ECONOMIC SIGNIFICANCE OF SUB-CUTOFF GRADES IN OPEN PITS OPERATING WITH CONCENTRATOR BOTTLENECK

Abstract

Mathematical models are built and a nonlinear algorithm is coded to determine solutions to cutoff grade, sub-cutoff grade and sub-grade stockpile sizes which optimise the open pit mining from an economic point of view. The purpose is to study the theory that it is more reasonable economically for an open pit mine to stockpile its low grade ores and treat them later, especially if the mine has a bottleneck condition at the concentrator.