OZ Minerals has approved an A$600m ($436m) investment for the construction of hoisting shaft at the Prominent Hill copper-gold mine in South Australia.
The expansion project is expected to extend the mine life by six years to 2036 at 6 million tonnes per annum (Mtpa).
Currently, Prominent Hill is producing 4.5Mtpa from an underground mine. The production is expected to increase to between 4.5 and 5Mtpa from 2022 through a trucking operation.
The mine commenced operations in 2009 as an open pit. It was converted to an underground-only in 2018.
According to OZ Minerals, the Wira shaft investment will increase annual copper production rates by nearly 23%.
The company is expected to begin work on sinking the Wira shaft in the first quarter of 2022, with completion scheduled for 2024.
OZ Minerals said that the hoisting shaft will enable access to Mineral Resource outside the current trucking mine plan.
The shaft is expected to come online in 2025 at around the same time when the full depletion of the stockpiled ore from the original open pit is anticipated to take place.
OZ Minerals chief executive officer Andrew Cole said: “Prominent Hill is a quality orebody and remains open at depth. The reliable performance of the operation and its consistent Resource to Reserve conversion rate were all influential in the decision.
“The shaft expansion creates an exciting new future for Prominent Hill with extended mine life and production rates enabling investment in lower emissions and other OZ Minerals environmental and workforce aspirations.”
Prominent Hill is an iron oxide copper gold silver (IOCG) deposit located in the Gawler Craton, which covers approximately 600,000km2 of South Australia.
Apart from Prominent Hill, the Gawler Craton hosts Olympic Dam, Carrapateena, and other smaller and sub-economic copper-gold deposits.
In February this year, OZ Minerals sanctioned the AUD1.25bn ($960m) block cave expansion at its Carrapateena copper-gold mine.
The expansion project is expected to see block cave 1 beginning operations by 2026 and block cave 2 by 2038.
