A non-monetary valuation system for open-pit mine design

In open-pit mining, different designs are created, such as optimal ultimate pit limit and production planning. In order to determine the ultimate pit limit, two approaches are generally used based on geological and economic block models. In this paper, according to the long-term trend of metals price and mining costs, some suggestions were made to design the ultimate pit limit using the geological block model. In addition, a grade-based objective function was presented for determining the ultimate pit limit. Then, in order to solve the problem, a heuristic algorithm was developed to simultaneously determine the ultimate pit limit and the sequence of block mining. For a 2D geological block model, the final pit was generated using the proposed algorithm. Furthermore, to validate the generated pit limit, the results of a 3D geological block model were compared with those of the Lerchs-Grossman algorithm. The comparison showed that the two pits corresponded to each other with an accuracy value of 97.7 percent.