Maximum present value calculations with digital computers

This paper discusses maximum present value calculations for a mineral property using digital computers. A semi-quantitative mathematical model to optimize operating conditions is considered. The model is based on a modified cash flow analysis. Many variables affect the solution, and their effect upon present value is described. Selected data (mining rate, costs, reserves, metal sales price, and others) for a hypothetical open pit copper mine are used in a set of solutions for present value. The results are discussed in detail. It is concluded that: (1) Digital computer methods are rapid and useful, (2) Changes in the mining rate, average ore grade, metal sales price and others do affect present value, often severely, (3) Compared to a standard, a higher percentage rate of return may be associated with a lower present value, (4) Time dependent changes in costs may severely affect the valuation model, and (5) More work seems warranted for this type of analysis --Abstract, page vii