Assessment of the Influence of Powder Factor on Loading Performance in Selected Open-Pit Granite Aggregate Quarries

Abstract

This study highlights the performance analysis of rock fragmentation on mine excavation process efficiency and powder factor, instantaneous dig factor and loading efficiency. The power regression analysis of the relationship between powder factor and loading efficiency, defines the highest loading efficiency at the optimal powder factor ranging from 0.48 to 0.52 kg/m 3 . Loading efficiency with powder factor 0.50 kg/m 3 is 0.469 while loading efficiency with powder factor 0.30 kg/m 3 is 0.253. However, when considering the powder factor of more than 0.80 kg/m 3 , the efficiency dropped to 0.217 due to the generation of excessive fines and the reduction of the bucket fill rates. The R² value of the regression model is 0.995, thus, confirming the high predictive ability of powder factor while measuring the loading efficiency. In comparison to the original parameters, the optimized powder factor selection reduced the cycle times by as much as 22.4% and increased fragmentation consistency, according to the study. This study potentially highlights the need for enhanced blast design, which optimises total excavation costs and maximises mine productivity.