Economic effects of ore losses and rock dilution

CIM Bulletin, Vol. 87, No. 978, 1994

J. Elbrond, Ecole Polytechnique, Montreal, Quebec

This paper describes qualitatively the progressive ore losses and rock dilution in a mining project from the geological modelling to and including the concentration. A simple theoretical model of the net present value of a deposit, assuming a log-normal grade frequency function, is used to find the pair of decisions on rate of production and cut-off grade, which maximizes the net present value. Various degrees of ore losses and rock dilution are then applied on this optimum, and the resulting decreasing net present values are calculated, as well as the increasing cost of metal and the increasing metal losses as a function of ore losses and rock dilution.
Keywords: Ore losses, Rock dilution, Modelling.