Justification of Open Pit Mining Technology for Flat Coal Strata Processing in Relation to the Stratigraphic Positioning Rate

The article describes a problem of considering the coal strata bedding for the scheming of dragline mining technology for open pits developing flat seams. For three flat coal seams strata processing the main criterion defining the choice of technology of their processing is the stratigraphic positioning rate for the middle coal seam. It is the ratio of the upper and lower interbeds height. Based on the fact that it is possible to process coal strata with two methods—the consequent and the simultaneous ones, it is necessary to define the limits of the effective using of these methods. The consequent method (with the shift of upper overburden cut) provides alternating explosion and excavation of the upper, and later—the lower interbeds with transferring the rock into internal dump. The simultaneous method is based on synchronous blasting and transfer of the upper and the lower interbeds. It is important that this method does not provide overburden cut shift. As the result the detailed analysis of the methods of excavation and re-excavation of rock array under dragline mining method allows optimizing technical and economic indicators of three flat strata processing. The research results are presented on the example of Southern Kuzbass (Kemerovo region, Russia) coal deposits being developed by several open pit mines.