Long-term production scheduling modeling for the open pit mines considering tonnage uncertainty via indicator kriging

The economic consequence of the modern day mine is highly dependent on careful management of cash flows and risk during production. Mine planning is a critical mechanism at all stages in the life of an open pit mines that major element of mine planning is the optimization of long-term production scheduling problem (LTPSP) within operational constraints such as mining slope, grade blending, ore production and mining capacity. The LTPSP at open pit mines studied in recent years is usually based on a deterministic tonnage estimate of block to be excavated and processed over a number of periods. However, models have now been developed to generate mixed integer linear program (MILP) geological estimates that more accurately describe the uncertain geology while often attempts have been made to account in the grade estimates and they do not take in to account in the tonnage estimates. In this paper, we use tonnage uncertainty in a mixed integer linear programming approach. The tonnage uncertainty is calculated from indicator kriging method. We show decision-making can by use this model will find the blocks with the highest probability for the first period, lower probability blocks for the next period that satisfies all operational constraints; therefore, will to cause the mentioned results highest net present value (NPV) in terms of practical. In this paper, traditional and uncertainty-based models are applied to an iron ore deposit. Results showed that the uncertainty-based approach yields more practical schedules than traditional approaches in terms of production targets.