The equipment utilisation versus mining rate trade-off in open pit mining

This paper investigates the potential value adding role that schemes of exploitation' may have as part of the open pit mine planning process. The deployment of loading equipment within the push-back of an open-pit mine ultimately determines the mining rate'. Traditional mine planning processes seek to adopt schemes of exploitation that maximise the utilisation of the loading equipment as this will typically minimise mining cost. This paper argues that this does not always lead to the creation of value. A case-study demonstrates that alternative schemes of exploitation, with higher mining costs and lower shovel productivity can actually generate greater value. The results show an increase in Net Present Value from US$920M to US$966M when a less productive configuration of four shovels is set instead of a configuration of two shovels. A sensitivity analysis is presented to show the economic and technical conditions that can favour this new proposal.