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1.
It is known that the increasing use of coal as an energy source led to the growing environmental and health problems. But comprehensive knowledge of coal quality parameters may help to reduce some of these problems. The ?anakkale-?an coalfield is located …  相似文献   

2.
Coal is an important natural resource in Botswana. The best coals so far found occur in the Morupule coalfield, west of Palapye, where nearly 8000 million tons have been identified (Carney et al., 1994). In this study we investigate the environmental impact of the mining and consumption of the high-ash, medium-calorific value bituminous coal in the eastern part of Botswana, which may serve as a reference for other coal mines and coal-based power stations around the globe. More than two hundred surface soil samples and three profile soil samples were collected around Morupule Colliery, Morupule Power Station and Palapye.  相似文献   

3.
Coal combustion can mobilize trace elements by introducing them to terrestrial, aquatic and atmospheric environments, and if leached, these elements may cause the contamination of soils, surface waters and groundwater. Therefore, these elements may become a hazard to the environment because of their contribution to the formation of toxic compounds, if the ash is not utilized or disposed of properly. This possible contamination could lead to health, environmental and land-use problems. A fluid coal-t-fred thermal power plant (320 MWel) has been in operation since 2005 in Can (Canakkale-Turkey) and currently produces almost half a million tones of fly ash per year. Fly ash is classified based on the nature of constituents present. Fly ashes of Class C contain less than 70% but greater than 50% of silica, alumina, and iron oxide which are typical for the western part of Turkey. When the ash concentrations of these three constituents exceed 70%, fly is classified as F, which is representative of those, produced from Can. Fly ash is enriched in many trace elements particularly metals in this thermal power plant ash. These metals are part of the pyrite structure in the coal and become concentrated in the fly ash during the combustion process. These elements may be surface adsorbed on the glassy spherical fly ash particles. Elements that are surface adsorbed can be quite mobile.  相似文献   

4.
The focus of this study is to determine the concentrations and the distributions of elements of prime environmental concern (As, Cd, Cr, Cu Hg, Mo, Ni, Pb, Se and V) and other elements of environmental interest (B, Ba, Be, Co, Mn, U) in milled coals, power plant ashes, and stack-emitted materials from a Western Canadian power plant using bituminous coal. The concentrations of elements were determined using neutron activation analysis (NAA), Inductively Coupled Plasma Emission Spectroscopy (ICPES), and Inductively Coupled Plasma-Mass spectroscopy (ICP-MS) for most elements, Graphite Furnace Atomic Absorption (GFAA) for Pb, and Cold Vapor Atomic Absorption (CVAA) for Hg. The result of the study shows that the total rate of input is 423.5 kg/d for elements of prime environmental concern and 280 kg/d for elements of environmental interest. The concentrations of most elements in milled coal are low as compared to world coals and other Canadian milled coals. The total output of these two groups of elements is 2.9 kg/d and 110.4 kg/d, respectively. This indicates that only a small amount of the total input elements from the milled coal is emitted. Most of it is captured by the bottom and ESP ashes with the exception of the highly volatile As Hg, F, Br, and Cl. The element with highest rate of emission for elements of prime environmental concern is Se (0.73 kg/d) and B (95 kg/d) for the elements of some environmental interest.  相似文献   

5.
Coals from Guizhou Province, Southwest China, attract many researchers' attention for their high concentrations of hazardous trace elements, sulphur and mineral components. Trace elements in coals have diverse modes of occurrence that will greatly influence their migration in the process of coal preparation. Mode of occurrence is also important in determining the partitioning during coal combustion. The coal floatation test by progressive release was used to study the migration of trace elements and mineral components in the process of froth floatation. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the absolute concentrations of trace elements including As, Be, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Th, U, V and Zn in the parent coals and the floatation fractions. Precise determination of the mineral matter percentage in coals was obtained by low-temperature ashing. The mineral compositions in coals were quantified using Rietveld-based X-ray diffraction analysis package on low-temperature ash. Scanning electron microscope equipped with energy dispersive X-ray detector was used to provide information on the forms of occurrence of mineral components in coal. Five floatation fractions were obtained from the pulverized coal samples. The contents of trace elements and mineral components decrease from the first tailings to the last cleaned coal. The concentrations of trace elements and mineral components in parent coals and different floatation samples show that trace elements and mineral components are mainly concentrated in the first tailings samples. Nearly 60% of mineral components are enriched in the first tailings, whereas less than 1.3% remains in the cleaned coal. The ratio of sixteen trace elements concentrations in the first tailings to the corresponding concentrations in the cleaned coal ranges from 1.6 to 22.7. Quantitative mineralogical analysis results using the full-profile general structure analysis system (GSAS) showed that the main compositions of LTA include quartz, calcite, kaolinite, pyrite, chlorite, montmorillonite, illite, anatase and pyrite.  相似文献   

