Carrapateena project

Key Statistics

OZ Minerals purchased the Carrapateena copper-gold project in 2011. The project is an Iron-Oxide Copper-Gold deposit located in central South Australia.

The Carrapateena deposit was discovered in 2005 by Rudy Gomez of RMG under the South Australian Government's PACE exploration incentive program. Teck acquired a 34% interest later the same year, becoming the manager of the project.

The project comprises four exploration licences covering 1,070 km2 in central South Australia. The project is situated approximately 75 kilometres from the Stuart Highway and is relatively close to the Adelaide to Darwin Railway via which Prominent Hill concentrates are currently transported. Longer term, there are expected to be ongoing synergies with Prominent Hill.

The deposit

The deposit, like Olympic Dam and Prominent Hill, is an Iron Oxide Copper-Gold deposit. It is hosted in a brecciated granite complex and copper is mostly chalcopyrite with a discrete high grade bornite zone. Mineralisation has been intersected over a vertical height of approximately 1,000 metres, the deposit is roughly cylindrical and its top is located 470 metres below surface. The area above the mineralised zone consists of barren, post mineral, sedimentary rock.

Additional detailed information can be found on the Carrapateena geology page.

Mineral Resource

OZ Minerals released an updated Mineral Resource statement in January 2013.

OZ Minerals completed the initial infill exploration drilling program for the Carrapateena deposit in 2012. This has allowed OZ Minerals to better define the Carrapateena Resource. A significant part of the original Inferred Resource and also part of the northern exploration target area has been successfully converted to Indicated status.

As part of this infill exploration drilling campaign, OZ Minerals announced a 43% increase in total Indicated and Inferred Resources at a 0.7% Cu cut-off compared with the 2011 Mineral Resource estimate. This recent drilling provides OZ Minerals with further evidence that the Carrapateena Resource is a superior deposit.  (ASX Release: Carrapateena Resource upgrade, and a significant new regional exploration copper discovery - 21 January 2013)

Below is a table showing a comparison between the 2011 and 2012 Mineral Resource figures.

Carrapateena Mineral Resource - October 2012

¹The cut-off grade of 0.7% Cu is based on information supplied by the vendors and is considered appropriate for likely mining options.
²CuEq refers to copper equivalent and is calculated as Cu + 0.6 * Au. See the Explanatory Notes for further details of the derivation of this formula.

Studies

Work to date by the previous owners has identified the potential for low cost block cave mining. Other bulk mining methods such as inclined and sub level caving have also been investigated, while the potential to commence early production with more selective mining at higher levels of the mine, followed by bulk mining, is another option that will be examined. Further work will be undertaken by OZ Minerals during its pre-feasibility study.

Processing

Relatively little work has been undertaken on processing options given the early nature of the project. Metallurgical tests indicate that production of a copper-gold concentrate via flotation and acid leaching to extract uranium is possible. Concentrate grades of 30-35% copper with recoveries for copper of 85-90% and around 80% for gold have been achieved in early testing.

Current development

OZ Minerals' first priority is to upgrade the southern inferred resource through in-fill drilling to indicated status and to establish an Inferred Mineral Resource for the northern area of the deposit through exploration drilling. Results to date have been very encouraging both laterally and at depth.

In June 2012 the OZ Minerals Board approved the construction of an exploration decline to allow access to the ore body to conduct geotechnical works. This will provide the necessary information to determine the most appropriate mining technique for this deposit.

OZ Minerals has purchased a remanufactured tunnel boring machine to develop the exploration decline at Carrapateena to allow further geotechnical testing of the Carrpateena deposit and accelerate the project. Works on the decline are expected to commence in 2013 and be completed during mid 2015.

Below is an outline of the Carrapateena – conceptual project schedule. 

Related information

• ASX release: Carrapateena Resource upgrade, and a signficant new regional exploration copper discovery - 21 January 2013 (PDF 1Mb)
• ASX release : Acquisition of Carrapateena copper project complete - 9 May 2011
• ASX release: OZ Minerals acquires Carrapateena copper project - 9 March 2011 (PDF 747.9kb)