A mining investment is a risky business because of uncertainties that exist in the reserve evaluation and economical analysis. The main uncertainties are involved in the amount of overburden and reserve, ore grade, capital and operating costs, recovery, dilution, commodity prices, gross revenue and profit/loss, also in economical analysis, determining if the feasibility of orebody utilizes the cut-off grade technique. This technique assumes that operation cost and commodity price remain constant although they may vary. The modern approach...