Name of the Project
Tharisa PGMs underground project.

Location
Western limb of the Bushveld Complex, in South Africa’s North West province, where Tharisa Minerals holds a mining right over 5 475 ha near Rustenburg.

Project Owner/s
Tharisa Minerals, a wholly owned subsidiary of Tharisa plc.

Project Description
The project entails the phased transition of the Tharisa mine from openpit to underground mining. The mine is a co-producer of platinum group metals (PGMs) and chrome concentrates 

Openpit mining will continue concurrently with underground development. The openpit operations are expected to be depleted by the 2035 financial year, while the underground transition is intended to unlock more than 60 years of mining potential.

The Apollo and Orion underground complexes form the core of the transition strategy and will be developed sequentially using a phased portal strategy and a bord-and-pillar mining method. Apollo will be developed first, with three access points sequenced to optimise access to reef layers and reduce development risk. Orion will follow and broadly mirror Apollo’s design.

The existing Genesis and Voyager processing plants, supported by the Vulcan ultrafine chrome recovery plant, will provide processing flexibility. Existing processing facilities have a run-of-mine capacity of 5.6-million tonnes a year. The combined Apollo and Orion underground production rate is designed at up to 510 000 t a month, capped by plant feed capacity.

The underground operation is expected to maintain Tharisa’s current PGM and chrome concentrate production profile, with potential operational benefits from mechanised mining, reduced dilution and improved access to deeper orebodies.

Potential Job Creation
The transition plan includes a partner-driven workforce strategy under which labour ramp-up will be phased in and openpit employees will be retrained or transitioned into underground roles.

Net Present Value/Internal Rate of Return
The project has internal rate of return of more than 25%. A project-specific net present value has not been disclosed.

Capital Expenditure
Transitional capital for the dual Apollo and Orion underground development over the ten-year period is estimated at $547-million. Apollo capital is estimated at $363-million and Orion at $184-million. Peak funding is estimated at $173-million.

Planned Start/End Date
Underground development started with the first blast at the Apollo portal on March 31, 2026.

Apollo is scheduled to deliver first ore in the second quarter of the 2026 financial year and reach steady-state production of 255 000 t a month by the third quarter of the 2029 financial year.

Orion will follow, with first ore targeted for the fourth quarter of the 2031 financial year and steady-state production of 210 000 t a month expected by the third quarter of the 2033 financial year. Orion is designed to reach a capacity of 255 000 t a month, although production will be capped by plant throughput.

Latest Developments
Tharisa announced on May 7, 2026, that Tharisa Minerals had concluded a five-year contract with Cementation Africa for underground mining development and construction works at the Tharisa mine. The agreement follows the first blast at the Apollo portal on March 31, 2026.

The contract is structured as an alliance contracting model, underpinned by an open-book, cost-plus-fee basis rather than a traditional rates-based risk-transfer model. Owner-miner openpit operations will continue concurrently with the underground mine development.

The contract formalises Cementation Africa’s role in supporting Tharisa’s transition to underground mining, which is expected to improve access to deeper orebodies, enhance operational efficiency and extend the mine life.

Key Contracts, Suppliers and Consultants
Cementation Africa (five-year underground mining development and construction contractor under an alliance contracting model); Provest (drilling and installation of anchors and roof bolts, shotcrete application, grout plant operations and grout pack installation services); Enaex Africa (explosives); Komatsu (mining equipment); MacLean Engineering (underground mobile equipment solution); Sandvik (mining equipment and engineering); Dwyka Labs (technical partner for smart mining technologies); RSV (engineering services); Middindi Consulting (geotechnical studies); KLM Consulting Services (structural geological and hydrogeological design); Pivot Mining Consultants (geology and mineral resources); Ukwazi Mining Studies (mine design); AMS Haden (ventilation design); Manyabe Consulting (environmental-impact assessment report); Sight Africa (trackless mobile machinery solutions); Artesium Consulting Services (water balance and mass load studies); Plan A-Head Studies (labour model); Epoch (tailings design); and PQS Profection Quantity Surveyors (basis of estimate).

Contact Details for Project Information
Tharisa Minerals, tel +27 11 996 3500 or email ir@tharisa.com.
Tharisa Minerals investor relations head of investor relations and communications Ilja Graulich, tel +27 11 996 3500 or +27 83 604 0820, or email igraulich@tharisa.com.