This blast required a very high powder factor as we were working with pre-fractured rock in big, blocky chunks. The tighter 8x8 pattern and 2 lbs/yd powder factor helped break up those big chunks instead of just displacing and moving them off the bench. Again, we can let it fly like this when we’re out in the middle of the woods with miles between us and any type of civilization. | McCallum Rock Drilling

Powder Factor calculation for Surface mine Blast Design