Simultaneous optimization of stope layout and production scheduling in sublevel stoping method

Stope layout and production scheduling are two main areas of underground mine planning that have a close relationship with each other such a way that optimization results of each of them have important effects on the other one. Hence, separately optimization of these two areas cannot guarantee the true optimum. Because, in isolated optimization approach often ignores the effects of different planning areas on each other, this is not able to manage issues among different areas. To tackle this problem, simultaneous optimization approaches are developed in recent years which simultaneously optimize the different areas of the mine planning process and lead to more profitable mine plans. In the present research, a mathematical IP model has been developed to simultaneously optimize stope layout and production schedules for sublevel stoping (SLS). Then, the developed model is applied on iron ore operations and obtained results from simultaneous optimization were compared with those of isolated approach. It has been concluded that the simultaneous optimization approach is able to produce the globally optimal scheduling result for the stope layout optimization and scheduling by taking into account all constraints related to both areas. Application of the simultanous optimization method in iron ore operation resulted in a 16 per cent increase in final NPV over the isolated approach.