Production Scheduling in Sublevel Caving Method with the Objective of NPV Maximization

Abstract

Production scheduling optimization is one of the main issues that have a significant effect on the mine economics. Production scheduling optimization in underground mines, has received less attention than in surface mines, and it is still a manual process and in most cases, achieving the truly optimal result through manual scheduling is impossible due to the complexity of the scheduling problem. Caving methods compared with other underground mining methods are low-cost methods and have high production rates. Sublevel caving is one of the main underground mining methods for hard rock mining and there are limited studies about its long-term production scheduling. In this paper, an integer linear programming (IP) model with the objective of net present value (NPV) maximization is developed for production scheduling that is suited for sublevel caving method. The model contains acceptable technical and operational constraints. This model is formulated two-dimensionally (2D) and it can optimize production schedule in thin-layer deposits. In this research, MATLAB programming platform was used to capture the IP model framework. The model was applied on a real block model and the maximum NPV is determined. With respect to determining maximum NPV, it is recommended that the mine development should be determined based on the optimal mining sequence.