With a sequenced approach to its R7.9-billion Mponeng mine expansion and life of mine (LoM) extension project, gold and copper miner Harmony is able to ensure that the project’s roll out will not impact its current production capacities, investor relations head Jared Coetzer tells Mining Weekly.

The expansion of the Carletonville, Gauteng-based Mponeng gold mine, which encompasses three modular projects in one, specifically entails increasing the mine’s depth from an already record-setting 3.9 km to 4.22 km, and serves to extend the mine’s life from a current seven years to 20 years.

“The Mponeng extension project is aimed at mining the Ventersdorp Contact Reef (VCR), the Carbon Leader Reef (CLR) orebodies below existing infrastructure, as well as the TauTona shaft pillar,” he outlines.

The LoM extension project will be achieved through the selective extraction of the high-grade VCR areas to the east and west, through independent access points, while eliminating the lower-grade areas at the centre of the orebody.

Further, the three projects combined de-risk the production profile to ensure Harmony avoids the risk of encountering a “gold gap” in its production portfolio.

At the same time, the easily-accessible first two levels of the CLR – levels 124 and 127 east of the Mponeng shaft – will also be mined.

At the VCR east shaft access points, two additional conventional track-bound production levels –129 and 132 – will be made available with a twin decline system, while at VCR west, accesses to production levels 129, 132 and 135, will be made possible with a trackless machinery ramp from level 126.

The ramp will also offer trackless servicing of conventional track-bound levels supplemented with separate chairlift infrastructure to transport employees.

“Servicing infrastructure will essentially be an extension of the current decline methodology, with a mono-train and chairlift in one decline and a conveyor belt system in the other,” states Coetzer.

The shaft pillars at TauTona and Savuka mines, which were left unmined by the previous owner until the end of those mines’ lives, have two sets of pillars – one on the VCR reef and the other one on the CLR reef, equating to four pillars in total.

A set of extensive studies was launched to investigate the safe extraction of these pillars, after which it was established that only the TauTona pillar could be mined safely with the VCR showing “excellent project metrics”, he confirms.

“The TauTona CLR pillar is still being studied and will be reported on in the future,” says Coetzer.

In terms of permitting and social licence, he says that because the LoM extension project is a brownfields operation, all environmental approvals have already been obtained, and the near-mine community also supports the project as the extension of Mponeng’s LoM will greatly benefit the surrounding community by sustaining jobs, driving local economic activity and funding impactful social investment projects.

Project Capital Requirement, Timeline

Harmony has commissioned underground mining contractor Cementation Africa to undertake the decline shaft infrastructure work to ensure the mine can use trackless mobile machinery.

The overall Mponeng life extension project will be funded on a per shaft level, with a low capital intensity, given the length of the project.

Given the high-grades and strong free cash generation, Mponeng is in a comfortable position to fund this and continue with all capital requirements alongside the extension and still generate positive free cash flows.

In the first half of the 2026 financial year, Mponeng generated almost R5-billion in adjusted free cash flow.

Despite a few delays, first gold from the project is expected in the 2030 financial year, with project completion – including all major capital expenditure complete and all further capital shifting to sustaining activities – expected about a decade from now.

“We have established a centralised project management office to manage the project from a time, budget and quality perspective,” notes Coetzer.

For the 2026 financial year ended June 30, 2026, Harmony has allocated R1.3-billion towards the major capital component of the project, in addition to R1-billion going towards the sustaining capital component of the project.

In addition to the LoM extension project, Harmony Gold is also exploring opportunities for another 100 MW renewable energy solar PV plant, similar to the plant already commissioned at its existing 100 MW Moab Khotsong operation, which will match the 20-year life of the mine to that of the PV plant,” concludes Coetzer.