PRODUCTION at one of Australia’s biggest copper mines is set for a solid rise.
The OZ Minerals-owned Carrapateena already has the potential to produce 65,000t of copper and 67,000oz of gold a year over its expected 20-year lifetime.
The iron-oxide–copper–gold (IOCG) underground mine, located about 160km north of Port Augusta in South Australia, produced its first concentrate at the end of December 2019, targeting 4.25Mtpa throughput rates by end 2020 and 4.7-5Mpta from 2023.
OZ Minerals chief executive Andrew Cole said the company remained confident in the long-term demand for copper from traditional sources as well as from the rapidly expanding focus on carbon reduction.
“The company is planning to continue its investment in growing Carrapateena,” he said.
“2019 was a year of major progress for OZ Minerals,” Mr Cole said.
“We will test and optimise the plant in the first half of 2020, leading to gradual throughput and recovery increases which will drive progressively higher output in the second half before turning cash positive in 2021.”
The December quarter saw 26,845t of copper produced in the mine, an increase of 23,100t from the previous quarter.
This met the copper guidance for the fifth year in a row.
Low cost energy solutions
In mid-2019, OZ Minerals announced plans to trial a hybrid power station at Carrapateena.
The collaboration project between OZ Minerals and SunSHIFT plans to work with partners to test, trial and pilot new technologies from industry, research institutions, and governments, among others.
Electricity will be generated from a 250 kW solar PV system and 10kW wind turbine generator, and stored in a 250 kW lithium ion battery, integrated with a diesel power plant, demand management technologies and electric light vehicle charging station.
The Carrapateena hybrid electrical project can offer other mines an opportunity to evaluate the commercial value of a wind and solar PV asset at a remote mine site.
Investors may be encouraged by the low cost solution to power generation which could go towards improve the feasibility of mines in the development phase.
NSW-based company SunSHIFT is focussed on exploring developing similar energy solutions for remote mining operations and have experience in installing and operating renewable energy plants at other mining projects.
Production
OZ Minerals acquired the Carrapateena mine from Rudy Gomez and other shareholders in May 2011 after the copper-gold deposit was discovered by Gomez in 2005.
The operation is made up of four exploration licences spread across a 1,070sqkm area in central South Australia.
It is located on Pernatty Station with its supporting infrastructure located within Oakden Hills Station.
Carrapateena geology
The project is an underground sub-level cave operation with an estimated mine life of 20 years.
The copper-gold deposit, hosted in brecciated granite complex, sits under about 500m of un-mineralised rock cover.
The vertical shaped pipe is being mined using sub-level caving with the ore processed to produce copper concentrate.
With a 300m diameter and a vertical depth of 1,000m, the cylindrical-shaped Carrapateena deposit is located within the eastern margin of the Gawler Craton and hosted by the Carrapateena Breccia Complex (CBC), which is overlain by 470m of Stuart Shelf sediments.
The mineralisation at Carrapateena is dominated by coarse-grained disseminated chalcopyrite with common occurrences of sulphide vein-fill and blebs.
The Carrapateena mine is estimated to contain 79Mt of probable ore reserves grading at 1.8pc copper, 0.7g/t of gold and 8.5g/t of silver.
A block caving method involving two 500m-high lifts will be employed at the underground copper and gold mine for ore extraction.
The block cave mine is accessed through two declines, including a main access and a production access decline.
The underground mining project includes two block caves (lifts), a ventilation system delivering 1200m³ of air per second to the mine, access roads, the processing plant and site amenities.
The mine is accessible from the Stuart Highway via a 50km-long access road.
Water supplies for the mining, ore processing and other site activities are supplied from a purposely developed bore field.
Community support
The local community has given strong support to the project from its inception.
A Native Title Mining Agreement is in place with the Kokatha Aboriginal Corporation and is underpinned by a partnering agreement also known as ‘Nganampa palyanku kanyintjaku’, which translates to ‘keeping the future good for all of us’.