6.
Geoscience Australia and the Cooperative Research Centre for Landscape Environments and Mineral Exploration, in collaboration with State agencies are conducting a series of pilot baseline geochemical surveys (BGS). These aim to characterize regional geochemical patterns and contribute to what is presently a limited research direction in Australia. BGS can help (1) establish baselines to monitor future change; (2) target mineral exploration; (3) develop informed environmental policies; and (4) geomedical studies on plant and animal well being. In 2004-05, sampling at an average density of 1 sample per 1100 km^2, was conducted in the Gawler Craton, South Australia. In contrast to our pilot region in the Riverina of New South Wales and Victoria, the Gawler lacks well-developed drainage systems and is dominated by aeolian dunes in its western sector. One of the key aims of the Gawler study is to determine whether elemental excesses or deficiencies exist in the regolith and the implications of these for plant, animal and human health. Top (0-10 cm depth) and bottom (~55-90 cm depth) sediment samples were collected in the lower parts of 42 catchments. The compositions of the 〈75 um and 〈180 um fractions were analyzed using XRF (major and some trace elements), ICP-MS (most trace elements) and ISE (F) methods. Preliminary results show that F, Cr and V are locally elevated above national and international guideline concentrations, raising concerns that these elements may pose potential health issues. Heavy mineral fractions (density 〉2.95) in 4 samples (3 sites) are dominated by iron oxides, spinels, rutile, zircon and barite. Some Cr and V may be related to heavy minerals such as spinels, limiting their bioavailability. Cu, Se and Zn are potentially deficient in parts of the region, but once identified in agricultural areas can easily be remedied through the application of suitable fertilizers.  相似文献   

7.
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   

8.
Based on the analyses of 43 elements in 16 samples of the raw coal and feed coal collected from the northern Ordos basin and Shanxi Province, the modes of occurrence of these elements were studied using the method of cluster analysis and factor analysis, and the cleaning potential of the hazardous elements relatively enriched in the coals was discussed by analyzing six samples of the cleaned coal from the coal-washing plants and coal cleaning simulation experiments. The results shows that the elements Br and Ba show a strong affinity to the organic matter, Cs, Cd, Pb, Zn and Hg partly to the organic matter, and the other trace elements are mainly associated with the mineral matter. Cs, Mo, P, Pb, Zn and S have positive correlations with the two principal factors, reflecting the complexity of their modes of occurrence. Some elements that were thought to show a faint relationship (Be with S and Sb with carbonates) in other rocks are found to have a strong interrelation in the coals. Clay minerals (mainly k  相似文献   

9.
《中国地球化学学报》2006,25(B08):68-68
Honey is valuable food for mankind since the ancient times. It was the only sweetener till the start of the industrial sugar mass production. As honey plays an important role in our nutrition and its positive effects on health is well known, it is very important to study the nutritional properties and the origin of different honey samples. The usually determined quality parameters of honey: pH values, water content, sugar content, acidity, HMF content, enzyme activity, pollen content, amino acid content, ash content, etc. It is also important to know the content of the organic contaminants in honey. A short time ago there were some quality problems with Hungarian and Greek honey in the European Union. A toxic material (para-dichlorobensene) was found in honey originated from Greece. The amount was higher than the allowable limit in the EU. Therefore, it is necessary to build up a good and applicable traceability system for honey. During the past few years the traceability concept has become increasingly familiar in many sectors of the food industry. Traceability is an essential tool for ensuring both production and product quality. The opportunity to connect traceability with the whole documentation and control system represents an effective means for boosting the consumer's perception of a food's safety and quality. In our work we have done, which quality parameters can be used for a good identification system.  相似文献   

10.
Hazardous air pollutants, including compounds of sulfur and toxic trace elements, are emitted during coal combustion. Geochemical studies of these constituents in coals provide information about their species, regional distribution and origins. The data are useful in understanding the cause and scope of human health problems related to these hazardous elements and in designing preventive or remedial measures. Sulfur in coal is a problem because sulfur dioxide emitted during coal combustion is a main source of acid rain. The sulfur isotopic evidence shows that sulfur in low-sulfur coal is derived primarily from parent plant materials. Sulfur enrichment in medium- and high-sulfur coals is caused by the sulfate in seawater that flooded the peat swamp during coal formation. The sulfur content of a coal is controlled primarily by the depositional environment of coal seams. Only pyritic sulfur can be removed by physical coal cleaning processes (coal preparation). Sulfur dioxide emission can be reduced using clean coal technologies, such as flue-gas desulfurization, fluidized-bed combustion, and integrated gasification and combined cycle.  相似文献   

