| Errors inherent in mineral resource estimates are often associated with data abundance and quality, geologic interpretation, the estimation technique, and the mining selectivity applied to the resource model.; In this study the Lower Coleman Orebody, a large tonnage nickel-copper sulfide deposit, was selected to evaluate the performance of various grade estimation techniques throughout the various stages of the exploration/mining life cycle. This was achieved by incrementally removing sample data, in 10-year increments, starting with the exhaustive database of the 1999 model to the database that was available in 1960, with the latter representative of the exploration stage. Parameters assessed include the appropriateness of estimation within a transformed coordinate system, the application of variance correction techniques, and the effect of constrained ore wireframes versus mineral type envelopes.; The findings of the study indicate that although modifying the subtleties in the grade estimation technique parameters may improve a resource estimate, it is the sample data density and geological interpretation that are key. (Abstract shortened by UMI.)... |
