QUALIFICATION OF THE CONFIDENCE LEVEL TO PLANNED STOPES USING THE RISK INDEX (RI)

Abstract

The mining stopes are planned considering the geometries of the mineralized body and the development of the drives, following the mine scheduling. After design, it is done the quantification of mass and grade for each stope with the purpose of evaluating if they are over the cut off grade. However, the values are extracted from the estimated block model and it is important to know the confidence level for those values of mass and grade. To solve this issue, an evaluation was made of some available methods, including Slope of Regression (SOR), Kriging Efficiency (KE), Data Geometry Index (DGI) and Risk Index (RI). Checking the results obtained, based on the best research scenarios of the Pilar mine, we chose to use the Risk Index as a method to qualify the confidence level of the planned mining stopes.