Name of the Project
Prieska Copper Zinc Mine (PCZM).

Location
Northern Cape, South Africa.

Project Owner/s
Diversified metals explorer and developer Orion Minerals.

Project Description
The Prieska copper mine is located on a significant volcanogenic massive sulphide deposit. The fully permitted mine, which last operated in 1991, has a Joint Ore Reserves Committee- (Jorc-) compliant resource of 31-million tonnes at 1.2% copper and 3.6% zinc.

The 2020 bankable feasibility study (BFS 2020) conducted by Orion confirmed the potential of Prieska to underpin a significant near-term, low-cost, copper/zinc development project, with exceptional opportunities for future growth.

BFS 2020 is based on a 12-year 2.4-million-tonne-a-year underground and openpit mining operation, targeting production of 22 000 t/y copper and 70 000 t/y zinc at globally competitive costs.

An optimised and updated BFS is currently being finalised, which considers an accelerated development strategy from high-grade near-surface Jorc resources that have been accessed and prepared for production during the 2024 trial mining programme, while preparing the Deeps ore for extraction at 200 000 t a month from the fifth year of operations.

Underground mining methods are planned to be used in conjunction with conventional froth-flotation concentration to produce differentiated copper and zinc concentrates for export.

Mechanised ramp development remaining from the previous mining operations allows for early access to underground production mining areas. 

A combination of longhole open stoping, with drift-and-fill mining, supported by cemented backfill, is envisioned.

Peak production is estimated at 23 000 t/y of copper and 88 000 t/y of zinc.

The life-of-mine is expected to be 16 years from current Jorc resources with expectations of extensions of the orebody providing potential for 30% to 50% upside.

Potential Job Creation
About 200 to 300 jobs are expected to be created during the early mining phase and about 800 at full production.

Net Present Value/Internal Rate of Return
The BFS20 study showed a pretax net present value, at an 8% discount rate, of A$779-million, and an internal rate of return of 39%. Payback from first production, which was expected in the thirty-third month was estimated at 2.4 years. 

The current optimised study has focused on the addition of early production from the eighteenth month, which is expected to reduce the peak external funding requirement and also to improve the project’s financial returns.

Capital Expenditure
Market intelligence firm S2 Research, which follow the project and company announcements closely, noted in May 2022 that it expected the revised peak funding requirement for the Prieska project to decrease to R2.25-billion. This was expected to reduce the funding risk of the project.

Planned Start/End Date
The mine is operational and has undertaken trial mining. First concentrate production is targeted for early 2026, market conditions permitting.

Pumping infrastructure for phased, reduced rate, early dewatering is in place and successfully tested and construction of evaporation pond completed.

Latest Developments
The BFS for the Prieska project is on track for completion in the fourth quarter 2024 quarter, with trial mining of the supergene orebody at PCZM successfully completed, providing key inputs for the updated BFS.

As part of the trial mining programme, Orion has completed primary ramp and haulage development and accessed ore over 270 m strike within the +105 Level block and exposed ore up to the 77 m level. Ore sourced from the trial mining will be used for metallurgical optimisation tests and the detailed design of a modular sulphide concentrator plant.

Further, Orion has indicated that phased development is  under way to facilitate early production and generate cash flow, with the potential to reduce peak funding requirements and underpin a staged build-up towards achieving full-scale commercial production.

Key Contracts, Suppliers and Consultants
Fraser McGill Mining & Minerals Advisory; METC Engineering; Gariep Mining and Exploration Services; Patterson and Cooke; Power Plant Electrical Technologies; Prysm; Professional Cost Consultants; Z Star Mineral Resource Consultants; P2 Mining a division of Newrak (trial underground mining contract); FlowCentric; EcoElementum; Sasol ENAEX; Solar Mining Services; Aquaplex, Partzone; Quebar; and UMS Shaft Sinkers.

Contact Details for Project Information
Orion Minerals, tel +27 11 880 3159 or email info@orionminerals.com.au.