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Hard mining industry in Russia |
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Hard mining industry in Russia Authors: J. Wasiuczkow, A. Gonet, J. Siemek
Hard coal reserves are still considerable in size, therefore despite some of its unfavourable properties, coal will certainly play an important role in the future power policy. Russia belongs to the greatest producers and consumers of primary energy sources. Underground exploitation of coal beds is based on labour-consuming mining works. It has been assessed that in Russia, the extraction of 1 Mg of coal is accompanied by 1.2 Mg metal consumption (all kinds of systems and devices). Other aspects that still need major improvement is the work safety of the miners and environmental protection. Generally, coal has a negative share (ca. 8 to 12%) in the warming up effect. The gangue on surface (constituting about 20 to 25% of the extracted coal mass), old workings, and hydrogeological conditions in the mining areas considerably change the natural landscape. The combustion of 1 Mg of coal is accompanied by an emission of 250 kg mineral particles to the atmosphere and ca. 20 to 25 kg of gas with sulphur content (up to 2% of carbon sulfides). The existing conditions necessitate new, more efficient technologies that would minimize the environmental impact. Borehole techniques and technologies create a good perspective for solving problems encountered by mines. These methods are presently applied for drilling boreholes of different technological destination, and for methane removal. Two scenarios of coalbed methane extraction with the borehole method were elaborated in Russia. In the first of them solid mineral is produced, whereas in the other one - gas fuel. At a preliminary stage of working out economically and technologically feasible solutions, a construction of a coal-gas electric energy generator is considered. It consists of four basic blocks (Fig. 1), ie. - underground coal gasification block; - methane drainage block; - pre-gasification and pre-drainage block; - drilling works block. The comparison of technical-economic design indices of borehole extraction for electric energy generation and the traditional methods shows that the application of the former is expected to increase the utilization level of useful energy encapsulated in coal fuel ca. 3 to 4 times, and also lower the cost of electric energy by 1.5 to 2.2 times.
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2011