首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 23 毫秒
1.
This study is related to four Jurassic-age bituminous coal (0.69–1.02 Ro%) samples collected from coal mines from the west, central and east of central, Alborz in northern Iran. Geological settings played key roles in determining the geochemistry and mineralogy of coals from the central Alborz region of northern Iran. The mineralogy of coals from the eastern part of the region is dominated by kaolinite; halloysite; and carbonates such as calcite, dolomite/ankerite, and siderite. The coals were deposited in a lacustrine environment. In the western part of the region, where the depositional setting was also lacustrine with volcanic input and tonstein deposition (glass shards present), the coal primarily contains kaolinite (68%) and fluorapatite (26%). In contrast, coal from the central part of the region, which was deposited in a terrestrial environment and on eroded limestone and dolomite rocks, is dominated by dolomite (98%) with little input by kaolinite. These coals have low sulphur (0.35–0.70 wt.%), which is mostly in the organic form (0.34–0.69 wt.%). Pyritic sulphur is detected only in one coal and in small quantities. The boron contents of these coals range from 9 to 33 mg/kg, indicating that deposition occurred in a fresh water environment. Coal with higher concentrations of Ba, Sr, and P contain fluorapatite and goyazite–gorceixite series [BaAl3 (PO4)2 (OH)5, H2O] minerals, which indicates volcanoclastic input. Compared to world coal averages, these coals exhibit low concentrations of elements of environmental concern, such as As (1.3–5.9 mg/kg), Cd (< 0.02–0.06 mg/kg), Hg (< 0.01–0.07 mg/kg) Mo (< 0.6–1.7 mg/kg), Pb (4.8–13 mg/kg), Th (0.5–21 mg/kg), Se (< 0.2–0.8 mg/kg) and U (0.2–4.6 mg/kg). Two of the northern Iranian coals have concentrations of Cl (2560 and 3010 mg/kg) that are higher than world coal average.  相似文献   

2.
Composition and quality of coals in the Huaibei Coalfield, Anhui, China   总被引：3，自引：0，他引：3  
The Huaibei Coalfield, Anhui Province, China, is one of the largest coalfields in China. The coals of Permian age are used mainly for power generation. Coal compositions and 47 trace elements of the No. 10 Coal of the Shanxi Formation, the No. 7, 5, and 4 Coals of the Lower Shihezi Formation, and the No. 3 Coal of the Upper Shihezi Formation from the Huaibei Coalfield were studied. The results indicate that the Huaibei coals have low ash, moisture, and sulfur contents, but high volatile matter and calorific value. The ash yield increases stratigraphically upwards, but the volatile matter and total sulfur contents show a slight decrease from the lower to upper seams. Magmatic intrusion into the No. 5 Coal resulted in high ash, volatile matter, and calorific value, but low moisture value in the coal. Among the studied 47 trace elements, Ba, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Th, U, V, and Zn are of environmental concerns. Four elements Hg, Mo, Zn, and Sb are clearly enriched in the coals as compared with the upper continental crust.  相似文献   

3.
Twenty-nine low sulfur coal samples were selected to determine the magnitude and variability of mercury (Hg) content in a well-documented stratigraphy system including ten continuous coal seams in Zhuji Coal Mine, Huainan Coalfield, Anhui Province, North China. Mercury content of samples was measured on a direct mercury analyzer and confident results were obtained as evaluated by standard references, sample replicates and procedural blanks. The calculated overall mine average Hg content is 71.19?±?9.28 ng/g based on seam averages and weighting by the estimated reserve of each coal seam. The estimated Hg emission potential for Huainan coalfield is obviously lower than that calculated from coal emission factor in industrial use. An increasing trend of Hg content with the evolution of depositional environment was observed from Nos. 3 to 11-2 coal seams. Combining the evidence of sedimentology and paleontology, a better understanding was gained of the mechanism of Hg sequestration in specific coal benches. A large portion of Hg residing in the low sulfur coals presumably integrated to the functional groups of organic constitution, whereas pyrite was generally abundant in the high sulfur coals.  相似文献   

