Truck dispatching in an open pit mine

Abstract

In an open pit mine operated by trucks and shovels, the trucks should be dispatched from the crusher to the shovels in such a way that the productivity of trucks and shovels in maximized while maintaining a rational production plan as well as obtaining target grades and other objectives with small variations at the entrance to the concentrator.

To solve the dispatching problem we present a three step approach. First we select shovel locations with a man-machine interactive system. This step combines operator expertise and linear programming optimisation. In the second step, we establish an optimal strategy (production plan) for a certain period of time by solving a network problem with non-linear costs associated with estimates of trucks' and shovels' waiting times and the quality objectives. The solution gives, for each shovel, the best access paths, the trucks' and shovels' estimated waiting times and an estimate of the number of trucks loaded per unit of time. In the last step we dispatch each truck in real-time by solving an assigment problem, taking into account the next 15 trucks, which are becoming available for dispatching in order to get a series of dispatches which will realize the optimal strategy.