OZ Minerals has reported the results of a pre-feasibility study of its Carrapateena copper-gold project in central South Australia, about 425 km north of Adelaide and 250 km southeast of the company’s Prominent Hill mining operations. The company stated that sole development of the project is beyond its prudent financial capacity, and it is looking for a partner or partners to participate in development of the project.
The Carrapateena pre-feasibility study supports development of an underground, block-caving operation that would produce an average of 114,000 mt/y of copper and 117,000 oz/y of gold in a high-quality copper-gold concentrate. Mine life based on reserves only would be 24 years at a plant throughput of 12.4 million mt/y. Project capital costs are estimated at A$2.985 billion.
Carrapateena mineralogy is predominantly chalcopyrite with 15% bornite, allowing production of 30% to 35% copper concentrate at 92% recovery from blended feed. Gold is recoverable into the concentrate at 70% recovery. Significant uranium and fluorine rejection from the feed occurs during flotation, with these elements being below typical penalty levels in the concentrate. There is no arsenic.
Operating cash costs, including mining, milling, transport, and administration, are estimated at $0.49/lb of copper, net of byproduct credits.
OZ noted that the Carrapateena project offers a number of opportunities to add value that were not considered in the pre-feasibility study. Large areas of lower-grade mineralization contiguous to the planned mine footprint are available for possible future exploitation. The Khamsin deposit 10 km northwest of Carrapateena and other regional exploration targets also may provide opportunities for expansion of the proposed operation or extension of the mine life.
Mining fleet automation, which is not assumed in the pre-feasibility base case, may offer the opportunity to substantially reduce the operating labor component once the block cave is in steady operation.
OZ Minerals CEO and Managing Director Terry Burgess said, “We are highly encouraged by the results of this pre-feasibility study, which show that the Carrapateena project is viable when based on conservative assumptions, with potential for improved results from a number of options.
“We have reviewed in detail numerous copper-gold projects around the world over the past five years, and there are very few like Carrapateena that offer the potential of multidecade production at low operating costs, with the demonstrated potential for further discoveries nearby, located relatively close to all necessary infrastructure, and in one of the best and safest mining jurisdictions in the world.”