Orion Minerals has estimated a total capital expenditure (capex) of A$607m ($382m), including contingencies, for its Prieska Copper Zinc Mine development as per the results of its 2025 Definitive Feasibility Study (DFS).
Located in South Africa’s Northern Cape Province, the project features a two-phase development strategy designed to mitigate risks and accelerate value generation from the underground base metal operation.
The DFS outlines the initial Upper-Level Phase, focusing on near-surface supergene and oxide ores, with production expected to begin 13 months after construction commencement, spanning over 4.3 years.
This phase entails de-watering the main shaft, currently flooded to a depth of 265m, and refurbishing infrastructure to support subsequent deeper mining activities.
Following infrastructure upgrades, the Deeps Phase will begin, projected to operate over 11 years. It will overlap with the last 2.2 years of the Upper-Level Phase, resulting in a combined production timeline of 13.2 years.
Ores from both phases will be processed separately to produce copper concentrates along with gold and silver by-products.
Orion Minerals managing director and CEO Errol Smart said: “The 2025 Definitive Feasibility Study for our flagship Prieska Copper Zinc Mine marks the culmination of a major strategic and technical re-think of the development strategy for this large-scale base metal mine undertaken over the past few years.
“The outstanding results outlined in the DFS-25 confirm the potential to develop a long-life, financially robust mining operation via a two-phase development plan which substantially de-risks the mine development pathway and fast-tracks initial cash flow.”
Key financial outcomes of the DFS include a pre-tax net present value (NPV) of A$797m ($501.4m) and an internal rate of return (IRR) of 31%. The payback period is estimated at 5.8 years from the start of construction, with peak funding needs evaluated at A$578m ($363.6m).
The utilisation of existing infrastructure from previous operations and trial mining is expected to facilitate a quicker transition to production while lowering costs.
According to Orion Minerals, historical data has significantly contributed to assumptions within the DFS, enhancing its accuracy.
The mineral resources at Prieska total 31 million tonnes with average grades of 1.2% copper and 3.6% zinc.
Probable ore reserves are calculated at 15.6 million tonnes with grades of 1.1% copper and 3.1% zinc. The DFS has undergone an independent evaluation by Practara Metals and Mining Advisory, confirming its feasibility.
Moving forward, Orion Minerals’ plans involve securing project financing, implementing detailed strategies, negotiating concentrate offtake agreements, and finalising agreements with service providers for early works.
