Global estimates of ore reserves in a beach sand deposit

Several techniques are available for determining the global estimates of or e reserves. However, among these techniques, only the geostatistical techni que provides estimates with the associated estimation variances that allow the determination of meaningful confidence intervals, and, hence, risk-quan tified reserve estimates. Such estimates should provide the basis of planni ng during all the phases of mining projects, including feasibility, mine pl anning and production scheduling. This paper outlines the geostatistical global estimation technique that is commonly applied to massive and thick sedimentary deposits. This is followe d by a step-by-step application of the technique to a beach sand rutile dep osit Based on the data derived from 21 vertical drillholes drilled on a reg ular grid of 30 m by 30 m, the global estimates and the corresponding estim ation variances were determined for the deposit under consideration. A comp arison of the resulting estimates with the corresponding values obtained fr om the combination of kriged block estimates revealed that the two sets of estimates are almost identical, indicating the accuracy of the results.