Midtier gold miner Pan African Resources aims to increase gold production by about 50 000 oz/y by 2025 through its Mintails project, which will increase the miner’s yearly production to about 250 000 oz.

The project consists of the Mogale Tailings Retreatment (MTR) plant which will process the Mogale tailings storage facilities (TSFs) and the Soweto Cluster TSFs, both located near Krugersdorp, in Gauteng, which stem from historic mining activities spanning about a century.

Historic miners of gold exploiting the mineral-rich Witwatersrand basin mined into high-grade underground reefs, processing ore through various technologies. Consequently, low-grade gold-containing material landed up in TSFs, which can now be economically extracted as a result of the higher gold price and modern processing techniques, explains Pan African Resources investor relations head Hethen Hira.

Pan African Resources acquired the TSFs for R50-million and conducted a definitive feasibility study (DFS) in 2022 to determine if the low-grade tailings could be economically processed.

The results of the study were positive and revealed that the substantial mineral reserves, totalling a combined 2.1-million ounces of gold, in the TSFs could be economically extracted through a high throughput reprocessing facility.

The Mogale TSFs contain about 126-million tonnes of processed tailings material in numerous facilities on surface.

The economic potential of the project is further enhanced with Pan African’s confirmation drilling into the 2L16 and 2L24 TSFs at the Soweto Cluster to determine their contained gold grade, which accounts for 110-million tonnes of the available 133-million tonnes at the Soweto Cluster.

These evaluations serve to extend the life-of-mine of the Mintails project from a previous estimate of 13 years to 21 years, and enhance yearly production from an initial 50 000 oz/y to 60 000 oz/y.

Pan African informs Mining Weekly that additional studies will be conducted on the remaining TSFs that fall within the ambit of the project to further explore their potential.

The company is on track to bring the MTR plant into production on time and within budget, while aiming to make a positive difference to the environment and communities in the area, and create sustainable economic benefits for the region.

In line with the DFS findings, Pan African plans to construct an 800 000 t a month processing plant, modelled after its Elikhulu tailings retreatment plant, situated at its Evander Mines near Secunda in Mpumalanga, and its Barberton tailings retreatment plant, situated in Barberton, also in Mpumalanga.

Construction costs are estimated at R2.5-billion, and the project is expected to be financially viable according to the DFS, with payback anticipated within three-and-a-half years, after commissioning.

Optimisation and value engineering activities were completed, following completion of the DFS in 2022, while the funding package was finalised in July this year.

Environmental approvals for construction were also obtained from the Department of Mineral Resources and Energy (DMRE).

Site clearance started in July this year and significant progress has been made, with steady-state production expected by December 2024, says Hira.

Pan African Resources will mine the low-grade surface material in the TSFs which have an average grade of about 0.3 g/t.

Following the tailings processing and retreating process, the company will develop modern TSFs, into which it will deposit the retreated tailings it cannot otherwise use as backfill in legacy mine shafts, thereby reducing the size of the pollution plumes and, eventually, eradicating them.

Legacy Challenges
While the legacy Mintails sites offer significant value as one of the two last remaining surface tailings facilities of substantial tonnage in South Africa, the project has encountered various challenges.

Hira explains that the previous operators failed to mine the deposits efficiently, leading to their liquidation and a considerable rehabilitation funding liability.

Pan African Resources also had to tackle severe environmental degradation and water pollution, as well as illegal mining activity.

Illegal mineworkers are targeting the underground structural and support pillars left behind by previous operators – the removal of which is dangerous and is likely to result in shaft collapses.

The company intends to pump reprocessed tailings from the Mintails project into these underground shafts, making it difficult for illegal mining to continue, adds Hira.

Pan African Resources will also implement various security measures, including attempts at greater collaboration with the South African Police Service, who will act on incidents with the support of the South African National Defence Force. The latter was recently deployed to help combat illegal mining.

Regarding rehabilitation of the western Gauteng region, discussions with the DMRE regarding environmental mitigation plans and rehabilitation for the project benefited from Pan African Resources’ successful history of operating tailings retreatment plants.

Meanwhile, the company’s investment of R2.5-billion in the Mintails project is one of the largest recent investments for Gauteng, as well as South Africa, adds Hira.

There has been significant disinvestment in the Krugersdorp region, as mines have closed and industries scaled down; therefore, Pan African Resources has prioritised its expenditure towards local suppliers and labour, thereby ensuring that a substantial amount of goods and services are procured locally, he concludes.