Simulation of truck haulage system: a case study

Abstract

Gounkoto mine is a mining company located in Mali and operates an open pit. It uses either free dig or conventional drill, blast, load and haul method. The mine has two (2) shovels (Liebherr 9350 and Liebherr 9250) and twenty-six (26) trucks (Cat 777F rear dump, Cat 777D rear dump and HD7805 Komatsu). Gounkoto mine is facing a problem of over trucking in the loading face and the dumping sites. This research was done to determine the required number of trucks needed for the monthly production target and the optimal number of trucks for the mine to eliminate or minimize the over-trucking. For the achievement of these objectives, the shovel-truck activities were studied using time and motion studies. The data were then analysed statistically and used as input data for the Arena® simulation software for the development of models for the mine. The result of the simulation model showed that the current system can be run with 24 trucks to deliver the monthly target. The optimum number of trucks is twenty-nine (29) trucks, because above 29 trucks the change in the production is insignificant (1.48%). Further analysis was done with the dispatching rules as minimize shovel waiting time and minimize truck waiting time resulted in an increase in the current monthly production. If the dispatching rules are applied, 22 trucks will then be required to achieve the production target