Master Drilling CEO Danie Pretorius. Picture: FINANCIAL MAIL
Master Drilling CEO Danie Pretorius. Picture: FINANCIAL MAIL

MASTER Drilling will next month unveil a behemoth drilling machine concept that promises to revolutionise the mining sector by sinking shafts up to 2km deep in a fraction of the time it takes to do by hand and with explosives.

The 500-tonne machine, which Master Drilling planned to commission during 2018, would sink a 14m diameter hole into virgin ground accurately enough to be equipped with steel infrastructure to allow for hoisting of men, material and ore, said CEO Danie Pretorius.

Dozens of ore bodies were unable to be exploited because of the time and cost of conventionally sinking a shaft, he said. The new drill could do the work in half or a third of the time.

He declined to say if the process would be cheaper, but pointed out the time value the patented technology would bring to both companies’ bottom line and to shareholders.

The machine would cost more than R500m to develop, build and commission and Master Drilling was considering various funding options, he said.

Technically, the drill will conduct "blind boring", which entails spinning a large reaming disc on the surface, grinding a hole into hard rock and collecting the fragments from the top of the spinning disc.

Master Drilling normally conducts raise boring, which needs a pilot hole sunk into an underground tunnel where the reaming head is attached and pulled to the surface, with the waste collected in the tunnel.

Master Drilling had found a way to steer the descending reamer, Mr Pretorius said.

The diameter of the shaft would allow companies to hoist a mining fleet to the surface in cages for servicing and repairs.

"The quality of work on the surface compared to that in underground workshops is just so much better," he said.

Support for the shaft walls would be precast segments lowered into place, shotcrete or grouting, depending on the cost appetite of the company building the mine, Mr Pretorius said.

Master Drilling had secured a $6.5m contract in the US to sink a blind ventilation shaft with a 3m diameter to the depth of 350m, which would provide the company with valuable lessons, he said.