نتایج جستجو برای: coal mines
تعداد نتایج: 37421 فیلتر نتایج به سال:
Coal-mine owners are required to measure miner exposures to respirable dust so that compliance with Federal health regulations can be monitored. This study analyzes the problem of possible underreporting of dust exposures. Using two statistical approaches, data for three mining occupations in 54 large underground coal mines during 1976-1978 are examined for evidence of underreporting. First, re...
Saline waters from underground coal mines in Poland often contain natural radioactive isotopes, mainly 226Ra from the uranium decay series and 228Ra from the thorium series. More than 70% of the total amount of radium remains underground as radioactive deposits due to spontaneous co-precipitation or water treatment technologies, but several tens of MBq of 226Ra and even higher activity of 228Ra...
This paper describes the analysis of fatal accidents of Indian coal mines from April 1989 to March 1998. It is found that Indian mines have considerably higher accident and fatality rates compared to those in USA and South Africa, respectively. While open cast mines are generally known to be safer than underground mines, the Indian open cast mines are shown to be at least as hazardous to the wo...
Investigations into the cause and control of the production of sulfuric acid in effluents of coal mines, and the effects of such effluents upon streams were begun in 1946.1 Working and abandoned mines of Western Pennsylvania alone contribute an estimated million tons of sulfuric acid per year to the drainage area of the Ohio River. A field survey of mine drainage and receiving streams was inaug...
Prior research has suggeste d that the source of respirable silica dust in underground coal mines is typically the immediate top or bottom lithology adjacent to the mined seam, not mineral matter bound within the mined coal bed. Geochemical analyses were applied in an effort to identify the specific source rock of respirable quartz dust in coal mines. The analyses also demonstrate the compositi...
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