نتایج جستجو برای: coal
تعداد نتایج: 31950 فیلتر نتایج به سال:
OBJECTIVE To evaluate the component of coal responsible for coal workers' pneumoconiosis (CWP). METHODS A literature search of PubMED was conducted to address studies that have evaluated the risk of CWP based on the components of coal. RESULTS The risk of CWP (CWP) depends on the concentration and duration of exposure to coal dust. Epidemiology studies have shown inverse links between CWP a...
Mercury emissions from coal-fired electric generating utilities are a major uncontrolled source of mercury in the environment. This mercury may be contributing to serious health problems in segments of our society. The USGS is compiling information on mercury in coal that may be useful in developing strategies for reducing mercury emissions from coal use. The USGS coal-quality database contains...
Coal is a highly variable fuel, which ranges from high heating-value anthracite through various forms of bituminous coal to intermediates in coal formation, viz. lignite and peat. Each of these types of fuel can contain different levels of moisture, non-combustible inorganic material (ash), sulfur, and sometimes significant levels of other impurities, e.g. arsenic, fluorine, lead and mercury. R...
The correlation between local mechanical (elasto-plastic) and structural (composition) properties of coal presents significant fundamental and practical interest for coal processing and for the development of rheological models of coal to coke transformations. Here, we explore the relationship between the local structural, chemical composition, and mechanical properties of coal using a combinat...
Coal ash is the main waste from power plant. It is estimated that the consumption of the coal for power plant will increase to 240 million tons each year and the coal ash wastes will produce more than 2 million tons per year. Although the utilization of coal fly ash can be reached 74.1%, large amount of coal fly ash and bottom ash still cannot be utilized. The purpose of this research is to dev...
China is the biggest country of coal production and coal consumption in the world (IEA). In 1998, China produced 1250 Mt of raw coal, accounting for 27.5% of total coal production in the world, and holding 71.9% of primary energy in China (SSB). Coal provides 77% of the energy for power generation, 65% of chemical raw material, and more than 50% of commercial civilian energy. The coal industry ...
background : in china, over 80% of all work-related deaths in the mining industry occur in coal mines and human factors constitute 85% of the direct causes of coal mine accidents, which indicates that significant shortcomings cur-rently exist in the safety behavior management of chinese coal mine workers. we aimed to verify the impact of human psychological behavior in coal mine accidents syste...
This paper presents a solution for the detection and control of coal loads that is more accurate and convenient than those currently used. To date, no research has addressed the use of a grinding medium as the controlled parameter. To improve the accuracy of the coal load detection based on the kinetic energy of balls in a tubular ball mill, a Discrete Element Method (DEM) model for ball kinema...
investigations were carried out on coal tailings by conventional cell and column flotation techniques. tests were conducted to assess processing coal tailings of alborz markazi coal washing plant in iran by column flotation. the effects of reagent type/dosage were investigated with conventional flotation and their results were used in the performance of column flotation. also the effects of the...
Coal is a principal fossil fuel driving economic and social development, and increases in global coal shipments have paralleled expansion of the industry. To identify the potential harm associated with chronic marine coal contamination, three taxa abundant in tropical marine ecosystems (the coral Acropora tenuis, the reef fish Acanthochromis polyacanthus and the seagrass Halodule uninervis) wer...
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