Pre-conditioning has been used at other block caves to help initiate caves and improve the productivity of the cave draw. A technique to increase the effectiveness of conditioning was trialed. The undercut blast was carried out before the conditioning blasting above it. The area where the conditioning blasting is taking place is undercut, reducing the confinement, and allowing gravity to assist to improve the conditioning effect. This is the first global trial of this Post-Conditioning method. The method is enabled by WebGen™, Orica’s wireless initiation system, as there is no need to have a physical connection with the conditioning holes to be blasted.
Three rings have been fired during the trial, results are currently inconclusive as a reduction in hang ups is unable to be measured presently, the Joint Team expects a significant reduction with an increase in tonnes per shift. Target prediction of the application is a 30% reduction of hang ups with estimated baseline of 30 hang-ups/shift. The intangible benefits include removing people and equipment from working under the seismically active areas of the cave. The loading, stemming, and firing activities were carried out safely and established a new benchmark for the conditioning application.
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