Several test protocols are available for assessing variability andinterpretation of test results, and the input of test results intosimulation programs for projection of mill feed rates for acomminution circuit. The degree of confidence in suchpredictions is of paramount concern to mine owners and theirfinancial supporters, to meet cash flow targets, commercialproduction dates, and avoid risk of failure. Its assessment shouldinvolve resource and mine production geologists, mine planningengineers, as well as a comminution specialist(s), and mill/motordesigners. Critical items are: The number of test samples inrelation to the mineable tonnage of the resource, the projectstage (i.e., conceptual, pre-feasibility, feasibility, or bankableincludingbasic engineering, as well as start-up, commissioning,the payback period, and on-going hardness characterization, e.g.,10 years including potential for expansion). Contiguous sampleintervals are preferred, from which test samples are selected, ineach drill hole which is sited to intersect lithology and alterationzones within cut-off grade limits.
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