BEST STARTING POINT and BEST MINING DIRECTION for OPTIMAL PRODUCTION PROGRAM.
Answering the Key Questions – Where to start the exploitation? What is the best method?
Net present value (NPV) is a cash flow to which a discount rate is applied, set according to the risk level or profitability requirement of a project.
The moment in which the optimization is carried out is very important to maximize the value, because of the impact of the discount rate on it.
Regarding maximization of the NPV, some of the key decisions about the exploitation of an open pit deposit are the starting point and the orientation of the mining sequence. This strategic decision ensures a result located close to the limits of the efficiency frontier through a sequence with both better economic and operational performances.
After knowing the best starting point based on the strategic objectives, this exercise will respect several operational restrictions that will reduce the impact of the operational mining design on the VPN obtained from the optimal phases (pit-shells), minimizing the loss of value. (Fig. 2).
Main benefits obtained by applying this methodology consist of a better performance of the production plan, particularly in the improvement of average grades to process plant, which ultimately results in greater metal content production at the initial periods of the plan, ensuring an early return on investment and a project value improvement. (Fig. 3).
In addition, the possibility of analyzing solution surfaces in 3 and 4-dimensional graphics (3D with graph with respect to a fourth variable), built from thousands of scenarios, allows to analyze the robustness of the strategic definitions with the greatest amount of available information, which is always better than making decisions based on a single optimization run.
Cristian J. Poblete
María A. González
Joaquín A. Romero
Daniel L. Fuentes