Multiple Seed Waveform Vibration Model of blasts Established at Mont-Wright Mine

The Mont-Wright mine is Canada's largest open-pit iron ore mine with multiple open pits in operation. It is operated by ArcelorMittal Mining Canada in the northeast of the province of Quebec, near the town of Fermont. Fragmentation of rocks with explosives generates vibrations and gas expansion that damage intact rocks, affect existing crack networks, reduce the shear strength of discontinuities and the quality of the rock mass of the highwalls. The efficiency of its blasting operations is challenged by the need to optimize production and manage the risk of mine slope instability caused by vibrations from successive blasts. This paper presents a Multiple Seed Waveform (MSW) vibration model that was established at the mine for this purpose. Near-field signature hole blast vibration monitoring was conducted in multiple areas to establish site characterization as input to the blast vibration modeling at the highwalls of the site. The vibration attenuation laws were established and the effects of different blasthole diameters, shifting frequencies and presplit design were evaluated. Based on the results obtained from the near-field blast vibration monitoring, the calibrated MSW vibration model was used to select blast design parameters to control blast vibration while maximizing productivity of blasts at Mont-Wright mine.