OZ Minerals Limited owns 100% of the Carrapateena copper-gold project located in South Australia.
| Name | Carrapateena project |
| Location | Located in central South Australia on the eastern margin of the Gawler Craton. 130 kilometres from Port Augusta, 100 kilometres south east of BHP Billiton's Olympic Dam operation and 250 kilometres south east of OZ Minerals' Prominent Hill operation. |
| Deposit | Iron Oxide Copper-Gold deposit |
| Status | Advanced exploration |
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 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. A further 8% was owned by various minorities.
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
During the first quarter of 2011, preparatory work commenced on integrating the Carrapateena project into the Company as soon as possible after settlement.
Subsequent to the announcement of the proposed purchase, detailed technical work undertaken by OZ Minerals and its consultants, who have extensive experience in this style of deposit, has allowed an Inferred Resource to be reported (as per the definitions in the current (2004) JORC Code), for the southern part of the Carrapateena deposit.
This is based upon the information provided to the Company by the vendors.
The understanding of the continuity of mineralisation to the north still only supports the reporting of Exploration Results in this area.
The estimated Mineral Resource for the southern portion of the deposit is tabulated below. This Resource is based on data from 33 holes totalling 45,504 metres.
Please see the Carrapateena Resource Statement Explanatory Notes (PDF 325Kb) for more information.
In addition to these Resources, the mineralisation in the north - which is not part of the Inferred Resource - has the potential to host between 25-45Mt of material at around 1 percent copper, 0.4 g/t gold, 140 ppm U3O8 and 4 g/t silver, for between 0.25 Mt to 0.45 Mt of copper, 0.32 Moz to 0.57 Moz of gold, 7.7 to 13.9 Mlb of U3O8 and 3.2Moz to 5.8 Moz of silver (applying a 0.7% Cu cut-off grade). This is based on 26 holes drilled for 26,119 metres. It should be noted that the potential quantity and grade is conceptual in nature. There has been insufficient exploration to define a Mineral Resource in the north and it is therefore uncertain if further exploration will result in the determination of a Mineral Resource in this area.
Table: Summary Inferred Mineral Resource for the southern portion of the Carrapateena deposit.
Drilling and sampling
Seventy nine holes, including wedges, have been drilled by the vendor into the Carrapateena deposit totalling approximately 78,000 metres.
Drill testing the spatial extent of the prospect started with a 200m x 200m grid sequence, with 100m x 100m infill drilling commencing in September 2006. Two infill holes with four additional wedges were drilled to 50m spacing (North-South) in the bornite zone in the south west of the deposit.
In addition to the drilling at the Carrapateena deposit, exploration was initiated over a further seven regional targets in 2007 with two holes drilled into each for a total of 10,186.6 metres.
Several targets remain untested and at least six warrant further testing.
Mining
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.
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. The uranium at Carrapateena grades around 250ppm U3O8 meaning it is higher than at Prominent Hill but lower than at Olympic Dam. Initial acid leach tests indicate uranium recoveries around 75% although further test work is required.
Project plan
One of OZ Minerals' first priority will be establishing an Inferred Mineral Resource for the northern area of the deposit.
Assuming completion of required exploration drilling and mining option studies, a pre-feasibility study would potentially commence in 2012 and would be anticipated to take approximately one year. After this, full feasibility studies would take a further 18 to 24 months. If studies are positive and the project is approved for development, construction of the plant and infrastructure, along with mine development could commence around 2015. Construction and mine development would likely take a further two years.
Related information