Name of the Project
Prieska copper/zinc project.

Location
Northern Cape, South Africa.

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

Project Description
An updated bankable feasibility study (BFS) has confirmed the potential of Prieska to underpin a significant near-term, low-cost, copper/zinc development project, with exceptional opportunities for future growth.

The updated BFS on the foundation phase of the project proposes the development of a new 2.4-million-tonne-a-year copper/zinc mining operation at the brownfield project.

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

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

The life-of-mine (LoM) has been extended by two years, from 9.7 years to 11.5 years.

Material changes in the updated BFS, compared with the 2019 BFS plan, include:

• reducing the mine dewatering timeline and supplementing the treatment of that water,
• incorporating additional mineral resources into the mining plan that will increase the mine life by two years,
• a more conservative timeline to ramp up to steady-state production,
• prioritising the early mining of high-grade zones in the mining sequencing,
• the adoption of semiautogenous grinding mills in the processing flowsheet,
• an owner-miner operating philosophy for underground mining,
• using an experienced contractor to operate the processing plan, and
• a change in the key operational infrastructure being supplied by third-party financing and in the supply of select key operational infrastructure.

The mining methods for the project remain unchanged, compared with those stated in the 2019 BFS. Tunnel development remaining from the previous mining operations allows for early access to underground production mining areas. A combination of longhole open stoping with fill and drift-and-fill mining methods are planned to be used, supported with paste backfill.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project has a net present value, at an 8% discount rate, of A$779-million, compared with A$574-million in the 2019 BFS, and an internal rate of return of 39%, compared with 38% in the 2019 BFS. Payback from first production is estimated at 2.4 years, a decrease of five months.

Capital Expenditure
Total startup capital, including contingency, has decreased from A$400-million in the 2019 BFS to A$373-million in the updated BFS.

Peak funding requirements increased from A$378-million in the 2019 BFS to A$413-million.

Planned Start/End Date
Orion Minerals is targeting production startup in 2024, market conditions permitting.

Latest Developments
Orion Minerals recorded several significant developments across its business, which the company expects will deliver important outcomes in the second half of the year, in the quarter to March 30, 2022.

An early production assessment for the Prieska project has been fast-tracked, with investigations into phasing the project development to bring forward the first concentrate production and evaluate remnant pillar mining potential expected to be completed by the third quarter.

MD and CEO Errol Smart has said the decision to investigate early production, together with the mining of underground pillars, should enable Orion to produce first concentrate 14 months earlier than originally envisioned in the 2020 BFS.

Resource infill drilling started at the 105 Level supergene resource at Prieska to support potential early production from openpit mining.

A 6 000 m underground diamond drilling programme is under way, targeting remnant pillars at the project, with a mineral resource update expected to be estimated by the third quarter.

Discussions with banks and financiers regarding the financing for the Prieska Deeps project are continuing in parallel with the engineering assessment of the early works opportunities.

Discussions have also been initiated with potential financiers who have expressed interest in funding the early dewatering and production plan.

Key Contracts, Suppliers and Consultants
Companies involved in the BFS included A&B Global Mining; ABS Africa; BPDT & Co; Bluhm Burton Engineering & Ventilation Consultants; Beulah Africa; Cart Investments; DRA Projects South Africa; Earth Science Solutions; Endeavour Financial Limited; Falcon and Hume Attorneys Inc; Fraser McGill Mining & Minerals Advisory; Knight Piésold; METC Engineering; Gariep Mining and Exploration Services; Mets Consulting South Africa; Patterson and Cooke; PCDS Consultants; Power Plant Electrical Technologies; Professional Cost Consultants; Promethium Carbon; Shift Innovations; SRK Consulting; Strategy4Good; The MSA Group; Turnkey Civil (International) Group; VBKom Engineering Consultants; Whittle Consulting; and Z Star Mineral Resource Consultants.

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