4.
淮北煤田煤中汞的赋存状态   总被引：6，自引：0，他引：6  
系统采集淮北煤田10、7、5、4和3煤层的29个煤样品, 采用逐级化学提取方法研究了煤中汞的赋存状态, 根据提取步骤和汞的特性, 将煤中的汞分为水溶态、离子交换态、有机态、碳酸盐结合态、硅酸盐结合态和硫化物结合态, 利用Flow Injection Mercury System(FIMS)分析了样品中总汞和不同形态中汞的含量.测试结果表明, 与华北石炭-二叠纪煤、中国煤以及美国煤含量相比较, 淮北煤田煤中汞的含量明显富集.逐级化学提取实验结果和煤中汞与硫、灰分的相关分析结果表明, 岩浆的侵入对煤中汞的赋存状态有较大的影响, 不受岩浆侵入影响的10、4和3煤层煤中的汞主要以有机态和硫化物结合态存在, 受岩浆侵入影响的5和7煤层中的汞主要以硅酸盐结合态存在.   相似文献   

5.
The paper summarizes data on the Pleistocene combustion metamorphic complexes of the Kuznetsk Coal Basin. Paralava and clinker samples are dated by 40Ar/39Ar incremental heating. The 40Ar/39Ar ages of the combustion metamorphic rocks permit reconstructions of the succession of renewed activity of ancient faults in the Salair zone and age estimates for the evolution of the present-day drainage network. Cross sections of burned rocks from the western margin and center of the Kuznetsk Basin are compared. The geologic factors of coal ignition risks are analyzed. On the western margin of the Kuznetsk Basin, paleofires occurred in steeply dipping thick seams with predominant crushed vitrain–clarain coal, which has a high oxygen and methane adsorption capacity. Highly denuded high-temperature combustion metamorphic complexes are most often localized in the arches of slightly broken anticlines. Oxygen was supplied to the coals during the Late Cenozoic renewed fault activity and the subsequent erosion of the sediments. The natural fires in the area were a result of external rather than spontaneous ignition. The depths of the paleofires (up to 200 m) indicate that they occurred in a warm and dry climate. In the center of the Kuznetsk Basin, dispersed fire foci appeared in seams of self-igniting coals with the erosion propagation of the current drainage network. The combustion metamorphic complexes here are partly eroded and consist mostly of clinkers with a low degree of alteration. The 40Ar/39Ar ages and geological data indicate that the earliest large-scale combustion events on the western periphery of the basin occurred in the Eopleistocene (1.3–0.9 Ma).The oldest 40Ar/39Ar age of a coal fire episode (1.7 ± 0.3 Ma) might be the upper age boundary of the altitude differentiation of topography, which corresponds to the renewed activity of the Tyrgan and Afonino–Kiselevsk faults. The later synchronous combustion events on the western margin (0.2 ± 0.1 Ma) and in the center of the basin (0.13–0.02 Ma), most probably, occurred during the Kazantsevian interglacial, which gave rise to the present-day drainage network.  相似文献   

6.
《Applied Geochemistry》2006,21(11):1940-1954
Speciation and microbial transformation of Hg was studied in mine waste from abandoned Hg mines in SW Texas to evaluate the potential for methyl-Hg production and degradation in mine wastes. In mine waste samples, total Hg, ionic Hg2+, Hg0, methyl-Hg, organic C, and total S concentrations were measured, various Hg compounds were identified using thermal desorption pyrolysis, and potential rates of Hg methylation and methyl-Hg demethylation were determined using isotopic-tracer methods. These data are the first reported for Hg mines in this region. Total Hg and methyl-Hg concentrations were also determined in stream sediment collected downstream from two of the mines to evaluate transport of Hg and methylation in surrounding ecosystems. Mine waste contains total Hg and methyl-Hg concentrations as high as 19,000 μg/g and 1500 ng/g, respectively, which are among the highest concentrations reported at Hg mines worldwide. Pyrolysis analyses show that mine waste contains variable amounts of cinnabar, metacinnabar, Hg0, and Hg sorbed onto particles. Methyl-Hg concentrations in mine waste correlate positively with ionic Hg2+, organic C, and total S, which are geochemical parameters that influence processes of Hg cycling and methylation. Net methylation rates were as high as 11,000 ng/g/day, indicating significant microbial Hg methylation at some sites, especially in samples collected inside retorts. Microbially-mediated methyl-Hg demethylation was also observed in many samples, but where both methylation and demethylation were found, the potential rate of methylation was faster. Total Hg concentrations in stream sediment samples were generally below the probable effect concentration of 1.06 μg/g, the Hg concentration above which harmful effects are likely to be observed in sediment dwelling organisms; whereas total Hg concentrations in mine waste samples were found to exceed this concentration, although this is a sediment quality guideline and is not directly applicable to mine waste. Although total Hg and methyl-Hg concentrations are locally high in some mine waste samples, little Hg appears to be exported from these Hg mines in stream sediment primarily due to the arid climate and lack of precipitation and mine runoff in this region.  相似文献   

