932 resultados para Coal mine accidents


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The catalytic and accelerating effects of three coal-burning additives (CBA) on the burning of graphite were studied with the help of thermogravimetric (TG) analysis. The kinetic study on the catalytic oxidation of the graphite doped with CBA was carried out and the results were presented. The results show that the CBA can change the carbon oxidation/combustion course by catalytic action and change the activation energy, thus improving the combustion efficiency.

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This study seeks both to describe and account for the patterns of industrial relations which have emerged in the UK coal industry since privatisation in 1994. In doing so, it also aims to address some of the wider questions concerning the relationship between ownership and industrial relations. A series of hypotheses are advanced concerning how changes in ownership might affect industrial relations within the industry, and whether such changes would have positive or negative implications for organised labour. A case study approach is utilised to analyse labour relations developments at a number of collieries, and it is shown that the industrial relations strategies adopted by management within the new coal enterprises have had a determining effect upon the patterns of labour relations within the privati sed industry. This study also demonstrates that the emergent pattern of labour relations in the privatised industry is characterised by both continuity and change. However, whilst continuity with the patterns of labour relations established during the final decade of public ownership is shown to have had negative implications for organised labour within the industry, the changes associated with privatisation are demonstrated to have been a more ambivalent force. Change has, in different contexts, had some positive implications for organised labour, but in the majority of cases, the implications for labour have been negative. Overall, therefore, this study concludes that privatisation has had a significant influence upon industrial relations within the coal industry, and that organised labour has been detrimentally affected by these developments.

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A set of 13 US based experts in post-combustion and oxy-fuel combustion CO2 capture systems responded to an extensive questionnaire asking their views on the present status and future expected performance and costs for amine-based, chilled ammonia, and oxy-combustion retrofits of coal-fired power plants. This paper presents the experts' responses for technology maturity, ideal plant characteristics for early adopters, and the extent to which R&D and deployment incentives will impact costs. It also presents the best estimates and 95% confidence limits of the energy penalties associated with amine-based systems. The results show a general consensus that amine-based systems are closer to commercial application, but potential for improving performance and lowering costs is limited; chilled ammonia and oxy-combustion offer greater potential for cost reductions, but not without greater uncertainty regarding scale and technical feasibility. © 2011 Elsevier Ltd.

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An 18 month investigation of the environmental impacts of the Tennessee Valley Authority (TVA) coal ash spill in Kingston, Tennessee combined with leaching experiments on the spilled TVA coal ash have revealed that leachable coal ash contaminants (LCACs), particularly arsenic, selenium, boron, strontium, and barium, have different effects on the quality of impacted environments. While LCACs levels in the downstream river water are relatively low and below the EPA drinking water and ecological thresholds, elevated levels were found in surface water with restricted water exchange and in pore water extracted from the river sediments downstream from the spill. The high concentration of arsenic (up to 2000 μg/L) is associated with some degree of anoxic conditions and predominance of the reduced arsenic species (arsenite) in the pore waters. Laboratory leaching simulations show that the pH and ash/water ratio control the LCACs' abundance and geochemical composition of the impacted water. These results have important implications for the prediction of the fate and migration of LCACs in the environment, particularly for the storage of coal combustion residues (CCRs) in holding ponds and landfills, and any potential CCRs effluents leakage into lakes, rivers, and other aquatic systems.