Name of the Project
Carrapateena block cave expansion.

Location
The project is located in South Australia’s highly prospective Gawler Craton.

Project Owner/s
OZ Minerals.

Project Description
The Carrapateena project, currently in construction, will mine an 84-million-tonne inventory using the sublevel caving method.

First sublevel cave production is scheduled for the fourth quarter of 2019, followed by ramp-up over an 18-month period to produce 4.25-million tonnes a year.

The sublevel cave will produce an average of 65 000 t/y of copper and 67 000 oz/y of gold over a 20-year mine life.

A scoping study on the Carrapteena block cave expansion has determined that replacing the lower half of the sublevel cave with a block cave and expanding the throughput rate from 4.25-million tonnes a year to between 10- and 12-million tonnes a year from 2026 can create significantly more value than the sublevel cave. The block cave would be supported by expanded surface infrastructure.

Two options have been identified for increasing the current sublevel cave processing plant capacity to either a new parallel processing plant or upgrading the current sublevel cave processing plant.

Within the plant upgrade option, there are two suboptions – a parallel milling circuit or a tertiary crushing circuit.

The study has recommended the plant upgrade with a tertiary crushing circuit as the most likely path for increasing processing plant capacity; however, both primary options can feasibly meet the requirements of the scoping study.

A block cave expansion of the lower portion of the current Carrapateena sublevel cave has the potential to increase average life-of-mine copper production from 65 000 t/y to between 105 000 t/y and 125 000 t/y from 2026.

The project will unlock possible future value accretive options for the Carrapateena life-of-province plan.

Potential Job Creation
Not stated.

All-in Sustaining Costs/All-in Costs
Not stated.

Net Present Value/Internal Rate of Return
Not stated.

Capital Expenditure
Preproduction capital is estimated at between $1-billion to $1.3-billion, in addition to the A$916-million cost of the current Carrapateena development.

Planned Start/End Date
Not stated.

Latest Developments
The Carrapateena copper/gold mine has reached nameplate mill throughput rates, with stable operational periods at 500 t/h and more than 90% runtime achieved for a 24-hour period.

Oz Minerals has also said that flotation recovery for several shifts have also exceeded 90%, with concentrate grades of more than 40% copper.

CEO Andrew Cole has noted that while the mine produced its first concentrate in December last year, the minerals processing plant was subject to further work by the construction crew to complete the final commissioning tasks during January and much of February.

The processing plant will continue to be tested and optimised through the first half of 2020 and, along with the mine production ramp-up, will drive progressively higher throughput and concentrate produced during the second half of the year.

As the ramp-up progresses, production for 2020 is expected to range between 20 000 t and 25 000 t of copper and between 35 000 oz and 40 000 oz of gold.

Key Contracts and Suppliers
None stated.

Contact Details for Project Information
OZ Minerals, tel +61 8 8229 6600 or email info@ozminerals.com.