Determination of optimal cutoff grade policy for an copper mine in Turkey

摘要

The objective of the planning process for an open pit is usually to find optimum annual schedules that will give the highest Net Present Value (NPV) while various production,blending,sequencing and pit slope constraints. In the paper,the cutoff grade policy,one of the most important parameters which affects the strategic mine planning process,was studied considering the all constraints mentioned above for a copper mine in Turkey. This paper describes the process to determine the cutoff grade strategy used in a mining operation based on Lane's algorithm using an optimisation factor which is iteratively calculated for every production year which dynamically adjusts the remaining reserves and thus the total life of the mine to maximise the project NPV. The introduced algorithm is an adaptation from Lane's algorithm that incorporates an iterative routine used to calculate the optimisation factor embedded in the cutoff grade equation. The authors have observed an improvement of the total NPV using the general reduced gradient (GRG) approach.