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
