CRCMining is developing a ground-breaking high-pressure water jet system to improve blasthole drilling performance. This should significantly boost penetration rates while slashing drilling costs per metre. The 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.

Dihon Tadic, CRCMining’s Hard Rock and Surface Mining Program Leader, believes there is significant opportunity for this technology. “Preliminary test results in several rock types are very encouraging,” said Tadic. “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.”

Extensive research, development and testing using CRCMining’s full-scale laboratory blasthole 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 blasthole 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.