Mine optimization and its application using the Anglo Platinum Mine Optimisation Tool (APMOT)

This paper discusses the optimization of the mine design and scheduling as it is applied at Anglo Platinum and more specifically, the rationale for and use of the Anglo Platinum Mine Optimisation Tool (APMOT), which has been jointly developed between Anglo Platinum and Cyest over the past four years. Mine optimization is an inherently iterative process since all facets of mine design and scheduling are interrelated. It is not possible to change e.g. the level spacing of a mine, without affecting the scheduling, or the stoping efficiencies and number of crews without considering the development requirement. For this reason, changes to design and scheduling are usually tested using a graphic design and scheduling applications such as CADSmine or Mine2 4D. These applications allow detailed design, based on graphical information of reef contours, thickness, grade, and location. This allows an answer with a high degree of certainty about the exact tons and ounces that can be expected from a project or production schedule. Unfortunately this also means that the process can be time consuming, limiting the number of iterations or options that can be considered. Once the schedule has been finalized the production profile is costed and a capital schedule is estimated to allow financial valuation. Changes in economic assumptions around platinum price or escalation can then also affect the project, potentially rendering it unviable due to the capital requirement or the cash flow profile. True optimization therefore needs to encompass the technical design and scheduling as well as the economic valuation of the scheduling outputs. APMOT encompasses all design and scheduling facets from geology, layout, and scheduling to resource levelling and economics in an integrated non-graphical rules-based production scheduling application.