Maximising the economic performance of your comminution circuit through cut-off optimization

Abstract

ABSTRACT The comminution function is just one in a long chain of value-adding functions that begins with ore in the ground and ends with the sale of metal, concentrate or some other product. The creation of an economic model for comminution is complicated by the fact that it is difficult to identify the exact amount of value added by comminution, and further complicated by the fact that changes in comminution impact on a range of other associated functions such as ore-waste discrimination (cut-offs), mine scheduling and downstream processing. The authors argue that in order for comminution to be modelled effectively, it must be incorporated into a framework which includes many other related functions. In this way, a change in the comminution circuit can be evaluated after taking into account its effect on other related activities. This paper also presents a significant innovation which allows the simultaneous optimization of milling time and processing cut-offs, with the objective of maximising NPV.