AEL Mining Services, a pioneer and leader in development and manufacturing of electronic detonators, recently completed the first phase of the Goldfields South Deep shaft sinking project using its QuickShot electronic detonator system to sink 110 m of the 9.4 m diameter shaft. This followed a contract awarded to AEL by Murray and Roberts in April 2010. “Having seen the outstanding results from the Gautrain project blast – QuickShot electronic detonators were the natural choice to deepen the Goldfields’ South Deep gold mine, some 3,000 m,” says Mark Mocombe, Vice President at Goldfields South Deep.

With foundations 500 mm away from the perimeter ring, a 234 hole and 1.2 m deep round, meticulous care had to be exercised during the blast with cognisance to the winder and compressors, which posed risks and were not to be damaged.

“AEL’s QuickShot electronic detonator system, developed by our sister company, DetNet, was debuted with the Gautrain rapid rail project and achieved maximum advance rates, as well as adherence to environmental restrictions. Blasting was performed without incurring damage to sensitive structures on surface with Peak Particle Velocity (PPV) levels well under the target maximum of 10 mm/s,” explains Carlos Goncalves, Product Manager: AEL Electronics.

He adds that this initiating system coupled with the magnum 29 x 270 cartridge were the winning systems to achieve no fly-rock and foundation damage for the South Deep shaft sinking. “A 1 m trough around 60% of the circumference of the round was created and exposed sidewall at certain places with no muck against it, translating to a presence of definite free face at the time when the perimeter holes initiated. This resulted in minimum back break during hole initiation,” said Goncalves.

Safety is paramount for AEL, and the QuickShot electronic detonator allows charging and connecting to run concurrently with other activities reducing cycle duration. Once the detonator is inserted and charged down the hole, the only remaining risk may be to the protruding cable.

“Given that this was new to us and the crew members, we had no idea how complex the drill and blast design could be. AEL has demonstrated leadership in underground blasting and we are satisfied with the work done so far. The shaft is starting to take shape nicely,” concluded Morcombe.

The second phase of the project requires a further 143 m sinking and has not been awarded yet.