Solutions to reduce blast-induced ore loss and dilution at the Ahafo openpit gold mine in Ghana

Transactions of the Society for Mining, Metallurgy, and Exploration , 2012, Vol. 332, No. 1, pp. 389-395

Rogers, W.; Kanchibotla, S.S.; Tordoir, A.; Ako, S.; Engmann, E.; Bisiaux, B.

Blast-induced rock mass displacement can have a significant impact on ore loss and dilution. The mischaracterization of the grade boundaries both prior to, as well as a result of, blasting can lead to significant financial losses due to ore loss and dilution. Ore dilution occurs when waste material is miscategorized as ore and sent for processing or stockpiling, diluting the run-of-mine head grade and recovery. Ore loss takes place when valuable mineral is miscategorized as waste and sent to the waste dumps, thus never being processed and recovered. Extensive research has been conducted at the University of Queensland over the last fifteen years to understand the impact of blast movement on ore loss and dilution. Recent outcomes of this research have led to the development of innovative tools and techniques to measure and model blast movement. These techniques have been implemented at the Ahafo gold mine in Ghana to understand blast movement dynamics and to implement solutions to reduce blast-induced ore loss and dilution. These solutions are validated through controlled trials and have been incorporated into site standard operating procedures.