SLIM - sustainable low impact mining
Quarries, and occasionally open pit mines, are increasingly being established near to communities and existing blasting sites are being encroached by expanding communities. Thus the unavoidable side effects of rock blasting, such as ground vibrations, air blast, fly-rock, are an issue of increasing importance. In Europe, ground vibrations from blasting are subject to legal restrictions and norms. The operation permit of a blasting site demands that those limits are not exceeded.
Current mitigation strategies include: decreasing the size of the charges that detonate using smaller drill-holes, using decked charge or fewer blast-holes in a round. Such actions are most probably associated with higher costs an poorer productivity. One could also change the initiation direction and delay times in the round while avoiding the other cost driving actions. Most work of the latter type is based either on trial-and-error, or on very simplified models that don't take the actual site specific factors into account, such as the viscoelastic subsurface properties and the topography.
SLIM's breakthrough consists of using state-of-the-art seismic techniques of waveform modeling that includes a realistic subsurface description in combination with electronic delay detonators to minimize blast vibrations at selected sensitive targets.
This will provide a systematic way of adapting the geometry and initiation pattern of a blasting round so that the vibration amplitudes at critical frequencies at sensitive targets are minimized. This will allow the blasting site to reach a more economic compromise with legitimate environmental claims, e.g. by operating closer to sensitive targets and thereby allowing mining of otherwise uneconomic parts of deposits.
This project has received funding from the European Union’s Horizon 2020 research and innovation programme 2014-2018 under grant agreement No 730294.