7.
The Great Falls-Lewistown Coal Field (GFLCF) in central Montana contains over 400 abandoned underground coal mines, many of which are discharging acidic water with serious environmental consequences. Areas of the mines that are completely submerged by groundwater have circum-neutral pH and relatively low concentrations of metals, whereas areas that are only partially flooded or freely draining have acidic pH (< 3) and high concentrations of metals. The pH of the mine drains either decreases or increases after discharging to the surface, depending on the initial ratio of acidity (mainly Al and Fe2+) to alkalinity (mainly HCO3?). In acidic, Fe-rich waters, oxidation of Fe2+ after exposure to air is microbially catalyzed and follows zero-order kinetics, with computed rate constants falling in the range of 0.97 to 1.25 mmol L? 1 h? 1. In contrast, Fe2+ oxidation in near-neutral pH waters appears to be first-order with respect to Fe2+ concentration, although insufficient data were collected to constrain the rate law expression. Rates of Fe2+ oxidation in the field are dependent on temperature such that lower Fe2+ concentrations were measured in down-gradient waters during the day, and higher concentrations at night. Diel cycles in dissolved concentrations of Zn and other trace metals (Mn, Ni) were also noted for down-gradient waters that were net alkaline, but not in the acidic drains.The coal seams of the GFLCF and overlying Cretaceous sandstones form a perched aquifer that lies ~ 50 m above the regional water table situated in the underlying Madison Limestone. The δD and δ18O values of flooded mine waters suggest local derivation from meteoric water that has been partially evaporated in agricultural soils overlying the coal mines. The S and O isotopic composition of dissolved sulfate in the low pH mine drains is consistent with oxidation of biogenic pyrite in coal under aerated conditions. A clear distinction exists between the isotopic composition of sulfate in the acid mine waters and sulfate in the adjacent sedimentary aquifers, making it theoretically possible to determine if acid drainage from the coal mines has leaked into the underlying Madison aquifer.  相似文献   

8.
The elemental composition of high temperature ash (750°C) and forms of S were studied in 25 coal seams from the Escucha Formation (Middle Albian) in the Teruel Mining District, northeast Spain. The principal analytical method was ICP-MS, but ICP-ES was also used in the determination of some trace elements. The analytical data show wide ranges of trace element cotnents among the coal seams studied, even in the vertical profile of a single coal seam. These wide ranges of the trace element concentrations are attributed to both syngenetic and epigenetic processes.When a comparison was made between the average trace element contents of the Teruel Mining District coals, and those of the average content in worldwide coals, the Teruel coals show slightly higher concentrations of Be and U, and lower concentrations of Ba, Cd, Mn, Pb, Sr and Zr. Further, three main groups of trace elements were differentiated on the basis of the inorganic/organic association: (1) trace elements with inorganic affinity; Ba, Ce, Co, Cr, La, Mn, Ni, Rb and Zr. Between these, Ba, Ce, Cr and Rb show a well defined correlation with the clay mineral content, and Co and Ni with pyritic-S content; (2) trace elements with an intermediate (mixed) affinity; As, Cd, Cu, Dy, Er, Eu, Gd, Ge, Ho, Lu, Mo, Nd, Pb, Pr, Sb, Sm, Sr, Tb, Th, Tm, U, Yb and Zn. In this group, As, Cd, Cu, Ge, Mo, Th, U and Zn show a weak trend associated with the mineral matter and Sr with the organic matter; and (3) Be shows an organic affinity. The high mineral matter content (21.3% HTA) of the Teruel coals may account for the great number of elements with inorganic affinity. This classification represents a general trend, but the results show that the affinities of some trace elements (e.g. As, Sb and Zn) may vary from one coal seam to another in the Teruel Mining District.  相似文献   

