Abstract
In the A154N Kimberlite pipe at the Diavik Diamond Mine, Blasthole Open Stopes are opened and established using drop raise methods. Lifts are blasted in the raise up to a cap; the cap and slot are then blasted to full stope width and height. After backfilling, the subsequent stope must then be re-slotted next to the backfill. In order to reduce the cost and cycle time to drill and blast a raise and slot for each stope, foam raises have been used. Large foam blocks were lowered into an open stope before backfilling commenced. After backfilling was complete, the foam was blasted creating the necessary void for the next stope in the stoping line. This method can be less expensive and faster than re-slotting with a drop raise and slot in certain circumstances. The method was tested in various stope geometries and was only successful in certain stope layouts. Further to this, the use of plastic pipe for blasting has yielded increased ore recovery.
This novel method has been used elsewhere at a limited number of sites, however little information is available on their implementation. This paper outlines the various trials undertaken at Diavik and the circumstances in which the method was both successful and unsuccessful.