Pan African Mine Tailings – Sustainable Mine Management
The closure of the “Top Star Drive-in” in Johannesburg in 2008 was a significant event. More than just a spot for watching films against the city’s skyline, Top Star was a beloved institution. Its closure was largely blamed on the emergence of cable TV, rather than its unusual location atop the Ferreira dump, a site of old gold mine tailings. Nowadays, such a setting for a drive-in cinema would be unimaginable.
In recent years, there has been a noticeable rise in the frequency and severity of tailings dam failures worldwide. This increase is primarily due to the extraction of lower-grade ores, necessitating larger tailings dams, as Earthworks.org notes.
For example, in 2015, the tailings dam at the Samarco iron ore mine in Brazil burst, leading to 19 deaths. An even more devastating incident occurred in 2019 when the Brumadinho tailings dam at the Corrego do Feijao mine in Brazil failed, resulting in nearly 300 fatalities. More recently, in 2022, the collapse of the Jagersfontein tailings dam at a diamond mine in the Free State province of South Africa led to two deaths.
These disasters have not only resulted in loss of life and damage to properties but have also released large quantities of toxic sludge into the environment. In response, the UN Environment Programme, Principles for Responsible Investment, and the International Council on Mining and Metals (ICMM) launched the Global Industry Standard on Tailings Management in 2020.
It is estimated that mining operations worldwide dispose of around 180 million tons of toxic waste each year, with about 18,000 tailings dams globally, of which 3,500 are active, as per Earthworks.org.
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What are tailings?
Tailings are essentially the waste material from mining processes, which can be stored either under the surface or over it. The risk and safety of these storage facilities depend on their construction, location, susceptibility to hazardous weather, and the nature of the waste stored.
In South Africa, mining waste from underground gold extraction post-1890 contains silica sand, heavy metals, toxic substances, and occasionally uranium, along with a minor amount of residual gold. The dust and runoff from these areas have affected air and water quality and public health, further aggravated by illegal housing developments and recreational activities around these sites.
Thankfully, modern processing methods and large-scale mining techniques now make it feasible to economically recover leftover gold from tailings storage facilities (TSFs), providing financial gains and addressing environmental issues. However, it’s worth noting that these reclaimed areas are still unsuitable for residential development.
Various firms in South Africa, both large and small, including those specialising in mine waste management, are now reprocessing gold TSFs. Some are also involved in concurrent underground mining.
The older gold TSFs offer yields of 0.1-2.5 grams of gold per ton, which, while not sufficient for deep-level mining, are economically viable for modern surface mining and tailings retreatment endeavours. For example, Pan African Resources, the operator of the renowned Barberton Mines in Mpumalanga, embarked on tailings treatment approximately six years ago, in line with its commitment to sustainable mining practices. The Barberton Mines Tailings Retreatment Project (BTRP) reports a head grade of 1.6-2.2 grams per ton, with recovery rates between 27-43%. For context, the head grades of the three underground mines at the Barberton site—Fairview, Consort, and Sheba—are between 5-14 g/t, with recovery rates above 90%.
Additionally, Pan African manages the Elikhulu tailings retreatment operation at the Evander Mine and has recently finalised an agreement to purchase several TSFs from Mintails, which is currently undergoing a business restructuring process similar to Chapter 11 reorganisation in the US.
The Mintails project
The once towering gold mine waste heaps that defined central Johannesburg’s skyline have now been levelled, yet significant amounts of gold tailings still skirt the city’s periphery.
The Mintails tailings, located near Krugersdorp on Johannesburg’s western fringe, have been a longstanding issue for the local populace. The site has deteriorated into an environmental eyesore, plagued by old, rusting structures and polluted water bodies, and has become notorious for illicit mining operations and criminal activities. The financial woes of its previous proprietors left the site without the necessary funds for environmental rehabilitation, deterring potential investors.
Pan African’s strategy to reprocess the Mintails Tailings Storage Facilities (TSFs) reflects its pledge to surpass standard regulatory requirements.
The company estimates that the Mintails TSFs contain about 120 million tons of reprocessable material, with an average gold content of 0.3g/t, translating to roughly 1.1 million ounces of gold. Pan African intends to utilize hydro mining techniques, which involve blasting the material with high-pressure water to create a slurry, then transporting this mixture to a modern processing facility. This approach is lauded for its efficiency and minimal ecological footprint.
CEO Cobus Loots commented, “These tailings represent a substantial untapped asset for both Pan African and the community at large. Reprocessing them could increase Pan African’s production by 25%, or an extra 50,000oz annually, over a span of 13 years, whilst contributing to the site’s environmental recovery. Our initiatives will also generate socio-economic benefits for the local populace and suppliers, such as employment opportunities, skill enhancement, and supplier development, thereby elevating the quality of life in Krugersdorp.”
Pan African Resources has arranged the required R2.5 billion ($129 million) funding to purchase and reprocess the tailings, on advantageous terms. The company plans to commence construction of the processing facility, contingent on obtaining the necessary permits, by June, aiming for operational readiness by December 2024. The return on this investment is anticipated within about three and a half years, based on the prevailing gold prices in South African rand.
Furthermore, there are proposals to establish a solar PV installation on the site to provide a consistent energy supply and reduce the company’s carbon emissions. Pan African recently unveiled a 9.9MW solar power station at Evander, with intentions to expand it soon, and is also planning a second solar facility at Barberton.
Conclusion
The aftermath of mining activities doesn’t necessarily have to be detrimental. Through its substantial investment in the Mintails venture and in sustainable energy solutions within South Africa, Pan African is poised to solidify its future operations in the country, whilst bringing benefits like job creation, skill advancement, and environmental improvements to the communities surrounding its operations.