9.
系统采集淮北卧龙湖煤矿岩浆蚀变煤层中岩浆岩、煤及顶底板岩石样品,测试分析了样品中汞、灰分、挥发分、水 分以及各形态硫的含量,探讨了岩浆蚀变煤层中汞的分布与赋存特征。结果表明：（1） 岩浆侵入导致煤中灰分升高,挥发 分降低,煤中硫主要以黄铁矿硫和有机硫存在;（2） 岩浆侵入导致煤中汞的富集,卧龙湖煤矿岩浆蚀变煤层中汞的平均含 量高达0.23×10-6,是华北石炭-二叠纪煤、中国煤以及美国煤中汞的平均含量的1.4 倍,1.2 倍和1.3 倍;（3） 煤中汞的含量 随离岩浆侵入体距离增大有逐渐降低的趋势,但在煤岩接触带附近,汞在岩浆侵入体上方和下方的煤中呈现不同的分布特 征;（4） 煤中的汞主要以无机结合态的形式存在,且大部分赋存在煤中的黄铁矿中,同时亦存在与有机硫结合的汞。岩浆 热液对煤层的侵入,导致煤质以及煤中汞的含量和赋存方式发生了显著变化。  相似文献   

10.
The petrological, geochemical, and mineralogical compositions of the coal-hosted Jurassic uranium ore deposit in the Yili Basin of Xinjiang province, northwestern China, were investigated using optical microscopy and field emission-scanning electron microscopy in conjunction with an energy-dispersive X-ray spectrometer, as well as X-ray powder diffraction, X-ray fluorescence, and inductively coupled plasma mass spectrometry. The Yili coal is of high volatile C/B bituminous rank (0.51–0.59% vitrinite reflectance) and has a medium sulfur content (1.32% on average). Fusinite and semifusinite generally dominate the maceral assemblage, which exhibits forms suggesting fire-driven formation of those macerals together with forms suggesting degradation of wood followed by burning. The Yili coals are characterized by high concentrations of U (up to 7207 μg/g), Se (up to 253 μg/g), Mo (1248 μg/g), and Re (up to 34 μg/g), as well as As (up to 234 μg/g) and Hg (up to 3858 ng/g). Relative to the upper continental crust, the rare earth elements (REEs) in the coals are characterized by heavy or/and medium REE enrichment. The minerals in the Yili coals are mainly quartz, kaolinite, illite and illite/smectite, as well as, to a lesser extent, K-feldspar, chlorite, pyrite, and trace amounts of calcite, dolomite, amphibole, millerite, chalcopyrite, cattierite, siegenite, ferroselite, krutaite, eskebornite, pitchblende, coffinite, silicorhabdophane, and zircon. The enrichment and modes of occurrence of the trace elements, and also of the minerals in the coal, are attributed to derivation from a sediment source region of felsic and intermediate petrological composition, and to two different later-stage solutions (a U–Se–Mo–Re rich infiltrational and a Hg–As-rich exfiltrational volcanogenic solution). The main elements with high enrichment factors, U, Se, As, and Hg, overall exhibit a mixed organic–inorganic affinity. The uranium minerals, pitchblende and coffinite, occur as cavity-fillings in structured inertinite macerals. Selenium, As, and Hg in high-pyrite samples mainly show a sulfide affinity.  相似文献   

