World’s richest uranium mine to rely on raiseboring for ore production
The Canadian uranium producer Cameco Corporation has invested over CAD 10 million in four raiseboring systems from Atlas Copco in preparation for the start of production, subject to regulatory approval, at the world’s largest high-grade uranium deposit.
The company purchased the first rig, a Robbins 73RM-H, in October, 1998. In March this year, it placed a further order for three 53RH-EX units.
Two of the three new rigs will be used for raiseboring and will be delivered in December this year and in January, 2000. The third, which will be used for boxhole boring, will arrive at the site next February.
The three 53RH-EX rigs were chosen by Cameco because they are versatile, feature a low operating profile, can be used alternatively for raiseboring or boxhole boring and also facilitate the future use of expandable reamers – a technology now being developed by Uniroc, a division of Atlas Copco, the worldwide supplier of state-of-the-art rock drilling equipment.
Says Peter Edmunds, Raiseboring Product Manager – North America: “What makes this job unique is that these four rigs will be the main units producing ore at McArthur River instead of just being used for conventional raiseboring applications such as ventilation, slot, and ore-pass raises.”
Radiation exposure will be controlled during underground operations primarily by feeding the ore directly into a sealed crushing and grinding system – then pumping it to the surface as a mud-like slurry via a vertical piping system.
The high-grade orebody at the mine is between 500 and 600 metres below the surface and mining is complicated by the presence of high pressure water and varying ground conditions. The orebody has to be frozen to control the water flow and raiseborers will face the challenge of working in frozen ground and operating by remote control.
The Robbins 53RH-EX raiseboring rig: The EX stands for extended, as the machine’s capability to accept full-length drill pipes distinguishes it from previous models.