Komatsu and subsidiary Komatsu Cummins Chile have partnered with Chilean state-owner miner Codelco to trial a new tunnel excavation method for underground hard rock mining using Komatsu’s newly developed Mining Tunnel Boring Machine (TBM).
The trail will begin in 2024 at Codelco’s Chuquicamata mine just outside of Calama in northern Chile, a property that is situated at 2,850 metres (9,350 feet) above sea level.
With the trial, the companies are hoping to fast-track the potential introduction of the technology as demand for underground mining equipment continues to increase along with global demand for mineral resources requiring deeper operations.
“The Mining TBM works by continuously performing a series of processes, such as excavating rock with disc cutters and discharging the chipped rock backwards with belt conveyors, while fortifying the excavated tunnel wall,” Komatsu noted. “Excavation with disc cutters improves tunnel strength and stability by creating a circular tunnel shape with smooth walls with less damage to the excavated tunnel (compared to drilling and blasting method).”
The OEM developed the first TBM for rock excavation in 1963; it was designed for use in civil engineering in Japan. Since then, it has rolled out over 2,300 TBM units, including its Micro Tunneling Machine, to the market.
Using Komatsu’s base in excavation experience, the Mining TBM has been equipped with new technologies enabling adaptability to small curves, reversing and passing intersections in hard rock tunnel excavation. TBMs were previously generally limited to excavating nearly straight tunnels, though the new technology improves the flexibility of the equipment and enables tunnel excavation according to each mine’s unique design.
“To support customers’ needs for increasingly sustainable ways of mining, the new machine runs off electricity, does not require the use of blasting and performs a series of tunnel excavation processes with a single machine, reducing the number of vehicles required overall,” the OEM said.
“The result is a new excavation option that reduces the creation of greenhouse gases and particulate matter emissions for an improved underground environment that requires less ventilation than other methods. At the same time, it significantly increases the productivity of personnel associated with tunnel excavation work compared to conventional methods.”