Northern Star internal contractor Northern Star Mining Services (NSMS) has delivered the highest ore recovery in the life of the Kalgoorlie gold operations within two months of installing Minnovare’s drill and blast technology.
The operation achieved 100 additional drill metres per day, resulting in around 3.5 per cent reduction in stope turnover time.
This improvement brings around 5000 additional ounces and $8.4 million additional revenue at the current gold price when rated over a 12-month period.
Minnovare commercial director Mick Beilby said the company worked closely with Northern Star from day one to successfully implement the production optimiser on site.
“As the drillers and engineers continued to use the system, they’ve seen further gains in drilled metres and a continuation of the improved recovery rate,” Beilby said.
The system was installed in April this year as part of a wider technology collaboration agreement between the companies.
NSMS general manager Rob Parsons said the collaboration with Minnovare initially stemmed from the observation that too much time was being spent re-drilling holes.
“That was one of the issues I saw, and we did some hole surveying that showed the percentage of error increased as the dump of the drill holes increased,” Parsons said.
He also noted that drill holes could be two to three degrees different compared to the plan when the output on the inclinometers had shown the same reading.
“It was most visible looking at the final stope pick up – the actual shape didn’t line up with what you had designed. So we were doing extra work just to validate where things really were,” Parsons said.
“In two months we reduced blast-hole deviation at the collar by 75 per cent, increased drilled metres by 17 per cent, with the highest average stope recovery recorded in the life of the operation.”
Beilby said, “We’re really pleased with the initial results from Northern Star. It’s further validation of this new technology and further proof of the impact it can have on the bottom line of any underground drill and blast operation.”