Risk analysis — An aid in selecting an underground mining method

It is very rare in the underground hard rock environment to find a deposit that is ideally suited to a single mining method. During the pre-feasibility stage, a number of conceptual mine designs are generally evaluated to see which offers the best method of extraction for the deposit. By assigning a probability of failure to each component of the mining cycle a measure of the risk for each method can be determined. One mining method may provide the highest NPV when it is performing well, however, there may be a higher risk of a major failure impacting on the performance of that method, e.g. the failure of a mass blast of a crown or rib pillar. This paper will present a flow-chart approach to the use of risk analysis for determining the likely production rates of different mining methods.