Methodology to include the comminution specific energy into open-pit strategy mine planning using global optimization

Abstract

Strategic Mine Planning demands an accurate knowledge of the mineral deposit, being very important the use of block models supported by Geometallurgy. Currently, the methodology used considers the mine planning divided into parts (ultimate open pit, pushbacks, scheduling). Global optimization can guarantee the optimal solution once all steps are solved together. In the present study the database Marvin was used and the geometallurgical variable comminution specific energy was included. In the first scenario, called GeoMet1, a ramp-up was included in the first three years. In the GeoMet2, different maximum movement ranges were defined, as well as the implementation of ore stockpiles and their subsequent rehandling. Gains of 9.66% in NPV and 5.18% in ore production were found for GeoMet2. The second scenario presented ore production adhering to the programmed, in addition to greater stability in the stripping ratio. In addition, GeoMet2 was more efficient in controlling the comminution specific energy. Therefore, the implementation of mass movement limitations allied to the use of stockpiles favored the optimization of the mine scheduling results. It was possible to verify the importance of including the variable comminution specific energy in the block model, to provide more realistic and reliable results.