Correlation between ore mineralogical composition at different depths and Bond Work Index for the Erdenetiin Ovoo Cu-Mo porphyry deposit, Mongolia

The Erdenetiin Ovoo Cu-Mo porphyry deposit in Mongolia is the largest copper mine corporation in the nation. In this study, we investigate the grinding properties of biotite granodiorite and granodiorite rock alteration relative to variations in mine depth, with a specific focus on their correlation with mineral composition. The Bond Work Index experimental tests are applied to the Cu-Mo porphyry ore from the Erdenet Mining Corporation in Mongolia. The samples used in this study were collected representing 10 composites of 5 different depth levels with an interval of ~90 m within the 1175-725 m sampling elevation. The chemical, surface analytical, and mineralogical characterizations of the two types of biotite granodiorite and granodiorite ores are performed using Inductively Coupled Plasma, X-ray fluorescence, and X-ray diffractometer methods. Results of the chemical analysis indicate that the Cu and Mo percentages of both biotite granodiorite and granodiorite consistently decreased with depth profiling. The X-ray diffractometer data of mineral composition are used in setting up the prediction of the Bond Work Index estimation model. An equation-based approach to the Bond Work Index estimation model demonstrates a strong linear correlation (R²=0.895) with the measured Bond Work Index from experimental tests, with the highest Bond Work Index measured at 19.06 kWh/t. Our experimental results indicate that strong correlations were identified between the major mineral phases and the Bond Work Index values through the integration of ore hardness and mineralogical data.