62
      Sunday
      90 / 64
      Monday
      80 / 62
      Tuesday
      73 / 54

      Drilling U.P.; state of the art drill used at Eagle Mine

      A state of the art drilling venture is scheduled to continue Wednesday at the Rio Tinto Eagle Mine in Northern Marquette County. The company is using a drill that conducts a process called Conventional Raise Boring.

      The drill is one of few in North America. It works from inside the mine up to the surface.

      Six separate pieces of the drill were sitting above ground on Monday. They will soon be combined underground to create a hole 14.5 feet in diameter, according to Rio Tinto construction worker, Peter Muzerall.

      "We bring it underground in individual pieces and put it together underground," said Muzerall.

      The drill bit weighs about 3.5 tons. The equipment will drill about 600 feet to the surface.

      Last month, Rio Tinto created a similar hole for air intake and emergency access. The second hole is for exhaust, according to John Mason, Eagle Mine Superintendent.

      "All of the air will go down to the bottom of the mine and exhaust back through the workings," said Mason.

      With three men working the drill from the surface, the drilling will be conducted around the clock, with the bit returning to the surface in about three weeks. It took seven days for teams to dig a pilot hole that is 15 inches wide. The drill rod goes in that hole, and the bit will be connected to it. The drill is raised about five feet at a time, the length of a rod section, and then that section is removed.

      Mason said this process is a lot safer than methods used before in the mining industry.

      "Before, men had to get underground," he said. "They had to drill and blast and then climb back up underneath it."

      Elsewhere, about 650 feet from the surface and one mile down the tunnel, a construction worker adds a layer of concrete to support the ground in the tunnel to the ore body.

      In another area of the mine, two workers spend their shift on definition drilling. Samples are collected to get a better picture of the ore body. Continued exploration is important to Rio Tinto.

      "Our hopes are that we find more ore underground that's connected to the ore body, and we can continue to mine and increase our mine life," said Dan Blondeau, Rio Tinto community advisor.

      Last week, Rio Tinto said production at the mine is being delayed due to unstable market conditions across the world. Production was scheduled to begin next year. This means a delayed construction process.

      "Even though some of our surface construction is slowing down, we still have a lot of work being done right now," Blondeau said.

      Blondeau said he "doesn't foresee" work at Eagle Mine coming to a complete halt. He said the company will work to minimize the impact to its employees as production is delayed.