Given that a source is located underground and detected by sounds that cannot be completely known or predicted, every stage of the operation from grade changes to product sales exhibits uncertainties. Parameters and constraints used in mining optimizations (sales price, costs, efficiency, etc.) comprise uncertainties. In this research, chrome open-pit resource optimization activities were performed in the province of Adana, Turkey. Metallurgical recovery, which is considered a constant as an optimization parameter in mining software, has been optimized as a variable based on fixed and variable values related to the waste material grade of processing. Based on scenario number 7, which yields the highest net present value in both optimizations, this difference corresponds with an additional $1.4 million, i.e., 7% minimum. When the number of products sold were compared, a difference of 25,977 tons of concentrate production was noted (Optimization II produces less than Optimization I). In summary, concentrated efficiency and economic findings show that using variable metallurgical recovery parameters in NPV estimation improves optimization success by reducing the level of uncertainty.