11.
《Applied Geochemistry》2005,20(3):627-638
Concentrations of total Hg and methylmercury (MMHg) in riparian soil, mine-waste calcine, sediment, and moss samples collected from abandoned Hg mines in Wanshan district, Guizhou province, China, were measured to show regional dispersion of Hg-contamination. High total Hg and MMHg concentrations obtained in riparian soils from mined areas, ranged from 5.1 to 790 mg kg−1 and 0.13 to 15 ng g−1, respectively. However, total Hg and MMHg concentrations in the soils collected from control sites were significantly lower varying from 0.1 to 1.2 mg kg−1 and 0.10 to 1.6 ng g−1, respectively. Total Hg and MMHg concentrations in sediments varied from 90 to 930 mg kg−1 and 3.0 to 20 ng g−1, respectively. Total Hg concentrations in mine-waste calcines were highly elevated ranging from 5.7 to 4400 mg kg−1, but MMHg concentrations were generally low ranging from 0.17 to 1.1 ng g−1. Similar to the high Hg concentrations in soil and sediments, moss samples collected from rocks ranged from 1.0 to 95 mg kg−1 in total Hg and from 0.21 to 20 ng g−1 in MMHg. Elevated Hg concentrations in mosses suggest that atmospheric deposition might be an important pathway of Hg to the local terrestrial system. Moreover, the spatial distribution patterns of Hg contamination in the local environment suggest derivation from historic Hg mining sites in the Wanshan area.  相似文献   

12.
The Elk Valley coalfield of British Columbia is one of the major coal producing areas in Canada. The coals are of Cretaceous and Jurassic–Cretaceous age and range in rank from high-volatile to low-volatile bituminous (%Romax: 0.8–1.6). Coal seams from outcrops and active mines in this coalfield were analysed for rank and maceral composition using reflected light microscopy, for geochemistry using AAS, INAA, and ICPES, and also by proximate and ultimate analyses. The Elk Valley coal seams contain low average concentrations of hazardous elements such as As, Mo, Pb, and Se. However, there are seams that contain relatively high concentrations of some of these elements, such as 8 mg/kg and 108 mg/kg of arsenic. When the geochemistry of coal seams is compared within the different parts of the coalfield, the elemental composition amongst the seams from various sections located in the central area of the coalfield is similar. Coal seams in the northern area of the coalfield have different geochemistry than coal seams in other areas of the coalfield; seams in the northern area have much higher As, Br, Cr, Cu, Fe, K, and Na content, but contain less Ca.  相似文献   

13.
Alberta has vast coal resources that may be a potential source of coalbed methane (CBM). Exploration and research are currently underway in the province to quantify gas potential, identify key geological factors that maximize CBM potential, and identify the ‘most favourable’ areas for CBM production potential.There are four main coal zones within the Plains and Foothills of Alberta. The Ardley Coal Zone of the Plains is undergoing CBM exploration and production piloting. Much of this effort is within the west-central Pembina area. Horseshoe Canyon Formation coals of south-central Alberta were initially thought to have gas concentrations too low to be economic CBM producers. It is these coals, however, that host Alberta's first commercial CBM production project. Although similar in both geographic distribution and coal quality to Horseshoe Canyon coals, not much is known regarding the gas potential of underlying coals of the Belly River Group. The deeper Mannville coals have some of the highest gas concentrations of Alberta coals; however, they are also relatively deep and have lower permeability than the overlying Belly River, Horseshoe Canyon and Ardley coals.Maximum gas-in-place for the Plains and Foothills has been estimated to be greater than 500 trillion cubic feet (1.42 * 1013 m3). Although this number is very large, little is known as to how much of this huge resource is actually producible. A key challenge to producibility in Alberta has been the generally low permeability of coals with the highest gas concentrations (Mannville coals), and the moderate to low gas concentrations of higher permeability coals (Horseshoe Canyon and Ardley coals).Regionally, coal distribution and average gas-in-place concentrations are calculated for the Alberta Plains. Identifying and explaining local areas with favourable CBM production characteristics within the regional setting is necessary to establish economic CBM plays within Alberta. There are currently several pilots and numerous exploration efforts underway in the province to demonstrate production potential.This study integrates existing data with new data collected from key areas that show favourable CBM potential. There is great opportunity for CBM development in Alberta. Local areas have enhanced characteristics favourable to production. Ongoing geological investigations are needed to identify characteristics that will serve as an exploration tool for future CBM discoveries.  相似文献   

