Complex Underground Mega Blast initiated successfully by Electronic Blasting System in urban area
CIM Montreal 2011
Marc Moffette, André Pomerleau,
The mine plan calls for rapid extraction of the 23 Mt. To realize this plan it is necessary to fire very large mass blasts that can be up to 1.8 Mt in size. Good collaboration between mine personnel, consultants, and suppliers is necessary for the success of mega blasting projects.
An electronic blasting technology enables the initiation of these complex blasts. As the mass blast tonnage steadily increased the needs eventually exceeded the standard system capacity and limitations. To address this issue the electronic blasting system (EBS) was customized by the manufacturer to meet the increasing blast size requirements. Additionally, fast and efficient campaign loading techniques were developed to facilitate preparation of these blasts in a short period of time. In March 2010, the customized electronic blasting system was used to successfully initiate a 1.8 Mt mega blast involving 1191 holes, 805,000 kg of bulk emulsion, and 1406 electronic detonators.
To add to the complexity of the large mass blasts, the mine is located in an urban area with not less than 40 houses located within 1 kilometre of the mine site. Pre-blast house surveys, vibration modeling, control of the maximum kilograms of explosives per delay, and a good communication system are all part of the vibration management program. The vibration management program associated with each mega blast event ensures good relations are maintained with the neighbours.