Aghdarband coal mine, located in NE of Iran, with annual coal and waste production capacity of about twenty million and six thousand tons, respectively, causes the increase of the concentration of some heavy metals in the soil and surrounded sediments. This paper deals with geochemical distribution and environmental effects of the heavy metals on the sediments around the mine, using geochemical...

Blending of imported and domestic coal is becoming of increasing importance. Until recently, coal blending in power stations was mainly adopted to reduce the cost of generation and increase the use of indigenous or more readily available coal. Low-grade (high ash) coal can be mixed with higher grade (imported) coal without deterioration in thermal performance of the boiler, thus reducing the co...

Dense medium coal processing technology has been widely used in coal preparation industries in the world since it is the most accurate and efficient coal preparation process to obtain clean coal with a highest possible yield. Separation of coal and impurities using this technology is based on density differences. In literature, a number of mathematical models exist for dense medium cyclones. On...

The purpose of this study is to comparatively evaluate four types of advanced conceptual power plants based on coal. With efficiency, costof-electricity, and emissions as main criteria, the evaluation was made under consistent design conditions and economic assumptions. The plants considered are a supercritical steam power plant (SC 580◦C), an indirectly coal-fired power system (HIPPS), an adva...

The distribution of antimony (Sb) in topsoil and moss (Dicranum angustum) in disturbed and undisturbed areas, as well as coal and gangue, in Ny-Ålesund, Arctic was examined. Results show that the weathering of coal bed could not contribute to the increase of Sb concentrations in topsoil and moss in the study area. The distribution of Sb is partially associated with traffic and historical mining...

Coal ash from power stations has long been used successfully in the cement industry as binders in several Portland formulations. This is not the case for municipal solid waste (MSW) ash as chloride concentrations, ranging from 10 to 200 g kg(-1) dry weight in the bottom and fly ash, respectively, exceed the maximum allowable concentration in most cement mixtures. To reduce chloride content in M...

In this study, an extraction method and environmental scanning electron microscopy (SEM) are employed to reveal the changes in the occurrence mode of fluorine in a coal-fired power plant in Inner Mongolia, China. The different occurrence states of fluorine during coal combustion and emission show that fluorine in coal mainly assumes insoluble inorganic mineral forms. The results illustrate that...

We study the costs of coal-fired electricity in the United States between 1882 and 2006 by decomposing it in terms of the price of coal, transportation costs, energy density, thermal efficiency, plant construction cost, interest rate, and capacity factor. The dominant determinants of costs at present are the price of coal and plant construction cost. The price of coal appears to fluctuate more ...

The purpose of the controller presented is to maintain the proportion of carbon content in the products of the coal washing dense medium cyclone (DMC) at a certain level by optimally manipulating the density of the heavy medium. In practice, the DMC processes are mainly controlled by empirical methods which are process specific and cannot satisfy the industrial requirements today. As a result, ...

A huge amount of coal is always stored in open spaces in coal-fired power plants before combustion. Mercury released from coal by rain or flowing water is an environmental risk and can cause contamination of the soil around the storage area. To better understand mercury pollution and to control mercury emission before combustion, it is necessary to determine the mobility and leaching characteri...