Blast damage mechanisms at Ekati(TM) Mine

The ability to excavate stable pit slopes in large surface mines is critical to the safety and efficiency of the operation. The stability of the pit wall is greatly influenced by the drilling and blasting techniques in use at the operation. All too often, wall control blasts are designed by simply reducing the kilograms per delay of explosives in the holes near the final wall. The designs are focused around reducing the vibration levels or gas penetration into the final wall, and do not consider the other impacts from blasting which extend well beyond the limits of gas-penetration and vibration.; In the spring of 2000, a joint research project between the BHP Diamonds Inc., the University of Alberta and Western Explosives Limited, was initiated to address the blast damage mechanisms at the Ekati(TM) Diamond Mine. The objective of the project was to gain an increased understanding of the blast damage mechanisms and the impacts to the final wall.; Gas-penetration was not detected behind the production and wall control blasts, however it was detected 5m behind a pre-shear blast.