Assessing Uncertainty in Recovery Functions: A Practical Approach

Abstract

Recovery functions provide one of the most important tools in the mining industry for summarizing mineral inventory information of a deposit as a function of cut-off grades. They are also used in several stages of the deposit evaluation, including mine planning, financial decision making and management. Recovery functions are commonly obtained from block grade estimates or by mean of change of support techniques. However, these practices do not allow for an assessment of the underlying uncertainty associated with them. This limitation can be overcome by generating multiple conditional simulations of the deposit from which the recovery functions are computed. However, this approach is time consuming and may not be feasible for deposits modeled with a large number of blocks. In this paper, a technique is proposed for simulating recovery functions and assessing the corresponding uncertainty without recourse to conditional simulation. Its application in a number of deposits has shown that if the sole purpose is to assess the uncertainty in the recovery functions then the technique can be used to eliminate the necessity of carrying out multiple conditional simulations.