Carrapateena is a copper-gold deposit located in South Australia’s remote and arid Gawler Craton, approximately 160 km north of Port Augusta. Awarded on a fixed price EPC contract, we delivered the 4.5 Mt/y copper concentrator within a 20-month construction period. Capacity throughput was achieved within a 4-week ramp-up period following commissioning.
The Challenge
Carrapateena represents one of the largest copper reserves in Australia. To realize the environmental, social and economic sustainability benefits required of the project, we were challenged to find a better way to extract and process the copper responsibly and economically.
OZ Minerals needed Ausenco to design a 4.5 Mt/y process plant that was safer, smarter, and more economical than the design completed in the pre-feasibility study. They also needed a partner who could manage the commercial risk and deliver the project via EPC contracting.
The Better Way
Drawing on our expertise in mineral processing and following a collaborative approach with the client during an Early Contractor Involvement (ECI) phase, we committed to a fixed price EPC contract. Our solution incorporated those ideas evaluated and agreed upon during the ECI phase.
We responded to the challenge at Carrapateena with an optimised minerals processing plant design and innovative construction methodologies that greatly reduced environmental impact and drove efficient project delivery. We also found better ways to deliver the project, including use of local and internationally sourced bulk commodities; use of preassembled structures, bolted tanks and prefabricated fully equipped modular switch rooms to minimise site labour; and implementation of Advanced Process Control (APC) to optimise overall plant performance and minimise operator intervention.
Our ‘smart’ plant design reduced the number of people required in operations, with consideration to ready access, data gathering and analytics and general operations. The result was reduced bulk commodities (lower capex), less energy to operate, increased safety of both construction and operations and enhanced environmental outcomes.
With a commitment to create shared value and sustainable benefits for the local and broader community we prioritised South Australian goods and services and employed a diverse fly-in-fly-out construction workforce comprised of 30% local South Australian workers. We also worked with the Kokatha People to deliver employment programs that resulted in 11% of the construction labour force being sourced from the local Port Augusta community.
In addition to the design and construction of the process plant, Ausenco delivered non-process infrastructure, TSF lines (11 km from site), a single pumping station with 6 pumps, a water bore field (50 km pipeline), and potable water plant.
The Outcome
Our team successfully delivered the project within a 20-month construction period, commencing in Q2 2018 and wrapping up in Q1, 2020. First concentrate was delivered in December 2019 and the plant was ramped-up to nameplate capacity in under one month following commissioning completion. It continues to achieve above nameplate throughput and recoveries.
Our cost-effective fit-for-purpose design resulted in 30% less power usage over the life of the plant and a 50% reduction in the overall footprint, compared to the Feasibility Study. We improved operability, maintainability and reduced environmental impact overall – all while successfully navigating challenging freight and logistics tasks to a remote site.
