نتایج جستجو برای: coal mine
تعداد نتایج: 51787 فیلتر نتایج به سال:
Coal mining is one of the most important causes of environmental pollution, as large quantities of coal dust particles are emitted. Colombia-South America has large natural coal reserves and "El Cerrejón" is the world's largest open-cast mine located in the northern department of Guajira. The aim of the present study was to evaluate genotoxic effects in a population exposed to coal residues fro...
Haul truck future TIMES have been hard for the major truck manufacturers with a number of major mining projects on hold, particularly pressurising the ultra-class market where the key contracts are relatively few and far between, compared to lower-capacity classes. The following details developments at Caterpillar and Liebherr, but also reveals for the first time BELAZ’s plans to roll out key m...
This paper studies the unstable mechanisms of the mechanical system that is composed of the stiff hosts (roof and floor) and the coal pillar using catastrophe theory. It is assumed that the roof is an elastic beam and the coal pillar is a strain-softening medium which can be described by the Weibull s distribution theory of strength. It is found that the instability leading to coal bump depends...
OBJECTIVE To investigate if blood Cu++/Zn++ superoxide dismutase, glutathione peroxidase, catalase, and total plasma antioxidant activities could be markers of biological activity resulting from exposure to respirable coal mine dust in active miners, and of pneumoconiosis in retired miners. METHODS Blood samples were randomly obtained from active surface workers (n = 30) and underground miner...
-. This roper discusses in *M tie process undetien to mitigate the effects of any fiture mine subsidence on prison structures proposed above old abandoned underground workings. The site for a proposed prison complex purchased by the State of Indiana was located in west-central Indiana and was undermined by an old abandoned room and pillar mine. The original plan for construcdon cmsisted of one ...
Environmental concerns over increased coal consumption are fully justified by the past history of coal use. Although improved technology has provided some safeguards, increased utilization will require mining practices, emission control technologies, and waste disposal procedures that are not yet fully integrated into the routine use of the coal energy system. The Committee on Health and Evniro...
background: human activities such as mining enhance the radioactivity levels above normal background which can lead to an incremental increase in the radiation risk to the population. materials and methods: 20 tailing enriched soil samples collected around maiganga coal mine, gombe, northeast nigeria were assessed for their 226ra, 232th and 40k contents using hpge gamma-ray detector. results: t...
Biological processes based on oxidation of sulfur compounds by chemolithotrophic microorganisms are emerging as an efficient and eco-friendly technique for removal of sulfur from the coal. In the present article, study was carried out to investigate the potential of biodesulfurization process in removing the sulfur from lignite coal sample collected from a Mongolian coal mine. The batch biodesu...
Coal mining is one of the core industries that contribute to the economic development of a country but deteriorate the environment. Being the primary source of energy, coal has become essential to meet the energy demand of a country. It is excavated by both opencast and underground mining methods and affects the environment, especially hydrological cycle, by discharging huge amounts of mine wat...
This paper reports the mineralogical compositions of super-low-sulfur (Yueliangtian 6-upper (YLT6U)) and high-sulfur (Yueliangtian 6-lower (YLT6L)) coals of the Late Permian No. 6 coal seam from the Yueliangtian coal mine, Guizhou, southwestern China. The mineral assemblages and morphology were detected and observed by X-ray diffractogram (XRD), optical microscopy and field-emission scanning el...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید