It is not a blast, but this boring machine can change mining
In a dusty brick quarry north of Rome stands a machine so futuristic it looks as if it should be in a Ridley Scott film.
The articulated machine is the first of its kind, a mobile tunnel-boring machine designed and developed by JSE-listed Master Drilling and its Italian contractor Seli Technologies.
Able to bore tunnels 4.5m5.5m in diameter, the machine is unique because it can be lowered into the depths of a mine and assembled from its four component parts. It takes a crew of just three to operate it, and Master Drilling aims to remove one by automating the tunnelsupport function.
It has a 30m turning radius, a fraction of the more than 100m or more of other borers, and it operates on a 12º incline or decline, ideal to sink decline shafts or spiral ramps.
The prototype machine, which Master Drilling hopes to deploy to its first client, has yet to turn its massive cutting head, with last-minute tweaks delaying the start of a technology that could radically change the way mining companies view the development of their mines.
The grinding of rock to create a smooth tunnel to access ore bodies will be quicker and safer than conventional drilling and blasting, with support of the roof and side walls done right behind the cutting head. After a blast, the mine must stop operations to vent noxious gases, while the borer can work around the clock without introducing additional stresses into the rock.
“We want to cut rock, support it and load the cuttings all at the same time. If this machine didn’t do that it would significantly reduce the benefits of this business model,” says Koos Jordaan, an executive director at Master Drilling who heads the new tunnelling division.
It sounds like technology that should sell itself and have mining companies falling over themselves to use it. The interest is there, with companies sending representatives to see the pristine tunnel borer But bluechip miners and others are waiting until it starts to work, digging into the wall of the quarry and proving key selling points punted by Master Drilling.
A South African mining executive liked what he saw but was justifiably cautious. The big questions are about the cost of the machine, its advance speed and whether the back end where the removal of broken rock is done, and the electronics, conveyor belts and dust-suppression gear are, will become a problematic bottleneck.
“We need a solution with a guaranteed outcome,” he said.
“Mining companies would rather take a very good second than a bad first,” was how another executive summed it up.
Master Drilling’s biggest challenge is to overcome the legacy issues of borers used over decades — large, clunky machines designed for civil projects — that were unsuitable for the flexibility requirements and cost structures of mines.
Jordaan says: “If you can advance underground at double the existing rate, you create value by generating early cash flow and opening opportunities with flexibility in management decisions, then surely it’s worthwhile looking at this.”
For a mining company, accessing ore quickly and safely in a manner that allows for the rapid installation of support mechanisms followed by the construction of either conveyors or road surfaces in the access tunnels, is becoming increasingly important as investors are more disinclined to wait a decade for a return.
Mining companies are notoriously reticent to adopt new technology. This is the major hurdle for Master Drilling — finding its first client.
Tunnel boring machines and technology are not new, but the tracked, component configuration that Master Drilling has built and tested with Seli is completely unique, says Fabrizio Antonini, CEO of Seli, a specialist company that has bored more than 1,000 large-diameter tunnels.