Analysis of resource/reserve reporting stages by economic and geostatistical methods

Mine planning and production consist of uncertain processes. Minimizing the effects of uncertain parameters is extremely important in examining the economic dimension of resource/reserve conversions, which is also at the center of this study. Grade uncertainty, which is one of the first important uncertainties encountered in a mineral deposit, was handled in a metallic chrome deposit in this study, and simulations were applied gradually, and accordingly, the economic evaluation over the Net Present Values that the resource can generate with Direct Block Scheduling. Uncertainties have been evaluated by using Sequential Gauss simulation in estimation on resource modeling, monte-carlo simulation on selling price and monte-carlo simulation in the ratio of feed/waste grades in metallurgical recovery. According to the block grade used in the study, a metallurgical efficiency difference of 5.08% at a minimum and 3.91% at a maximum occurs in the results obtained by using varying and fixed metallurgical recovery values. These recovery differences directly affect the number of products to be obtained from the process. This study gains importance in the representation of the differences between the net present values for the open-pit as a result of the optimizations, the minimum limit grade values that occur in the production planning, the tonnages and the uncertainty of the optimization parameters (sales price, technical parameters of production, use of fixed and varying recoveries, etc.). Key Words: Stochastic Simulations, Direct Block Scheduling, Optimization, Varying Metallurgical Recovery, UMREK