11.
An eco-environmental geochemical investigation was carried out in and around the Dexing mining area to determine the concentrations of heavy metals in the surface water, sediments, soils and plants. The main objective of this study is to assess the environmental situation and evaluate the transferring of heavy metals from mining activities into the food chain. Some samples of water, sediment, topsoil and plant were collected along the Lean River in the Dexing mining area. The total concentrations of Cu, Pb, Zn, Cd, and As were determined by AAS, and Hg was analyzed by cold-vapor AAS. Some indices such as ‘contamination degree‘ , ‘geoaccumulation index‘ , and ‘biological absorption coefficient‘ were used to assess eco-environmental quality. The investigation indicated a highly localized distribution pattern closely associated with the two pollution sources along the Le‘an River bank: one is strong acidity and a large amount of Cu in the drainage from the Dexing Cu mining area; and the other is the high concentrations of Pb and Zn in the effluents released from many smelters and mining, processing and extracting activities in the riparian zone. Results from the investigated localities indicated, at least in part, that some problems associated with environmental quality deterioration should be solved in the future.  相似文献   

12.
This article prognosticates the hydrocarbon generation potential of core samples from fields A, B, C and D in Niger delta, Nigeria. The objectives of this study are to characterize the quality of these core samples by organic geochemical analyses. A total of ten core samples collected from fields A, B, C and D in Niger delta were analyzed using total organic carbon (TOC) content analysis, rock-eval pyrolysis technique. The analytical results of the stud- ied core samples reveal that they have generally high total organic carbon contents (TOC), suggesting that conditions in the Niger delta favour organic matter production and preservation. There is a variation in the kerogen types and this may be attributed to the relative stratigraphic positions of the core samples within the Niger delta. The rock-eval results indicate that the samples from fields C and D contain predominantly Type II kerogen with a capacity to gen- erate oil and gas and hence have good generative potential. The samples from fields A and B contain mainly Type III kerogen and are gas-prone with moderate generative potential.  相似文献   

13.
Sulfur is one of the havardous elements in coal The concentrations of sulfur are relatively high in coal.The major forms of sulfur in coal are pyritic,organic and sulfate.Pyritic and organic sulfur generally account for the bulk of sulfur in coal.Elemental sulfur also occurs in coal,but only in trace to minor amounts.When coals are burned,leached and washed,sulfur will be released in the form of sulfide and H2S,which then reach with O2,water and other substances to change into vitriol,and in some places it may form acid rain.And they will impact water environment,acidify the soil and do great harm to plants and human health.In this paper,on the basis of the data from the Yanzhou mining district,the distribution and concentrations of sulfur are analyzed and the existing forms of sulfur are studied.The variation of sulfur and its impact on the environments also are described when coal is used.  相似文献   

14.
To promote the rational development and use of clean coal resources in China, data on the regional and age distribution of sulfur, arsenic and other harmful elements in Chinese coal was broadly collected, tested for content, and analyzed. Coal in northwestern China is characterized by low to extremely low levels of sulfur; the coal of the Taiyuan Formation in northern China mainly has high-sulfur content; that of the Shanxi Formation is mainly characterized by low sulfur coal; and the Late Permian coal in southern China has overall higher sulfur content; other regions have low sulfur coal. The average content of harmful trace elements in the bulk of China's coal is similar to the corresponding content in the coal of the North America and the rest of the world, whereas the content of various elements (Hg, Sb and Se) is different in magnitude to the corresponding percentage in the crust. The average content of the elements Cr, Se, Co, Be, U, Br in Late Permian coal in S China ranks first in the country whereas the average content of Hg and CI in the coals of Late Carboniferous to Early Permian age in N China are the highest. The average content of Mn in Early and Middle Jurassic coal is higher in NW China. The high content of harmful elements in some coal should cause particular concern both in the development and utilization of coal.  相似文献   

15.
One of the main aims of the coal industry is to improve conditions and increase the safety of the work. The questions of environment also need to be considered. In the complex of science-technological problems the focus is placed on how to reveal spontaneous combustion of coals and siltages. The results of spontaneous combustion of coals and siltages are bereavement of the minerals, promise for failures and accidents, and pollution of the environment. The decision of problem of the prevention is very hard, because the spontaneous combustion of coals is an unforeseeable and poorly studied process. The methods of preventing spontaneous combustion of coals must be established. In the first place, these investigations must start with the study of the structure of these coals. The aim of the present work is to determine the differences in the structure of coals with various susceptibilities to spontaneous combustion .Main methods of studying coals include ultimate and proximate analyses, petrographic analysis, analysis of ashes, X-ray (apparatus "Kristalloflex Siemens" using filtered cuprum radiation), extraction (Dionex ASE 200), gas chromatography-mass spectroscopy (GC-MS) Finnigan MAT GCQ. Proximate, ultimate and petrographic analyses revealed the distinction in the structure of coals with various susceptibilities to self-ignition.  相似文献   