14.
Complete sorption isotherm characteristics of methane and CO2 were studied on fourteen sub-bituminous to high-volatile bituminous Indian Gondwana coals. The mean vitrinite reflectance values of the coal samples are within the range of 0.64% to 1.30% with varying maceral composition. All isotherms were conducted at 30 °C on dry, powdered coal samples up to a maximum experimental pressure of ~ 7.8 MPa and 5.8 MPa for methane and CO2, respectively.The nature of the isotherms varied widely within the experimental pressure range with some of the samples remained under-saturated while the others attained saturation. The CO2 to methane adsorption ratios decreased with the increase in experimental pressure and the overall variation was between 4:1 and 1.5:1 for most of the coals. For both methane and CO2, the lower-ranked coal samples generally exhibited higher sorption affinity compared to the higher-ranked coals. However, sorption capacity indicates a U-shaped trend with rank. Significant hysteresis was observed between the ad/desorption isotherms for CO2. However, with methane, hysteresis was either absent or insignificant. It was also observed that the coal maceral compositions had a significant impact on the sorption capacities for both methane and CO2. Coals with higher vitrinite contents showed higher capacities while internite content indicated a negative impact on the sorption capacity.  相似文献   

15.
Rare metals in coal deposits have attracted much attention in recent years because of their potential economic significance. This paper reports the abundance and enrichment origin of rare metals in the Late Permian coals (K1 and K2 Coals) of the Moxinpo Coalfield, Chongqing, southwestern China. The K1 Coal is characterized by highly-elevated concentrations of U-Re-V-Cr-Se and Nb(Ta)-Zr(Hf)-REE assemblages; the latter assemblage is also enriched in the K2 Coal. The high temperature ash (815 °C) of the K1 Coal is enriched in V, Cr, Se, Re, U and REE; the ash of the K2 Coal, and also the floor strata of each seam, are enriched in REE, potentially making all of the units economically viable sources for these elements.The minerals in the K1 Coal are mainly represented by kaolinite, illite and mixed-layer illite/smectite, and pyrite, while the minerals in the K2 Coal consist mainly of kaolinite and tobelite [(NH4,K)Al2(AlSi3O10)(OH)2]. Authigenic roscoelite [K(V3 +,Al)2(AlSi3O10)(OH)2] is commonly observed in the K1 Coal under the SEM, and was probably formed by interaction of kaolinite with V derived from permeating U-Re-V-Cr-Se-rich solutions during early diagenesis. The tobelite enriched in the K2 Coal was formed by reaction between kaolinite already present in the coal and NH4 + derived from decomposition of the organic matter during hydrothermal alteration at a relatively high temperature.The mafic tuffs directly underlying the K1 Coal and containing limestone residual breccias not only served as the substrate for coal accumulation but also as the source of sediment from the uplifted areas around the coal basin. The latter is indicated by low Al2O3/TiO2 ratios (from 10.09 to 14.24), positive Eu anomalies enrichment of medium rare earths (relative to upper continental crust), and detrital calcite of terrigenous origin. The highly-elevated concentrations of U-Re-V-Cr-Se assemblages in the coal were derived from exfiltrational hydrothermal solutions and were then deposited in a euxinic environment. The terrigenous materials in the K2 Coal, however, were derived from felsic-intermediate rocks at the top of the Kangdian Upland, although the elevated concentrations of Nb(Ta)-Zr(Hf)-REE assemblages are attributed to the input of hydrothermal solutions.  相似文献   

16.
古交邢家社勘探区煤中镓的分布及其地质影响因素   总被引：1，自引：0，他引：1  
依据煤炭资源勘探资料,探讨了山西古交矿区邢家社勘探区石炭-二叠系煤中镓的分布状况及其地质影响因素。结果显示:研究区煤中镓的加权平均质量分数为15.87×10-6,比全球平均值要高0.5~3倍;煤层层位降低,镓含量呈明显的递减趋势。同时,煤中镓含量与灰分产率、灰分组成、硫含量及煤层厚度之间也有明显的相关关系。这些特征表明,区内煤中镓的矿物载体主要为粘土矿物,水动力较强和还原性较弱的泥炭沼泽条件可能有利于镓在煤中富集,且成煤期地壳的稳定程度也可通过一定方式影响到煤中镓的富集。   相似文献   

