Reducing Drill and Blast Cost through Blast Optimisation – A Case Study

Abstract

This paper studied the current cost trends associated with the drill and blast operations of Golden Star Resources, an open pit gold mine in Ghana, and further developed a suitable, cost-effective drill and blast geometric parameters for the mine. The study was conducted on three operational pits of the mine, namely Blocks A, B and C. The surface mine was challenged with high cost trends in its drilling and blasting operations. The current and two proposed sets of blast geometric parameters for each active pit, for ore and waste zones, were assessed with the Kuz-Ram fragmentation model. The estimated mean fragment size for the proposed blast parameters were within the desired fragment size range (25 – 65 cm) of the mine, and explosive energy was effectively utilised per in-situ material blasted. The estimated total volume of in-situ material blasted using the proposed blast parameters increased by 14.3 to 50.0% for ore zones and 12.5 to 50.0% for waste zones over current blast parameters. The estimated total drill and blast cost savings if the proposed blast parameters were adopted ranged from 5.3 to 12.2% for ore zones and 2.9 to 14.8% for waste zones.

Keywords: Burden, Spacing, Explosives density, Powder Factor, Cost saving