The company has achieved a rate of 4.25 million tonnes a year consistently during the month of November, despite a three-day COVID-19 lockdown being implemented across the state.

OZ Minerals completed the ramp up within 12 months, which was six months earlier than planned.

The company was already on track to achieving the new production rate during the September quarter as the rate was maintained for 22 days.

OZ Minerals managing director and chief executive Andrew Cole credited the milestone to all involved with the Carrapateena ramp up project.

“While the mill achieved nameplate capacity in March 2020, the mine production ramp up has continued throughout the year and has been completed some six months earlier than originally anticipated,” Cole said.

“The cave continues to perform well, caving through the Upper Whyalla zone on November 27, with the cave now approximately 260 metres from the surface.

“Importantly, this cave growth milestone further de-risks the establishment of the cave.”

The Carrapateena block cave expansion will significantly increase the mine life to at least 20 years.

Once complete, OZ Minerals will use a sub-level caving mining process, blasting the deposit in 25 metre sections and collecting the ore from loaders.

This will then be crushed and loaded onto the conveyor belt and transported to the surface.

The expansion is expected to lift Carrapateena’s throughput rate to 12 million tonnes a year from 2023.

During the September quarter, OZ Minerals produced 7063 tonnes of copper and 13,760 ounces of gold at Carrapateena, putting its year to date production at 16,728 tonnes of copper and 33,224 ounces of gold.