Deep dive

The Kidd operations copper and zinc mine in Timmins, Ontario, 700 kilometres north of Toronto, is the world’s deepest base-metal mine at 9,880 feet (3,000 metres) below the surface. To get a sense of how deep the mine is, consider Toronto’s CN Tower, at 457 metres the tallest free-standing structure in the western hemisphere. You could stack six and a half of them, one on top of the other, and not quite reach the depth of the Kidd mine.

Profound automation
Mining at such depth creates many challenges, both technical – from seismicity considerations to the atmospheric pressure that increases temperatures, straining ventilation systems – and logistical – getting miners and materials from surface to some of the deepest production levels can take more than an hour.

From the surface, a cage takes groups of the mine’s employees down to a level 4,700 feet (1,430 metres) below the surface. Even deeper at level 88 (that’s 8,800 feet, or 2,680 metres, below the surface) a Sandvik LH514 is working autonomously to maximize production through the mine’s busiest production zone. On another level one of the mine’sfour automated loaders trams into a stope and quickly re-emerges with a load of muck, an area that is currently closed due to seismic restrictions.

A critical eye on utilization and efficiency drove Kidd Operations to solutions like Sandvik  AutoMine. Ryan Roberts, manager of mine operations, acknowledges that the current mining environment is challenging, but he says the goal is the same as always: how to safely and efficiently extract the maximum tonnage out of the ground.

“We have to do all that we can to keep our costs as low as possible, but that shouldn’t really change whether the metal price is high or low,” he says.

Higher utilization rates
Using automated loaders adds complexity to the operation. Areas where automated loaders are tramming need to be closed off to personnel – in some existing mines, such as Kidd Operations, this can mean securing an entire level – and mechanics need to be trained in automated components. Despite these complexities there are clear benefits, Roberts says.

“Our usual shifts were about 10 hours, and we were losing about two hours of that first shift,” he says. “It takes so long to travel underground here, based on depth of mine and travel to and from the workplace.”

Kidd has benefited from the ability to operate its automated Sandvik LH514s for as many as 21 hours of mucking per day, a 30 percent increase in effective production hours compared with its conventional loaders. The mine was even able to reduce its total loader fleet by three units, in part due to the gains it has obtained implementing Sandvik AutoMine Lite.

“With the automation we get a lot more hours on our units,” says Andy Saindon, the mine’s senior engineer production coordinator. “We can muck between shifts, and also during seismic activity after a blast and during gas checks on levels where no personnel are allowed.”

The operators have received the automated units favourably, Saindon says. “They like it because it’s safer, more comfortable than operating within the mine, and they’re away from the hazards, dust and fumes,” he says.

Meeting and defeating challenges
Up on the surface, the Sandvik automated loaders are monitored by people sitting at separate workstations, concentrating on two computer screens each. The screens can show the position of each Sandvik automated loader on a map, the view from the loader as seen by an onboard camera, or even the operation of an underground rock breaker. Multiple levels feed mucked material through ore passes down to transfer levels, and the mine can move its automated loaders between levels and transfers to maximize the efficiency of the production fleet. Transfers are the mine’s production bottleneck and Kidd Operations have worked with Sandvik to reduce cycle time in these crucial areas.

Sullivan ticks off a few of the challenges presented by mining at such a great depth. “We run into huge rock pressure in the structure of the mine, high temperatures, high humidity, ventilation problems – it’s hard to get air that deep, but we need to make sure our employees and our equipment have enough air to operate,” he says. “The Sandvik automated loader allows us to operate in areas of the mine where we usually can’t send employees, such as areas prone to seismic activity following blasting activity or where gas restrictions may limit human access.

“We have to have that muck off the ground – we can’t let it sit there,” he says. “We can then take control of the level, because when we operate in robot mode we own the whole level.
All people and other equipment come off the level, and only the robot operates there.”

Now that Kidd Operations has successfully implemented the Sandvik AutoMine Lite system, the mine is working with Sandvik to continuously improve it. “Improved setup and relocation of our automated loaders and developing isolated areas to ensure auto-only protection of the loaders are the next steps forward in maximizing the loaders’ production,” Sullivan says.