Underground Mining: Olympic Dam Expansion - Underground Mine Model

Olympic Dam required the expansion of the mine, materials handling systems and plant. A study was commissioned of the entire underground mining operation, from the stopes to the mill stockpiles. The aim of the study was for TSG personnel to determine the capacity of the materials handling system, whilst taking into account all inherent planned and unplanned system down time and system interactions.

The scope of the model incorporated the mine production plan and extended from the blasting and mining operation, movement of ore by LHDs, the underground rail system, underground crushing, to the hoisting of ore to the surface.

Conclusion

The most valuable information gained from the modelling exercise was that the performance of the overall system could not be predicted by traditional engineering methods. Due to the large number of interactions between the mine sub-systems, it was impossible to predict the system performance simply by summing the individual component capacities. By combining all the mine components via their logical interactions, the simulation model showed that the optimisation of each sub-system did not necessarily produce the best return on investment.

The model was also used to determine the most efficient operator shift rotations, calculate the number and capacity of LHDs required, formulate an effective rail operating philosophy and optimise maintenance scheduling.

The study identified potential bottleneck issues with the proposed operation. Alternative operating strategies were developed and tested with the study team, which increased the potential capacity of the operation, above the set target.

The results of this study gave management the confidence to proceed with the expansion project knowing that their production targets would be met.