Name of the Project
TGME underground gold mining project.

Location
Mpumalanga, South Africa.

Project Owner/s
Gold mining development company Theta Gold Mines.

Project Description
The project aims to restart historical underground gold mines in Mpumalanga, a prolific gold-mining region.

The project is targeting the Beta, Rietfontein, Frankfort and Clewer-Dukes Hill-Morgenzon (CDM) mines.

In the base case, the project has a mine life of 12.9 years, delivering production of 1.24-million ounces of contained gold over the life-of-mine (LoM) at a processing rate of 540 000 t/y to initially recover 1.08-million ounces of gold.

The project aims to produce 30 000 t a month from the Beta mine, 15 000 t a month from the Rietfontein mine, 15 000 t a month from the Frankfort mine and 10 000 t to 20 000 t a month near the end of the CDM mine’s LoM. The existing mining infrastructure will be used, with the addition of new accesses, underground development and predevelopment of the mining grids to access the planned mining areas at Beta, Frankfort and CDM.

At Rietfontein, the existing adits and underground development will be used with the addition of new development ends, a new decline and the extension of an existing decline.

The mining strategy for the underground operations is to apply mechanised longhole drilling to narrow-reef mining to selectively mine out only the reef channel, with minimal dilution at Beta, Frankfort and CDM.

Rietfontein will be mined conventionally using shrinkage stoping, with hybrid loading methods between trackless load-haul-dump and rail-bound locomotives.

The processing plant will have a feed capacity of 45 000 t a month .

Potential Job Creation
As of the end of October 2025, the on-site team totalled 137.

Net Present Value/Internal Rate of Return
In the base case, the project has a net present value, at a 10% discount rate, of $324-million at an average $1 642/oz and an internal rate of return of 65%. Based on these figures, the project has a forecast after-tax payback period of 31 months.

Capital Expenditure
The estimated development capital or peak funding requirement is $77-million.

Planned Start/End Date
Theta will be commissioning the plant by end of 2026 and processing ore in the first quarter of 2027.

Latest Developments
Theta Gold Mines is accelerating the TGME gold plant by procuring a 900 kW ball mill circuit from MechProTech.

MechProTech’s entire mineral processing equipment range is manufactured in South Africa. The on-site risk is lower, owing to all equipment being assembled and tested in house.

The company’s locally manufactured package will be delivered in 25 weeks. It has two high-performance ball mills, an integrated feed system and containerised motor control centre panels. To ensure a smooth commissioning phase, first fills of lubrication and grinding media are included.

“This procurement is not just a major equipment milestone. It’s a clear signal of our commitment to commission the plant by the end of 2026,” Theta Gold Mines executive chairperson Bill Guy has said.

The timeline aligns with Theta’s plug-and-play construction model, designed to accelerate build speed and reduce capital expenditure (capex).

Under the this model, the mills and supporting infrastructure will be built in the factory and then trucked to the site to fast-track construction and reduce capex.

Importantly, the mill comes with a performance guarantee and includes full commissioning support, on-site training and a robust service level agreement that ensures immediate operational readiness.

Civil works are already under way.

Key Contracts, Suppliers and Consultants
Met63 (detailed design and costing of processing plant designed for a feed capacity of 45 000 t a month); YRC (construction of gold plant, tailings storage facility and wastewater dams); and PICM and Mainpro (critical earthworks and civil phase of TGME); RM Process and Eco Elementum (processing plant and owners' engineers – civil engineering); and MechProTech (mill circuit).

Contact Details for Project Information
Theta Gold Mines, tel +61 2 8046 7584 or email info@thetagoldmines.com.