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 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) executed 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 focused on the proposed development of a new 2.4-million-tonne-a-year copper/zinc mining operation at the brownfield project. The study focused on Jorc resources to a depth of 1350 m, down-dip of the historic mining that extracted 46-million tonnes down to about 900 m.

An optimised and updated BFS is currently being finalised and will be published in the third quarter of 2024. This study considers early production from high-grade near-surface Jorc resources at 40 000 t a month while preparing the deeps ore for extraction at 200 000 t a month from the fifth year of operation.

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 with 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.

The mine is fully permitted.

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 undertaking trial mining. Construction of a 40 000 t/y concentrator plant and starter tailings facility is planned for 2025, with first concentrate production targeted for early 2026, market conditions permitting.

Latest Developments.
Funding secured from the Industrial Development Corporation and Triple Flag Precious Metals Corp to advance PCZM totals R1.8-billion. An initial drawdown of R370-million since November 2023 has allowed for the successful completion of a trial mining exercise and the completion of a revised BFS.

The updated 2024 BFS will address perceived challenges associated with the BFS20, including reducing the lead time to production and minimising peak funding, confirming the skills and experience required to undertake underground mining, and optimising the mine dewatering plan. 

Key milestones already achieved in the development of the mine and execution of trial mining include:

• recruiting an experienced site-based management and operating team that is in place.
• establishing a 15 MVA Eskom grid connection.
• trial mining of ore above the -105 m level, above the water level at 265 m, is under way and has proven the early mining assumptions and designs. Development ore is being stockpiled at surface.
• having pumping infrastructure for phased, reduced-rate, early dewatering in place and successfully tested. 
• the construction of the evaporation pond, which is almost complete.
• the plans for 40 000 t-a-month early mining and the Phase 1 concentrator plant being well advanced.
• having planned the deep sulphide deposit (BFS 2020) as an expansion phase, starting from the third year of operations.

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.