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Samples from outcrops of Jurassic coal seam in Maghara coal mine have been analyzed for their proximates, ultimates, ash constituents and trace elements. Microscopic observations have revealed that the coal is mainly composed of vitrinite, liptinite and inertinite macerals. Vitrain plays an important role in the outbreaks of spontaneous combustion...
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... region is located nearly in the center of North Sinai between longitude 33°10' and 33°40' E, and latitude 30°35' and 30°50' N, covering an area of about 1,300 km 2 (Fig. 1). The re- gion forms about 54 km long and 30 km wide asymmetric anti- cline with a curved axis trending about 55º NE and thus it is par- allel to the Syrian ...
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... assumption of a steady state of individual compartments is important for simplifying the mass equation to a frequently used equation 2. The terms in the equation are fluxes in g.ha -1 .yr -1 re- lated to a surface area of the studied catchment. ∑ i is the net ac- cumulation or depletion of the toxic metal "i" in a small catch- ment (Fig. 10). The mechanism of the mass balance as estimat- ed in the studied catchment (∑ i ) is given herein by the sum of inputs of trace elements minus the sum of their outputs as de- scribed by the mass balance ...
Citations
... Its thickness ranges from 300 to 500 m [37]. Safa Formation includes about eleven seams, only two of them are minable and economic: the upper coal seam (UCS) and the main coal seam (MCS) with thickness of 130-190 cm at Maghara area [38]. Thus, this formation is highly important due to its content of coal bearing seams. ...
The gravity data of Gebel El-Maghara area and its surrounding region in northern Sinai Peninsula, Egypt have been subjected to high precision edge detection filters in order to evaluate the structural and tectonic settings of the study area. Various traditional and modern edge detection filters were tested on synthetic gravity data and then the most successful filters in detection the boundaries of the causative bodies have been used to accomplish the study's objectives. By examining the power spectrum of the gravity data, three gravity maps were generated using low-pass, band-pass and high-pass filters, respectively, representing deep, intermediate and shallow gravity anomalies. The STDR filter and its total horizontal derivative were applied to these gravity maps to image the causative structural features (faults and contacts) and construct structural maps at these different depths. The findings demonstrate that the major trend of faults and contacts at deep depths predominantly aligns along the WNW–ESE direction, while at shallow depths, the main orientation is observed along the NE–SW direction. It is worth noting that the trend of structures at shallow depths demonstrates a good agreement with the structural trends derived from both surface structural map and Landsat images. This trend disparity supports the hypothesis that the formation of the anticlines in the study area is linked to thin-skinned tectonic processes associated with the Syrian Arc system..
... Penelitian pemanfaatan batubara bituminous yang dilakukan oleh Melegy dan Salman [4] pada proses penyerapan ion logam timbal (Pb 2+ ) dan seng (Zn 2+ ) terhadap larutan media air dengan menggunakan batubara bituminous, dalam penelitian tersebut karbon aktif batubara bituminous telah terbukti memiliki kemampuan yang efektif menjadi adsorben untuk menghilangkan Pb (II) dan Zn (II) yang terserap dalam media air. Luas permukaan yang besar yang dimiliki oleh karbon aktif batubara sub-bituminous memiliki kemampuan penyerapan yang tinggi. ...
Adsorpsi merupakan suatu proses penyerapan, salah satu faktor yang mempengaruhi daya adsorpsi adalah luas permukaan (surface area). Pada penelitian ini digunakan adsorben biomassa berupa batubara sub-bituminous, untuk memperbesar luas permukaan dilakukan proses aktivasi. Aktivasi merupakan bagian dalam proses pembuatan adsorben biomassa yang bertujuan untuk memperbesar distribusi dan ukuran Pori serta memperbesar luas permukaan adsorben. Semakin luas permukaan adsorben, maka semakin banyak adsorbat yang dapat diserap, sehingga proses adsorpsi dapat semakin efektif. Semakin kecil ukuran diameter partikel maka semakin luas permukaan adsorben. Aktivasi fisika dan kimia dilakukan untuk melihat terbentuknya pori-pori baru pada karbon aktif yang telah di aktivasi, dengan terbentuknya pori-pori baru maka luas permukaan karbon aktif dapat meningkat setelah dilakukan proses aktivasi fisika kimia. Ukuran partikel hasil karakterisasi menggunakan difraksi sinar-X menunjukkan hasil yang jelas dimana ukuran partikel setelah di aktivasi menurun, aktivasi asam sitrat memberikan nilai sebesar 3,3396 (Å) dan aktivasi asam nitrat sebesar 3,3188 (Å) sedangkan karbon aktif batubara sub- bituminous sebelum di aktivasi sebesar 4,2269 (Å).
... In this study, Egyptian Maghara coal is blended with Egyptian rice straw before being fed to the gasifier. The proximate, ultimate, and sulphunal analyses for the Maghara coal and Egyptian rice straw are summarised in Table 2 (Melegy and Salman, 2009;Stahl and Ramadan, 2007). ...
