Strategic Optimisation of a Vertical Hoisting Shaft in the Callie Underground Mine

Abstract

The Callie underground mine, located in the Tanami Desert in the Northern Territory, includes two parallel declines accessing a large orebody extending some two kilometres below the surface. One of several ideas considered in strategic mine planning is to incorporate a vertical hoisting shaft and an orepass as an alternative to trucking material to the surface along the declines. In this work, we use network optimisation techniques to investigate the feasibility of the proposed system, and to mathematically determine the optimum positions and geometry of the shaft, orepass and surrounding infrastructure. We propose a modelling procedure taking aspects from a mathematical problem, called the Fermat-Weber problem, which asks for a point minimising the sum of weighted distances to a given set of points. We describe the implementation of the procedure into a computer program for solving the problem iteratively, and present results over a range of infrastructure and haulage costs, decline gradients and life-of-mine (LOM) schedules.