A Comparative Analysis of Rock Fragmentation using Blast Prediction Results

Abstract

This work presents prediction and optimisation of controllable parameters of drilling and blasting currently used at the Fobinso Pit of Perseus Mining Ghana Limited (PMGL). The mine faces challenges with blast particle sizes produced after primary blasting. The presence of boulders requires secondary fragmentation to further reduce the broken materials to the acceptable sizes, thereby increasing the cost of production. The mechanical properties of the rocks were determined using Protodyakonov Rock Strength Index. The drill and blast parameters were estimated using the Konya and Walter (1990), Principle of Proportionality, and Instituto Geologo Minero de España (IGME) model developed in 1987. The Modified Kuz-Ram model was used to predict and analyse the results of blasting based on the parameters such as spacing, burden, drillhole diameter, charge density, charge per hole, charge length, and powder factor. A comparative analysis of the predicted size distributions of the various models using diameters of 65 mm and 110 mm revealed no significant differences between the size fractions. The Principle of Proportionality produced the best technical and economic indices for blasting. Keywords: Fragmentation, Drilling Parameters, Primary Blasting, Models, Secondary Blasting