Rice straw is an agricultural waste that causes an annoying problem in Egypt if it is not well exploited. This study focuses on using this waste in power generation by co-gasification of Egyptian Maghara coal and rice straw blends using entrained flow gasifier technology. Aspen Plus was used to conduct a parametric study for investigation of the effect of changing the inputs to the gasifier on the produced gas composition. Three different input parameters, influencing the performance of the gasifier, including the percentage of coal to rice straw in the blend, the fraction of added water to the blend, and the mass percentage of oxygen with respect to the mass of the blend fed to the gasifier were analysed. Two alternative power production schemes (with and without carbon capturing) have been investigated. The obtained optimum feed conditions are: 40% coal in the feed blend, 20% water concentration in the feed slurry, and 80% oxygen with respect to the dry feed blend to the gasifier. For (10 0000 kg per hour) of the feed blend, the power generated was 270.1 MW in the case of non-carbon capturing, while in the case of carbon capturing, 263.52 MW was generated. Although it produces less power, applying carbon capturing techniques means handling less flue gas and thus using smaller gas turbines and results in more environmentally friendly emissions.
... P<0.001) reflects the origin of Al, which is principally from the alteration of silicates. The processes of oxidation of sulfides and of mineral hydrolysis have given rise to the mobilization of heavy metals, causing abnormally high concentrations of these in AMD[17]. This outcome was especially the case for Zn, for which values of up to 65 mg/l were seen. ...
The Karabash mine area was chosen as the research site for its potential hazardous influence on the environment of Chelyabinsk region. This work presents the results of a geochemical and geophysical characterization of an old tailing containing high contents of sulfide minerals, primarily pyrite (up to 25 wt%), chalcopyrite (3 wt%) and up to 1 wt% of sphalerite and galena. In order to obtain a representative characterization of the study area, geochemical analysis of surface water samples, groundwater composition, bottom sediments analysis and thermodynamic modelling were selected. In all compounds, high levels of trace elements (including Pb, Zn, Cu, Cd, Co, Ni, Fe, Mn) were observed. A thermodynamic modelling study (WATEQ4f) revealed the mobilization of heavy metals mostly through the aqueous and sulfate complexes. Due to the large amounts of dispersed sulfide minerals, the pyrite-rich tailing characterized by an electrically conductive geophysical signature in comparison to the surrounding resistive bedrock. Meteoric water, getting on a tailings surface, gradually penetrates, on the way dissolving secondary minerals and metal salts, being saturated with them. Poorly permeable grounds are capable to accumulate waters, forming underground reservoirs. The distribution of layers with low resitivities suggests that the infiltration of highly mineralized solutions spreads in a direction transverse to the river flow zone. These layers extend to depths of 1–15 m, indicating the penetration of toxicants into the groundwater horizon. The pollution of groundwater confirmed by chemical analysis, according to which the concentrations of Zn, Pb, Ni, Cu and Cd in groundwater samples are two to three orders of magnitude higher than the maximum permissible concentrations (MPC). ERT technique combined with 3D models suggests along with the vertical penetration into groundwater, there is a lateral spread of low resistivity within water-saturated layers, which in this case may be termed an "acid wave".
... The ultimate and proximate analysis of Maghara coal[12] ...
... Chemical analyses play an important role in assessment of the quantity, quality and maturation of hydrocarbon gases (adsorbed and gas in place) present in the coal cleats and buts. Proximate and ultimate analyses are the convention laboratory techniques being used in CBM exploration to trace the percentage of ash, moisture, volatile, fixed carbon, hydrogen, oxygen, nitrogen and sulphur in coals (Melegy and Salman, 2009 ...
Coalbed Methane which offers significant environmental benefits over other fossil fuels has now become an important component of fulfilling energy demands. The production of coalbed methane has become an important industry, providing clean burning fuel. As an estimate the world has 13 trillion metric tons of coal in place. The development cost of CBM is usually lower than the conventional natural gas. The gas produced from coal beds is higher in methane concentration. The geological structure and the properties of coalbed together determine the gas content supplemented by physical and chemical parameters. Ethane and other higher hydrocarbons adsorb strongly than methane, consequently they may not be desorbed at first. Depending upon the maturity, coals have been being characterized as lignite, sub bituminous, bituminous and anthracite. The process of conversion of organic matter to coal generates methane. The amount of methane depends upon the quality and depth-the higher the energy values of coal and deeper the coalbeds-the greater the volume of gas. The reserve estimate and the production forecast differs because of the dual reservoir characteristics-one is the coal matrix, the micropores and the second is open fractures, the macropores-resulting into the reservoir heterogeneity. Geochemical studies like Isotope (biogenic & thermogenic), chromatography (quantity of hydrocarbons) maturation (macerals), deposition environment (bio markers), organic matter type and richness (TOC), proximate and ultimate analysis and mineralogy are used to assess the quality and quantity of hydrocarbons present in the core samples. The objective of this paper is to review the role of geochemistry in CBM exploration with some case studies.
