is estimated that coal consumption will reach 7 billion tons by 2020. Although the nationwide percent… 相似文献
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Much of the coal consumed in the US since the end of the last century has been produced from the Pennsylvanian strata of the Appalachian basin. Even though quantities mined in the past are less than they are today, this basin yielded from 70% to 80% of the nation's annual coal production from the end of the last century until the early 1970s. During the last 25 years, the proportion of the nation's coal that was produced annually from the Appalachian basin has declined markedly, and today it is only about 40% of the total. The amount of coal produced annually in the Appalachian basin, however, has been rising slowly over the last several decades, and has ranged generally from 400 to 500 million tons (Mt) per year.A large proportion of Appalachian historical production has come from relatively few counties in southwestern Pennsylvania, northern and southern West Virginia, eastern Kentucky, Virginia and Alabama. Many of these counties are decades past their years of peak production and several are almost depleted of economic deposits of coal. Because the current major consumer of Appalachian coal is the electric power industry, coal quality, especially sulfur content, has a great impact on its marketability. High-sulfur coal deposits in western Pennsylvania and Ohio are in low demand when compared with the lower sulfur coals of Virginia and southern West Virginia. Only five counties in the basin that have produced 500 Mt or more exhibit increasing rates of production at relatively high levels. Of these, six are in the central part of the basin and only one, Greene County, Pennsylvania, is in the northern part of the basin. Decline rate models, based on production decline rates and the decline rate of the estimated, “potential” reserve, indicate that Appalachian basin annual coal production will be 200 Mt or less by the middle of the next century. 相似文献
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《中国地球化学学报》2006,(Z1)
With increasing use of coal, the growing impact on the environment from potentially hazardous trace elements becomes a great concern. Southwestern Guizhou, China, is a typical area of endemic arsenosis related to coal combustion. The use of locally mined,… 相似文献
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《Geochimica et cosmochimica acta》1987,51(6):1467-1475
The forms of non-pyritic Fe in a suite of Victorian brown coals have been determined by 57Fe Mössbauer analysis. The dominant Fe phase is a poorly-ordered ferric oxyhydroxide with a magnetic ordering temperature of (530 ± 50) K and particle size of approximately 50 Å. Upon exposure of the coal to air, this phase slowly crystallises to goethite. Most of the remaining Fe occurs as a high-spin Fe(II) species attributed to dissolved and hence mobile, Fe(II) humate, which precipitates as the ferric oxyhydroxide to an extent determined by the pH. A third species, present in a much lower concentration, appears to exhibit a transition from low-spin to high-spin Fe(II) as water is removed from the coal. 相似文献
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Harvey E. Belkin Susan J. Tewalt Robert B. Finkelman Baoshan ZHENG Daishe WU Shehong LI Jianming ZHU Binbin WANG 《中国地球化学学报》2006,25(B08):52-52
The Peoples＇ Republic of China produces and consumes the largest quantity of coal in the world; about 2.19 billion tons of coal were produced in 2005. It is estimated that coal consumption will reach 7 billion tons by 2020. Although the nationwide percentage of electrical production from coal is falling due to increased coal-fired power generation efficiency and alternative sources, China will bum more coal than any other country for the foreseeable future. China also is estimated to be the largest producer of Hg emissions （Dastoor and Larocque, 2004, Atmos. Envirn. 38：147-161）. A recent comprehensive study of anthropogenic Hg emissions in China （Streets et al., 2005, Atmos. Envirn. 39：7789-7806） produced a figure of 536 tons of Hg for the year 1999 with coal combustion （all types） accounting for 38% of the total. Atmospheric Hg emission is an international problem as the upper atmosphere provides effective global transport of mercury. Although the estimates vary, China produces about three times more Hg/t of coal burnt than the USA because of the lack of modem technology for pollution control and limited use of cleaned coal. Knowledge of the mercury content, mode of occurrence, and regional distribution in Chinese coal is vital in order to assess the global atmospheric contribution from Chinese coal combustion. 相似文献
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Mining activities impact the nearby environment, causing the so-called mining hazards. The land subsidence phenomena caused by the dewatering of the mines are listed among the mining-induced catastrophic geohazards slowly affecting extensive areas around the opencasts. These large-scale geo-hazards are related to both hydrogeological and geotechnical factors, and they cause irreversible damages. The research presented aims to clarify all the components of the phenomenon and to establish the proper modelling procedure for the study of its mechanism. The site under investigation is the area extending at the west—northwest of the Amyntaio opencast coal mine at Florina Prefecture, Northern Greece. The overexploitation of the aquifers for the protection of the slopes turned the opencast to a large-diameter well, draining the surrounding area. The extensive land subsidence phenomena extend 3–4 km around the mine causing severe damages in two villages. The established results can be used for monitoring and predicting the impact of the particular mining hazard on the natural and human environment, without precluding further exploitation and mining of the energy resources. 相似文献
