Three-Dimensional Modeling of Air-Borne Dust Cloud Propagation beyond Surface Mine Boundaries during Large-Scale Blasting
V. M. Khazins, V. V. Shuvalov, S. P. Solov’ev
Academician Sadovsky Institute of Geosphere Dynamics, Russian Academy of Sciences, Moscow, Russia
Keywords: Surface mines, large-scale blasts, dust concentration, maximum allowable values, atmospheric boundary layer, aerodynamics, numerical modeling
Abstract
Wind transport of an air-borne dust cloud in the atmospheric boundary layer in the neighborhood area of a surface mine is analyzed by numerical solution of the Navier-Stokes equations in their full form for a compressible liquid and in a subsonic flow approximation. The dust source is a large-scale blast at a total mass of ~ 100 g of TNT at a depth of 250 m in the pitwall rock mass. The calculations take into account a portion of dust raised above ground surface by blasting. The size of the surface areas of air-borne dust concentrations above maximal allowable values is estimated. The relationship of this size and the wind direction-pitwall angle α is analyzed. The maximal distance between the pitwall and the area of dust concentration above MAV is 3 km. The exposure duration at the fixed point on ground surface is independent of the angle α and ranges from a few minutes at a distance of 500 m from the blast center to a dozen minutes at a distance of 3 km.
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