Underground stope design using a practical cut-off methodology
A practical cut-off methodology for underground stope design at Olympic Dam is described. The success of value optimisation of a mine plan through the stope design process is dependent on a cut-off methodology that enables the highest margin ore to be captured within stopes that are scheduled early in the mine plan. This applies particularly to complex orebodies where the grade distribution is highly variable and the optimization of cutoff grade and its translation to practical stope design is very challenging. The methodology is applied from concept through to operational-level stope designs. As part of the cut-off methodology, a variable cut-off strategy is described through a process of stope tranching. Cut-off boundaries, described through geological interpretation, are used to provide consistent and robust capture of target tonnes and grade during stope design.