... Al-Maghara coal is a high volatile, lo w rank subbituminous perhydrous coal (wh ich contains more than 6% hydrogen) with a calorific value o f 7422 cal/g [10], the ultimate and proximate analyses of which are given in Table 1. ...
... The ultimate and pro ximate analyses of Almaghara coal[10] ...
Low grade waste heat utilizat ion and new combustion technology are challenging tasks for researchers to achieve these objectives. This paper is concerned with the integration of coal gasification system with a comb ined gas turbine, steam turbine power plant cycles and with ammon ia-water cycle, wh ich is known as Kalina cycle. A l-maghara coal in North Sinai is used as the solid fuel in gasification process.Three cycles configurationsare compared as follows: Scheme (A) with dual pressure Heat recovery boiler with the condenser of steam cycle as the evaporator for Kalina cycle,scheme (B) with heat recovery boiler for both of steam and Kalina cycleand scheme (C), similar to scheme (A), but with a superheating in Kalina cycleto identify the most promising one for implementation. Key parameters of Kalina cycle were the main elements of comparison. Results revealed that scheme (A) has the best performance with regard to the output power, thermal efficiency and specific fuel consumption. Substantially, the integration of Kalina cycle with coal gasification comb ined cycle counterbalances the reduction of the overall efficiency due to the gasification thermal efficiency. Therefore, integration of Kalina cycle in the IC GCC is justified.Furthermo re, part load calculations were made fo r scheme (A) and identified that the integration of Kalina cycle to ICGCC imposed restrictions to Kalina cycle constrains, so that it is more economical to keep such configuration of combined plants at nearly full load conditions.
The energy demand increased dramatically owing to the evolution of industrial and domestic requirements and the associated decrease in oil and gas resources. This study aims to evaluate El-Maghara coal (with about 52 MT reserve) as a potential hydrocarbon source. The collect samples were subjected to petrographic, chemical analyses and Rock–Eval pyrolysis to investigate the detailed characteristics of this coal. Chemically, this coal is high volatile bituminous coal with high H and S content. The high H/C ratio indicates the high extraction yield of coal. The main maceral group in the studied samples is vitrinite (62.8%) followed by liptinite (31.3%) and inertinite (5.8%). The content of liptinite indicates the capability of this coal for petroleum production. Based on Rock–Eval Pyrolysis results and TOC content, the coal has excellent petroleum potential. The hydrogen index (HI) and H/C atomic ratio indicate the II kerogen type (oil prone) of this coal. This coal has Tmax and vitrinite reflectance values around 415.8 °C and 0.37%, respectively, indicating the immature stage of kerogen. The high reactive maceral content (94.2%), oil-yield (65.5%) and conversion from coal to oil (95.4%), indicated that this coal has a hydrocarbon generation potential for oil.
One of the essential factors in underground mining operations is safety during potential mine accidents, like fires, for example. We used Geographical Information System (GIS) for network analysis to identify the best escape routes from different locations inside an underground mine during a fire to a safe place inside or outside the mine. We created an effective evacuation system with a more accurate 2D model based on fire dynamics, the actual dimensions of the mine, and its related elements. We applied our system to the Maghara coal mine to predict the possible fire outbreak scenarios. Our results could be used as a guide to evacuation and rescue plans during harmful events in underground mines, especially fires. Our system is an integrated system that analyses potential fire scenarios and elects the best evacuation plan using GIS technology.
Gabal El-Maghara is located in North Sinai, Egypt. The exposed sedimentary succession is 200 m thick and consists of six formations. Economically, the Safa Formation (160-215 m thick) is the most important rock unit and contains more than 11 coal seams, two of which are minable; namely: The Main Coal Seam (MCS) and the Upper Coal Seam (UCS). The former is ~130 to 190 cm thick and has an estimated coal reserve of about 52 million tons. The Jurassic El-Maghara coal, contains a large mineral assemblage of uranium (betafite, plumbobetafite, kasolite and zippeite) and thorium (thorite and uranothorite) in addition to gold. Zircon, fluorite and barite were also recorded. These minerals are allogeneic (detrital) and, less commonly, authigenic. Allogeneic minerals were inherited from crystalline rocks in Sinai and especially older hydrothermal deposits that were formed at wide ranges of temperature and pressure. On the other hand, some base metals (pyrite, chalcopyrite, galena, nickel, zincite, scheelite and cuprite) in El-Maghara coal were formed authigenically by: (i) precipitation from circulating underground waters; and / or (ii) by the action of marine waters during periods of the post-Jurassic sea transgressions. Gold (0.5 gm/ ton) was originally precipitated from mesothermal and Gold… Mohammed et al. epithermal solutions as a result of changes in physic-chemical conditions and fugacity of oxygen and sulfur. Based on the results of this study, it is recommended to evaluate the importance of El-Maghara coal as a resource of radioactive and some base metals. On the other hand, the coal mines have several negative environmental impacts as they represent a source of significant pollution. This requires taking serious steps to avoid or, at least, reduce this environmental hazard.
