Blast hole drilling innovation to improve productivity

CRCMining is developing a high-pressure water jet system to improve blast hole drilling performance, which may significantly boost penetration rates while slashing costs per metre.

Lou Caruana

Providing significantly faster drilling rates while reducing blast hole drilling costs through the introduction of a step-change technology will directly improve mine profitability whilst adding operational flexibility, CRCMining hard rock and surface mining program leader Dihon Tadic said.

He believes there is significant opportunity for this technology.

“Preliminary test results in several rock types are very encouraging,” he said.

“Clever integration of the water-jet assisted blast hole drilling technology with existing drilling equipment will significantly improve drill performance and reduce total drilling costs.”

CRCMining’s water-jet assisted blast hole drilling system uses a high-pressure water jet incorporated into a tricone drill bit.

The water jet acts to cut a groove in the base of the hole ahead of the mechanical action of the bit, enabling the rock to fracture more easily along the groove.

When the water jet groove is cut near the perimeter of the hole, the drill bit is able to advance more rapidly, with significantly less pull-down pressure.

Research, development and testing using CRCMining’s full-scale laboratory blast hole drill has demonstrated significant performance gains in various rock types.

Drilling rates in hard rock such as granite were improved by 35%. Drilling rates in sandstone were improved by over 100%, with drastically reduced pull-down force. Preliminary modelling indicates that a commercial system may deliver a 20% reduction in $/m drill costs.

“This technology is a potential game-changer for some drilling processes,” Tadic said.

“Single-pass, surface blast hole drilling is the primary target, with the performance benefits offering reduced fleet sizes through productivity improvement. Also, there is added flexibility with hole sizes able to be increased – or smaller rigs utilised – due to the lower pull-down force requirements compared to conventional drilling.”

CRCMining is looking to demonstrate this technology in a mine production environment in collaboration with a suitable OEM partner.