17.
Coal is present in the Alberta Foothills/Mountains in five zones: the Kootenay, Gething, Gates, Brazeau and Coalspur coal zones. For coalbed-methane (CBM) evaluation purposes, they can be divided into shallow (less than 1000 m depth) and deep (greater than 1000 m depth) coal zones. The potential gas content of all shallow coal zones totals about 878 × 109 m3 (31 Tcf) of CBM, which is considered an inferred, initial, in-place, coalbed-methane resource estimate based on limited data. The limited amount of data on formation testing and measured gas content indicate that the inferred resource is bordering on the speculative category.The gas content of all deep coal zones (deeper than 1000 m) totals 2.8 × 1012 m3 (about 99 Tcf) of in-place coalbed-methane gas. Consequently, the total ultimate coalbed-methane resource could be 3.7 × 1012 m3 (130 Tcf). However, coalbed-methane recovery from deep coals is generally not attempted because of the high cost of drilling and the low permeability that results from high overburden load and stress.The only (limited) Foothills coalbed-methane production has been from the southern Alberta Kootenay Coal Zone, which is very prospective for coalbed-methane production. The shallow Gates Coal Zone in the central and northern Foothills is also prospective, but needs to be better tested. The best potential for coalbed methane in the Coalspur Coal Zone is in the Edson area (Entrance Syncline and Triangle Zone). The Kootenay and Gates coal zones are not well defined in the northern part of the Calgary (NTS 82O) map sheet.  相似文献   

18.
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   

19.
淮北煤田二叠纪煤中稀土元素地球化学研究   总被引：9，自引：0，他引：9  
从淮北煤田二叠系10,7,5,4和3煤层中采集34个样品,采用等离子体质谱（ICP-MS）、中子活化（INNA）、等离子体发射光谱（ICP-AES）等方法对样品中主量元素和稀土元素进行了测试,利用X射线衍射等方法对煤中矿物质及其煤质参数进行了测定。在各种测试的基础上,全面分析了稀土元素含量特征、空间分布规律、地球化学参数和分布模式,探讨了淮北煤田二叠纪煤中稀土元素的主要来源及其在煤中的主要赋存方式。研究表明：与华北和国内外其他地区相比,本区煤层中稀土元素相对富集;产于石盒子组煤中的稀土元素含量高于山两组的,在同一煤层中自下而下稀土元素含量有增高趋势,在顶底板中可能出现富集。Ce呈正异常,Eu明显负异常,不同煤层稀土元素的分布模式相似,稀土元素和灰分具有较好的正相关,∑REE与灰分、灰分中的主要元素以及典型陆源灰分中的微量元素正相关,与反映海相的低灰组分相关性较差。结合煤中矿物质的X射线衍射结果,分析获知,淮北煤田二叠纪成煤环境基本不受海水影响,稀土元素主要由陆源供给,而且主要赋存在以高岭石、伊利石为主的粘土矿物中。  相似文献   

20.
贵州六枝、水城煤田晚二叠世煤的微量元素特征   总被引：4，自引：0，他引：4  
通过对六枝和水城煤田 10个煤矿主要可采煤层的 45个煤样品的常量和微量元素系统研究 ,概括了这两个煤田煤中常量和微量元素的丰度和分布特征 ;阐述了煤中微量元素的亲合性。这两个煤田煤中的全硫含量在受海水影响的煤层中较高 (最高达 7.5 % ) ,而在非海水影响的煤层中较低 ( 0 .3% )。六枝煤田的全硫含量明显高于水城煤田。Ca-Mn-Ge的平均含量在六枝煤田较低 ,而在水城煤田相对较高。在这两个煤田和不同的煤层之间 ,煤中微量元素含量的变化较小。与世界烟煤中一般含量范围相比 ,这两个煤田的特征是 Mn,V,Cu,L i,Zr,Nb,Ta,Hf,T1,Th和 U的含量相对高。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号