Automatic generation of feasible mining pushbacks for open pit strategic planning

The design of pushbacks in an open pit mine has a significant impact on the mine's profitability. Automatic generation of practical pushbacks is a highly desirable feature, but current automatic solutions fail to sufficiently account for complex geometric requirements of pushbacks, including slopes, phase bench and bottom width, smoothness, and continuity. In this paper, we present a tool to fill this gap. Our proposed algorithm is based on modification of sets of blocks obtained by parametric optimization of the pit using a maximum flow method. A set of geometric operators is developed to modify the sets to present a feasible geometry for mining. The geometric operators are essentially derived from mathematical morphological tools. Case studies show that the proposed method generates practical pushback designs that meet all geometric constraints. The algorithm can be used to create a solution for medium-size pits in minutes. This significantly improves the efficiency of designing pushbacks for open pit mines.