Justification of Criteria for Selecting Coal Waste Dumps Suitable for Heat Recovery
O. A. Guzeev, A. A. Podrukhin
Institute of Physics of Mining Processes, Donetsk, Russia
Keywords: Coal dump, self-heating, geodynamically active zone, methane, air, selection criteria, heat utilization
Abstract
Some criteria are justified for selecting coal waste dumps suitable for heat recovery as a case-study of solid mine waste accumulated in the Donbas. These criteria involve geodynamics-position of a dump relative to the boundaries of an active geodynamic zone, as well as air dynamics-gas permeability of rocks in this zone and methane concentration in air entering the dump. It is shown that young and medium-age dumps situated within the boundaries of closed unflooded mines can contain mixture of air and gas with an explosive concentration of methane. The model of changing the role of mine methane in generation of the heat field in a self-heating dump is described. The model uses the idea that methane can both reduce the oxidation rate in coal waste and intensify their combustion efficiency. It is proposed to undertake geodynamic and gas dynamic ranking of coal dumps to determine their suitability as heat generators. The justified criteria can be used to develop a heat recovery technology for coal dumps.
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