16.
《地球化学》1975,(1):75-82
Method for determining the radical content in dispersed organic matter from coal, asphalt, petroleum and sedimentary rocks by means of ESR is discussed. Factors affecting the results are also considered. The possibility of using radical content as an indicator is suggested for the degree of metamorphism of the dispersed organic matter and for other geologic problems pertaining to sedimentary rocks and deposits.From the variation of relative concentrations of radical in flame coal samples determined after experiments at elevated temperatures and pressures, the maxium temperature to which the flane coal may have been subjected during its evolution and the temperature-pressure limit for the flame coal-fat coal inversion have been predicted.  相似文献   

17.
Total of 23 bench samples were taken from the No. 7 Coal of Iqe Coalfield, Qinghai Province, China, following Chinese Standard Method GB/T 482-2008 (2008). These samples were analyzed by powder X-ray diffraction (XRD), inductively coupled plasma mass spectrometry (ICP-MS) and X-ray fluorescence (XRF). The results indicate that the No. 7 Coal belongs to a low rank (Ro,ran =0.659%) and high-ash coal (40.54%). Compared to common Chinese and world low-rank coals, the Iqe coal contains anomalous concentrations of rare metal elements, rare-scattered (dispersed) elements and rare earth elements. The highest contents of Rb, Cs, Ga and REY reach to 180, 26, 37, and 397 ppm, respectively. Their average contents of these elements are 10.9, 15, 4.8 and 3.5 times higher than those of world coals, respectively. Minerals in the coal include kaolinite, quartz, muscovite, siderite, and traces of rutile, and brookite. Kaolinite could be main host minerals of Rb, Cs, Ga and REY. The anomalous rare element Rb and Cs accumulation in the Iqe coal is related to both organic and inorganic matter. The REY concentrations may be related to circulation of thermal solutions, contained or sorbed by clayey particles, and organic matter as well.  相似文献   

18.
A comprehensive assessment of man-made impact on the environment is much kept behind because of missing unified systems of environmental monitoring. They represent sources of reliable information on the current status of the environment, as well as the absence of approaches to assess the impact of chemical pollution by different anthropogenic sources. Vegetation, being the component of environmental systems, is very sensitive to atmospheric man-made load. However, permissible concentrations of elements in plants, causing deflection in their development are differently estimated in different regions and vegetation species. As to the Baikal region, it is commonly the sanitary state of woods, that is primarily assessed. Coniferous trees, in particular pine, represent the main tree species in the region. In the Olkhon region we investigated the trace element compositions in pine needles to obtain the background contents of toxic metals. This region of the National park lies 300 km away from the industrial sources of pollutants, beyond the zone of wind effect, and has no industry. The research was made on the healthy (green) and dried up (red) pine needles. The elements like Zn, Al, Mn, Fe, Cr, Cu, Co, Ni, Sr, Cd, Pb, Li, Rb, Sb and As were measured by atomic absorption and flame emission photometry. The samples were decomposed in autoclaves with the mixture of nitric acid and hydrogen peroxide. Distinct differences were found in a series of elements contained in the green and dried needles. The red needles are characterized by higher contents of Zn, Al, Cu and low Mn, Fe, Pb with similar contents of other elements.  相似文献   

19.
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   

20.
Stable isotopes, such as C, N, O and S, are successfully used as classical environmental tracers. During the last few years, heavy stable isotopes are getting more and more attention as tracers and proxies in biogeochemical and environmental studies. Multicollector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS) has enabled scientists to obtain high precise isotopic analyses of heavy elements such as Cl, Ca, Fe, Cu, Zn, Hg and Pb. These isotopic systems can be used as important tracers in studying metal contaminants, biomedical processes and pollution of aquatic environments. MC-ICPMS is a powerful technique for the isotopic analysis of most elements, with the exception of light elements such as H, C, N and O and noble gases. The advantage of the ICP source is that it can ionize all elements with very high sensitivity. Various inlet systems can be used to introduce samples into the mass spectrometer, for instance gas chromatography (GC), liquid chromatography (LC), laser ablation, or conventional liquid nebulization. The aerosol is transported by an Ar and/or He gas flow into the ICP source where it is effectively ionized and introduced into the mass analyzer through a differential pumping system. The variable multicollector detector array allows the user to adjust the detector positions along the focal plane of the mass spectrometer so that all isotopes of interest can be measured simultaneously. Molecular interferences as carbides, nitrides, oxides, argides or doubly-charged species can show up in the mass spectrum and interfere with the elemental isotope peaks. High mass resolution is needed to effectively discriminate against these interferences. The ion optics of the Finnigan NEPTUNE is specially designed to meet this requirement and expand the power of isotope ratio measurements even to elements where previously isobaric interferences were the limit.  相似文献   

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