Control of Ore Loss and Dilution at AngloGold Ashanti, Iduapriem Mine using Blast Movement Monitoring System

Abstract

Blast Movement Monitoring (BMM) system is a new method of determining material movement during blasting in order to minimise ore loss, dilution and sometimes misclassification. The BMM system was introduced at AngloGold Ashanti Iduapriem (AAIL) Mine in the first quarter of 2013 as a result of reconciliation challenges at the start of operation at the Ajopa Pit in the first quarter of 2012. Since the introduction, there has been improvement in reconciliation, but the cost implication became worth assessing because of dwindling gold price. The main objective of this paper, therefore, is to assess the benefits or otherwise of BMM system on blast induced movement at Iduapriem Mine. The study comprises data collection on BMM system at AAIL and its analysis, as well as cost and benefit analysis. From the BMM data analysis, it was observed that, the bottom flitch of the blasted material moved more than the top flitch in the horizontal direction while the reverse was the case for the vertical movement. The cost-benefit analysis from four shots analysed revealed that there was a benefit of $753 835 which translates into 650% return on investment. Thus, the use of the BMM system has positive financial impact on Iduapriem Mine. Continuous use of the system as a grade control practice has, therefore, been recommended for the Mine, especially with shots containing ore. Furthermore, a dedicated team for this task has been recommended to enhance efficiency. Finally, high precision GPS has been suggested to be added to the detector instrument to make surveying of pre-blast and post-blast BMM points easier and faster. Keywords : Blast Movement Monitoring System, Ore Loss, Dilution, Misclassification, Reconciliation