Aker Wirth’s MTM will bore a network of tunnels in the Chuquicamata mine in preparation for the later mining of rock containing copper. "Previously, tunnels of this type were blasted out of the rock in copper mines", said Ulrich Frenzle, VP Mining & Construction at Aker Wirth. "These will be created mechanically for the first time with the MTM, thus improving tunnelling efficiency and safety in the mine significantly."
The MTM combines the flexibility of a roadheader with the robustness of a tunnel boring machine, Aker Wirth stated. The self-propelled machine excavates rock with four powerful hydraulically actuated arms fitted with disc cutters. The muck is conveyed to the rear of the machine by a loading apron with loading disks and via a chain conveyor where it is loaded. In addition to circular cross sections like those achieved with a TBM, the MTM can also cut rectangular and horseshoe-shaped or semi-rectangular tunnels with a bore diameter of up to 6m. The turning radius of the 40m long MTM4 is only 12m.
"We expect to set new standards in mine development with the MTM," said Frenzle. "Its development fully reflected quantifiable customer benefits and safety issues. When compared to drill and blast, which up until now was the usual method employed in rock of this hardness, the MTM shall be able to tunnel up to 12m a day, thus more than doubling the current performance".
