Orion Minerals (ASX:ORN) completed a definitive feasibility study for the Flat Mines area within the Okiep copper project in South Africa, according to a Friday filing with the Australian bourse.

The study showed a pre-tax net present value potential of AU$114 million and a pre-tax internal rate of return of 23%, the filing said.

The project is expected to produce 6,500 tonnes of copper annually, with a peak output of 9,500 tonnes over a 12-year mine life, the filing added.

Capital expenditure is estimated at AU$128 million, with all-in-sustaining costs of $5,270 per tonne of copper sold.

The project will be developed in two phases, starting with a 50% processing capacity. It is fully permitted, with key approvals in place, per the filing.

The next steps include securing project financing, finalizing implementation plans, and negotiating off-take agreements.