A review of cut-off grade policy models for open pit mining operations

In an open pit mining operation, the heterogeneity of the grade-tonnage distribution of the deposit dictates that all available material within the boundaries of an open pit may not be processed. Given this heterogeneity, it is imperative that the valuable (ore) and waste materials are clearly identified. In this context, the cut-off grade defines the quantity of ore and waste, ensuring smooth supply of ore to the processing streams. While, the earliest significant effort towards the development of models for cut-off grade policy dates back to 1960s, a number of contributions on this vital aspect of a mining operation have been made since then. This paper presents a comprehensive overview of the available literature on cut-off grade policy models and suggests possible areas of future research.