How to Exit Conveyor from an Open-Pit Mine: A Theoretical Approach

Nowadays, the giant open-pit mining operation is to be continued in a more remote and difficult part of the ground. Transportation is the most challenging and costly task in such situations. It accounts for more than 50% of total operating and capital outlay. Among the current transportation alternatives, the conveyor is the best from operating cost and sustainable development points of view. The conveyors should be designed in the way that imposes the lowest cost to the project. The exit method of conveyors from the pit is one main design element which significantly influences the conveyor cost. There are a few methods by which the conveyor system can exit from the pit. Dedicated ramp slot (DRS), the existing ramping system (ERS), tunnel and high angle conveyors (HAC) are these alternatives which are not extensively studied in the past. In this paper, a theoretical foundation is developed to analyze the cost of alternative schemes. Besides, the basis is able to determine the break-even points between the alternatives. In the base case, our computational results indicate that the net present cost of DRS is the lowest possible up to 140 m depth, while afterward the HAC has the lowest net present cost.