Optimizing pit shells in the presence of geologic uncertainty with a heuristic algorithm

Transactions of the Society for Mining, Metallurgy, and Exploration , 2018, Vol. 344, No. 1, pp. 38-47

Acorn, T.; Deutsch, C.V.

DOI: https://doi.org/10.19150/trans.8747

Understanding and managing risk is of increasing concern for the mining industry. Although methods exist to model geologic uncertainty based on stochastic modeling techniques and multiple realizations, there are few approaches to manage this geologic uncertainty in pit optimization. Block values can be penalized if the block uncertainty is high, but the goal here is to consider the reserve risk within the pit. This paper presents an approach for pit optimization that considers all realizations simultaneously with a heuristic pit optimizer. The heuristic algorithm maximizes value and also penalizes reserve risk. The inclusion of multiple realizations provides access to the risk or uncertainty in the total pit value. Considering this information permits an active risk management approach that can manage the uncertainty in the reserves within the entire pit.