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Recent researches on Au in coal ash were summarized in this paper, including the distribution law and the migration rule of gold in coal ash, as well as the influencing factors on volatility and use feasibility of Au in the progress of coal combustion. Au content in coal ash is much higher than that in the raw coal in most cases worldwide, only a small number of opposite cases are found in certain places. Occurrence of Au in coal, geological-geochemical environment of coal-forming and combustion conditions are the main factors controlling the volatility of gold in coal combustion, while the occurrence of Au in coal dominates the redistribution of Au. Through preliminary calculation, gold in coal ash is expected to have a considerable utilization potential in the southwestern Guizhou Province. 相似文献
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Xi HUANG Jisen DAI Robert B. Finkelman 《中国地球化学学报》2006,25(B08):216-217
Backgrounds： Coal is and will remain a major energy resource worldwide with P.R. China and the U.S. the leading producers. It has long been known that coal mining causes health problems such as coal workers＇ pneumoconiosis （CWP） and chronic obstructive pulmonary disease （e.g., emphysema）. Yet, there are no accurate methods for predicting their occurrence. The goals of the present study are to determine whether bioavailable iron （BAI） is the active component in coal dust-induced lung diseases and to develop a model using BAI for the prediction of coal＇s pneumoconiotic potency. Methods： Thirty coal samples from Utah （UT）, West Virginia （WV） and Pennsylvania （PA） coalmine regions with a low, moderate, and high prevalence of CWP, respectively, 相似文献
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V. Z. Khilimonyuk G. P. Pustovoit M. V. Filatova 《Moscow University Geology Bulletin》2011,66(3):207-212
A quantitative estimate of the influence on the temperature mode of perennially frozen rocks in the Pechorsk coal basin caused
by pollution of the surface by coal dust was undertaken. 相似文献
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Ground subsidence induced by extraction of coal seam belowground brings about changes in territorial environment. This occurs in two forms, namely, trough and pot-hole subsidence. Pot-hole subsidence is extremely hazardous as it does not give any prior indication before its occurrence. Several pot-holes have occurred in the recent past in the coal mines of South Eastern Coalfields Limited and called for a specific study to develop an in-depth understanding of various parameters influencing the pot-hole occurrence for formulating the basis of different predictive models. These critical parameters have been compiled and analysed for seven mines located in different areas of SECL, a subsidiary of Coal India Limited. Multiple regression and artificial neural network (ANN) techniques were used for the preparation of the predictive models to calculate pot-hole depth under different conditions. Different conditions considered in the study are development and depillaring, presence and absence of faults and water bodies. This paper presents the results of the studies carried out in Indian mines representing different geo-mining conditions along with the pot-hole depth prediction models developed. The developed models were validated for a few new cases with the model results matching (within 10 % error in the case of ANN model) with the actual pot-hole depth measured. More varied data sets can fine tune the developed models further. 相似文献
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《中国地球化学学报》2006,(Z1)
The geochemistry theory can provide information about the distribution, contents and migration in nature of the chemical elements in minerals, rocks. soils, waters, atmospheres, etc. Therefore, it has been applied extensively. Nowadays the petroleum suppl… 相似文献
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F. Doulati Ardejani B. Jodeiri Shokri M. Bagheri E. Soleimani 《Environmental Earth Sciences》2010,61(8):1547-1560
Acid mine drainage (AMD) pollution is considered to be the most serious water pollution problem in mining areas. AMD containing
iron sulfates and other components can affect the receiving water bodies. Pyrite oxidation and AMD generation can be considered
as important processes that may take place in the wastes produced by coal mining and coal washing operations in the Golestan
province (northeast Iran). The study area is characterized by appropriate atmospheric conditions that favor pyrite oxidation
and the presence of a large amount of water bodies. This study attempts to consider pyrite oxidation and AMD generation in
the Azad shahr–Ramian region. The impact of AMD on the quality of the surface water bodies was investigated by taking samples
and analyzing them for hydro-geochemical parameters. Stiff and Piper diagrams were used to represent chemical analyses of
water samples. The coal samples taken from different depths at four points on two different coal waste dumps were analyzed
to find the fraction of pyrite that remained in the waste particles to investigate the pyrite oxidation process. A computational
fluid dynamic package called PHOENICS was used to model pyrite oxidation process numerically. The results obtained from the
geochemical analyses of water and coal samples and numerical simulation show pyrite oxidation and acid generation in the region.
However, the presence of carbonate rocks raised the pH of the water samples. The drainages of the Razi mine may be recognized
as natural alkaline mine drainages. 相似文献
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