Energy efficient scheduling of open-pit coal mine trucks

Mining companies are increasingly being challenged to improve energy efficiency, as a method of reducing both the cost and environmental impact of their operations. The haulage activity at an open-pit mine represents a large proportion of total energy consumption. In many other industries, state-of-the-art operations research techniques, such as advanced scheduling, have been applied to support energy efficiency improvements. Despite this, only a limited amount of research using these techniques has been conducted, to face the challenge of energy efficiency in mining. This research contributes an original mixed integer linear programming formulation that schedules haulage activity to minimise the truck and shovel energy consumption required to meet production targets. Since solving the model is found to be NP-hard and intractable for exact methods, a constructive algorithm and tabu search solution technique is developed to solve the model quickly enough for practical use. An operating mine in South East Queensland is used as a case study, to verify and validate the proposed model and solution technique using sensitivity and scenario analysis where significant potential for improvement is found. Several opportunities for using the model as a decision support tool are discussed, including examples of how it can be used for short, medium and long-term decision making.