High-grade core sample from the 61 million mt of copper- gold resources recently reported at Carrapateena. (Photo: OZ Minerals)
OZ Minerals has initiated a scoping study of the potential for mining startup at its Carrapateena underground copper-gold project in South Australia based on extraction of the deposit’s high-grade core. The study was prompted by a new analysis of the core that identified 61 million metric tons (mt) of resources grading 2.9% copper equivalent (2.4% copper, 0.9 g/mt gold, and 11.7 g/mt silver). An earlier prefeasibility study released in August 2014 was based on much larger indicated and inferred resources totaling 800 million mt and grading 0.8% copper and 0.3 g/mt gold.
The proposed high-grade project would mine up to 3 million mt/y using selective underground mining methods, most probably sublevel open stoping, at a development cost estimated at less than A$1 billion. The 2014 prefeasibility study had considered a mining rate of 12.4 million mt/y, with project capital costs estimated at A$2.985 billion.
The Carrapateena copper-gold deposit is located in central South Australia, about 425 km north of Adelaide and 250 km southeast of OZ Minerals’ Prominent Hill mine. Since purchasing the deposit in 2011, the company has undertaken a significant amount of work on how to best develop it. In April, the company committed to evaluating three development options: a value-optimized, stand-alone block cave project, a Gawler Craton strategy linking Carrapateena to the Prominent Hill mine via a 250-km rail line, and a high-grade option. The high-grade option is the object of the current scoping study.