Application of simultaneous stochastic optimization with geometallurgical decisions at a copper–gold mining complex

ABSTRACT Simultaneous stochastic optimization of mining complexes aims to optimize its different components in a single optimization model under grade, geometallurgical and material type uncertainty. The single optimization model capitalizes on synergies between the different components and the quantified variability and uncertainty of the materials mined, to better meet production targets while maximizing the net present value (NPV) of a mining complex. Integrating uncertainty and decisions about geometallurgical aspects of materials in the optimization model assists in achieving higher and more stable throughput with comminution circuits. This paper introduces an approach to integrate uncertainty and decisions about two non-additive geometallurgical properties, semi-autogenous power index and bond work index in the simultaneous stochastic optimization model. An application of the proposed approach at a large copper–gold mining complex indicates higher chances of meeting the different production targets, substantial increase in metal production and a 19.3% increase in NPV compared to the conventional plan.