ABSTRACT

This chapter deals with the various methods that can be used to estimate the quantity and grade of mineral resources and ore reserves which are not only used to evaluate the economic viability of prospective mines but are also vital elements in the performance assessments of operational mines. Ore reserves are derivatives of measured and/or indicated resources and are defined as their economically mineable portions, often with the addition of diluting material. Many inappropriate financial results have been reported by mining companies because either reserves and resources were not properly understood by people using the information or the estimates were incorrect. Resources and reserves are quoted as estimates of tonnages and grade and the available methods fall into one of three main categories: classical methods; distance weighted methods; and geostatistical method. Having well-defined ore reserves for the initial years of mining gives investors more confidence that they will at least have their capital returned.