نتایج جستجو برای: middle coal

تعداد نتایج: 186550  

Journal: :MMWR. Morbidity and mortality weekly report 2016
David J Blackley James B Crum Cara N Halldin Eileen Storey A Scott Laney

Coal workers' pneumoconiosis, also known as "black lung disease," is an occupational lung disease caused by overexposure to respirable coal mine dust. Inhaled dust leads to inflammation and fibrosis in the lungs, and coal workers' pneumoconiosis can be a debilitating disease. The Federal Coal Mine Health and Safety Act of 1969 (Coal Act),* amended in 1977, established dust limits for U.S. coal ...

1997

Pulverized Wyoming subbituminous coal was beneficiated by low-pH oil agglomerationat CONSOL to prepare the coal for direct liquefaction. Conventional cleaning is not veryeffective in cleaning this coal; for example, conventional oil agglomeration only givesabout 20% ash rejection. To improve ash rejection, the coal-water slurry was acidifiedto a pH of about 0.5. Oil agglomeratio...

2009

Self-ignited, naturally occurring coal fires and fires resulting from human activities persist for decades in underground coal mines, coal waste piles, and unmined coal beds. These uncontrolled coal fires occur in all coal-bearing parts of the world (Stracher, 2007) and pose multiple threats to the global environment because they emit greenhouse gases—carbon dioxide (CO2), and methane (CH4)—as ...

ژورنال: علوم آب و خاک 2017
جعفریان, زینب, حیدری, قدرت اله, سپهری, زهره, کاویان, عطااله,

Ash and coal produced from fire influence the soil and few studies about these effects are available. For this purpose, this study was performed to investigate the effect of ash and coal on hydrological, physical and chemical properties of soil in Charat rangeland that has a history of fire. Systematic-random sampling was implemented in two plant types Astragalus gossypinus and Artemisia aucher...

شفیعی بافتی, بهنام, شمعانیان, غلامحسین, عمرانی, هادی, یوسفی, مرضیه,

The Ghoznavi coal mine, as an active mine in Golestan Provice, is located about 45km south of Azadshahr. Coal extracted from first (I) and third (Ш) coal layers. XRD and SEM/EDS studies indicate the presence of quartz and clay minerals as major and pyrite (arsenopyrite), gypsum, jarosite (natrojarosite), goethite, hematite, plagioclase, K-feldspar, rutile and corundum as minor minerals. After c...

Journal: :American journal of industrial medicine 2011
Deborah D Landen James T Wassell Linda McWilliams Ami Patel

BACKGROUND Particulate exposure from air pollution increases the risk of ischemic heart disease (IHD) mortality. Although coal miners are highly exposed to coal dust particulate, studies of IHD mortality risk among coal miners have had inconsistent results. Previous studies may have been biased by the healthy worker effect. METHODS We examined the dose-response relationship between cumulative...

2004
Yuanping Cheng Qixiang Yu Hongchun Xia

There are many coal seams in high-gas mining area of China. The permeability is low. The gas extraction from the original coal seam is difficult and the commercial value is little. The conception of the safe high-efficient exploitation of coal and gas is put forward in this article. It changes the conventional exploitation sequence that is from the upper to below. When we exploit coal seams, th...

1998

Pulverized Wyoming subbituminous coal was beneficiated by low-pH oil agglomerationat CONSOL to prepare the coal for direct liquefaction. Conventional cleaning is not veryeffective in cleaning this coal; for example, conventional oil agglomeration only givesabout 20% ash rejection. To improve ash rejection, the coal-water slurry was acidifiedto a pH of about 0.5. Oil agglomeratio...

2012
Francesco Barone-Adesi Robert S Chapman Debra T Silverman Xinghzhou He Wei Hu Roel Vermeulen Bofu Ning Joseph F Fraumeni Nathaniel Rothman Qing Lan

OBJECTIVE To estimate the risk of lung cancer associated with the use of different types of coal for household cooking and heating. SETTING Xuanwei County, Yunnan Province, China. DESIGN Retrospective cohort study (follow-up 1976-96) comparing mortality from lung cancer between lifelong users of "smoky coal" (bituminous) and "smokeless coal" (anthracite). PARTICIPANTS 27,310 individuals u...

M. Karamoozian S.Z. Shafaei Z. Bahri

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...

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