Short-term production scheduling in open pit mining consists of defining the extraction sequence and process allocation of mineralized material over time-scales of either months, weeks or days. An effective short-term production schedule will ensure compliance with the production targets and restrictions imposed by the long-term plan. The method proposed herein outlines a new approach to simultaneously optimize the short-term production sequence with the mobile equipment allocation plan while incorporating both material type, grade and equipment performance uncertainty. A new simulation methodology is introduced to generate more realistic equipment performance scenarios, as well as a new concept of including ramp positions in the formulation to facilitate minable extraction patterns. This short-term model is benchmarked against the conventional design at one of the largest copper mines in the world, and the results show improved production target compliance by delivering more consistent material quantity and quality to each processing destination, and a physical extraction sequence that has a greater likelihood of being executed according to plan in the face of equipment performance and truck cycle time uncertainty.
Published November 2017 , 23 pages