Underground planning at stillwater mining company

As part of a new expansion effort, Stillwater Mining Company needed a tool for analyzing development and production scenarios in a new area of an unde rground platinum and palladium mine in Stillwater, Montana. We developed a large mixed-integer programming model that takes as input the planned mine layout, projected ore quality, and projected costs for basic mining activit ies, and produces as output a near-optimal schedule of activities that maxi mizes discounted ore revenue over a given planning horizon. We then used th is model to evaluate various planning scenarios and make recommendations ab out development and production in this new area.