Optimal Selection and Assignment of Loading Equipment for the Compliance of an Open-Pit Production Plan

Abstract

Open-pit mining is a resource-intensive process since the profitability of the business is strongly related to the magnitude of the tonnage extracted. Therefore, it is necessary to use large equipment to extract and transport material from the mine. The decision of what and how much equipment to buy and where it should be operating, strongly impacts the value of the mining business. Generally, the estimation of the material movements is made using various planning software based on a movement capacity of certain material in tons extracted per day, which does not necessarily represent what happens in the operation. In this paper, a multi-objective optimization model is presented, which aims to determine the optimal shovel-bench allocation for the operation and also show that the equipment allocation obtained can estimate a production plan that fits the reality better than the conventional methodologies. Several operational factors and restrictions are considered including mechanical availability, utilization, space restrictions, and precedence among benches of different pushbacks. Divers experiments were carried and for all cases, and fluctuations were obtained in the tonnages extracted per month that were not predicted in the mine plan with a production defined by a constant flow of tons. The presence of these fluctuations can indicate that a greater number of variables can still be considered within the planning that could allow building of more robust plans to guarantee a reliable operation in terms of production and feed to the plant.