A novel model for sustainable production scheduling of an open-pit mining complex considering waste encapsulation

This work presents a novel mixed integer programming model for simultaneous optimisation of ore production and waste dumping schedule for an open-pit mining complex. The model maximises net present value and generates an optimal flow of materials from multiple sources (open pits, stockpiles) to destinations (processing streams, stockpiles, waste dumps) within the supply chain of a mining complex. In addition, the proposed model implements sustainable mining practices as it ensures the responsible disposal of potentially acid forming waste. An application of the new simultaneous and the traditional two-step (or sequential) methods confirms that the proposed method derives higher net present value and reflects a distinct advantage in addressing the acid mine drainage problem through encapsulation of potentially acid forming wastes. In addition, the results reveal that the new model requires less waste haulage work leading to a significant reduction in greenhouse gas emissions.