DOI https://doi.org/10.36487/ACG_repo/708_16
Cite As:
Marklund, P-I, Sjöberg, J, Ouchterlony, F & Nilsson, N 2007, 'Improved Blasting and Bench Slope Design at the Aitik Mine', in Y Potvin (ed.),
Slope Stability 2007: Proceedings of the 2007 International Symposium on Rock Slope Stability in Open Pit Mining and Civil Engineering, Australian Centre for Geomechanics, Perth, pp. 279-292,
https://doi.org/10.36487/ACG_repo/708_16
Abstract:
The Aitik open pit mine, located in northern Sweden, currently faces a substantial production increase,
which has necessitated a review and update of design guidelines. This work pointed at the possibility of
increasing interramp slope angles a few degrees, which, in turn, requires an improved bench slope design,
most notably blasting techniques. Building upon previous development work, new field trials were conducted
in conjunction with trimming of the footwall slope to increase ore extraction. Different blast designs were
tested and the resulting blast damage was evaluated through measurements and follow-up. These trials
quantified the limits in terms of achievable bench face angles and amount of backbreak. The detrimental
effects of small-scale structures could be controlled through lighter smooth blasting, whereas the impact of
larger, more dominant, structures, prevailed even for very light smooth (for open pit operations) blasting.
For the footwall, presplit blasting in inclined (70°) holes over the full double-bench height, proved to be
suitable in terms of both achievable bench slope geometry, and production concerns. For the hangingwall, a
presplit blast design is used in specific areas to ensure that sufficient ramp width is achieved. The study
reported here has effectively provided limits on the maximum achievable bench slope angles at the Aitik
mine, as well as an increased confidence in the bench face design currently being implemented at the mine.
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292 Slope Stability 2007, Perth, Australia