The change follows an independent metallurgical process review by Lycopodium and Orway Mineral Consultants, which found opportunities to enhance project value ahead of a planned definitive feasibility study.

Lycopodium is the lead engineer for the DFS.

The review found a MRC could support an increase in process plant capacity of about 10% to 30 million tonnes per annum.

That would involve annual copper-in-concentrate production of 65,000tpa at steady state, complemented by about 900t of molybdenum.

Previous expected production was 60,000tpa.

Project economics have also changed, with net present value increasing about $600 million to $2 billion.

Expected life-of-mine revenue has increased 8% to $19 billion, while processing costs are slashed by 5% due to the exclusion of the CPF circuit.

All-in sustaining costs decreased 14% to $3.09 per pound of copper produced.

With an internal rate of return of 21%, project payback will be 5 years.

The DFS is scheduled for delivery in 2024's first half.

Caravel managing director and chief executive officer Don Hyma said the results of the review and update had exceeded expectations.

"The increase in copper production stems from relatively minor changes and enhancements to the project flowsheet, in combination with the inclusion of the previously flagged MRC," he said.

"Importantly, we have also used a modest assumed price of US$4/lb (A$5.96) for copper and US$20/lb (A$29.81) for molybdenum with significant scope for upside on these prices."

Hyma said the outcomes of the review would be frozen into the detailed engineering phase.