Avaliação da produtividade de um sistema de transporte subterrâneo utilizando LHD.

Abstract

The purpose of this research is to estimate the productivity of an underground mine haulage system, using the simulation technique. A hybrid model involving deterrninistic and stochastic simulation has been employed. The model attempts to represent as much as possible the real system. The model has been validated by means of comparison between the simulation results and historical data obtained from Mmeracfio Vale do Jacurici, Ipueira Mine, located in the State of Bahia. The model is based on the advance-clock technique making possible to take into account the mterference between equipaments at the intersection points of the haulage network. The deterrninistic simulation allows the calculation of the travel times, while the stochastic simulation evaluates the efficiency of the haulage system. The computer program takes into account the relevant variables cjccurring in the day-to-day mine operation, such as elapsed time for change of shifts, time off for meals, equipment breakdown, traffic jam at loading and dumping points, waiting time at road crossings, etc. As much as 5,000 simulation runs have been performed in order to ensure a statistical representation of high degree of confidence. The variables considered for estimating the productivity of the system have been the availability of equipment and the existence of rock blocks at the loading points. The variables related to the haulage distance and the number of LHD's per advancing feces have also been considered. The results from the model showed a good agreement with the data from the real system, indicating that the variability between the actual and the simulated system is about 5 percent. The model does not optimize the system in a global way, but it yields good results most of the time.