Mining Dilution: Variable Versus Fixed Factor

Abstract

Mining dilution affects the economy of mining projects in many ways. For example, dilution increases costs and can cause reconciliation issues that are common in mining operations. A common approach to estimating mining dilution is to apply a fixed factor to the entire block model. The fixed dilution factor is usually driven by assumptions that are made based on experience and general knowledge. Mining dilution occurs in contact area of ore and waste, but not in the centre of the orebody. Because fixed dilution factor ignores the changes of values within an orebody, the designs driven by such studies can become suboptimal. The methodology described in this paper assures dilution factors are calculated on a block-size scale and honor the variability of values within the orebody. Applying a variable dilution factor enhances the accuracy of mining studies and subsequent economic evaluations. This will be demonstrated using a case study.