Pan African Mine Tailings – Sustainable Mine Management
The closure of Johannesburg’s “Top Star Drive-in” in 2008 marked a poignant moment. Top Star wasn’t just a venue for moviegoers to catch films with a panoramic view of the city; it was a cultural staple. Its shutdown was attributed more to the rise of cable television than its unique placement atop the Ferreira dump, an old gold mine tailings site. Such a location for a drive-in would be unthinkable today.
Over the past decade, the world has seen an increase in both the frequency and severity of tailings dam failures. This trend is largely due to the mining of lower-grade deposits, which results in larger tailings dams, as reported by Earthworks.org.
For instance, the Samarco iron ore mine’s tailings dam in Brazil ruptured in 2015, resulting in 19 fatalities. A more tragic event unfolded in 2019 with the collapse of the Brumadinho tailings dam at the Corrego do Feijao mine in Brazil, claiming nearly 300 lives. More recently, in 2022, the Jagersfontein tailings dam at a diamond mine in South Africa’s Free State province failed, resulting in two deaths.
These catastrophes have not only caused loss of life and property damage but also unleashed vast amounts of toxic waste into the environment. Responding to this, the UN Environment Programme, along with Principles for Responsible Investment and the International Council on Mining and Metals (ICMM), introduced the Global Industry Standard on Tailings Management in 2020.
Globally, mining companies are estimated to dispose of approximately 180 million tons of hazardous mine waste annually, with around 18,000 tailings dams worldwide, 3,500 of which are active, according to Earthworks.org.
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What are tailings?
Tailings, the byproduct of mining operations, can be stored either underground or on the surface. The safety and potential risk of these storage sites depend on their design, location, exposure to extreme weather, and the type of waste stored.
For example, waste from South Africa’s underground gold mining, which began post-1890, contains not just silica sand and heavy metals but also toxic substances and, in certain areas, uranium, alongside a small amount of leftover gold. The dust and runoff from these sites have compromised air quality, water resources, and public health, exacerbated by unauthorized residential construction and recreational activities on these sites.
Fortunately, advancements in processing techniques and bulk mining now allow for the economical extraction of residual gold from tailings storage facilities (TSFs), turning a profit while simultaneously addressing environmental concerns. However, it’s important to note that even after reclamation, these areas are not suitable for housing development.
In South Africa, numerous companies, ranging from large to small and including those specializing in mine waste management, are re-mining gold TSFs. Some are engaged in underground mining concurrently.
Older gold TSFs can yield gold concentrations of 0.1-2.5 grams per ton. Although insufficient for deep-level mining, these grades are economically viable for contemporary surface mines and tailings retreatment projects. For instance, Pan African Resources, which operates the historic Barberton Mines in Mpumalanga, ventured into tailings treatment about six years ago, aligning with its dedication to responsible mining practices. The Barberton Mines Tailings Retreatment Project (BTRP) boasts a head grade of 1.6-2.2 grams per ton, achieving recovery rates of 27-43%. In comparison, the Barberton complex’s three underground mines—Fairview, Consort, and Sheba—feature head grades of 5-14 g/t with recovery rates exceeding 90%.
Pan African also operates the Elikhulu tailings retreatment facility at the Evander Mine and has recently agreed to acquire several TSFs from Mintails, currently undergoing a business rescue process akin to the US’s Chapter 11 reorganisation.
The Mintails project
All of central Johannesburg’s historic gold waste heaps have been flattened, yet substantial volumes of gold tailings remain on the city’s outskirts.
The Mintails tailings near Krugersdorp, on Johannesburg’s western boundary, have long been a concern for local residents. This area has turned into an environmental blight, characterized by decaying structures and contaminated pools, and has become a hotspot for illegal mining activities and criminal behavior. The financial difficulties faced by its former owners meant no funds were allocated for environmental clean-up, making the site less attractive to prospective investors.
By reprocessing the Mintails Tailings Storage Facilities (TSFs), Pan African aims to embody its commitment to exceeding regulatory standards.
Pan African has identified approximately 120 million tons of material in the Mintails TSFs suitable for re-mining, with an average grade of 0.3g/t, equating to around 1.1 million ounces of gold. The company plans to employ hydro mining techniques, which involve using high-pressure water jets to mobilize the material, then transporting the slurry to a state-of-the-art processing facility. This method is recognized for its cost efficiency and minimal environmental impact.
Cobus Loots, the CEO, stated, “These tailings are a significant untapped resource for both Pan African and the surrounding community. Processing them could boost Pan African’s output by 25%, or an additional 50,000oz per year, over 13 years, while also aiding in the environmental restoration of the area. Our operations will foster socio-economic benefits for local communities and suppliers, including job opportunities, skill development, and supplier enhancement, improving living standards in Krugersdorp.”
Pan African has secured the necessary funding of R2.5 billion ($129 million) to acquire and process the tailings, under favorable terms. The company aims to start constructing the processing plant, pending regulatory approvals, by June, with the goal of reaching full production by December 2024. Following the project’s completion, the investment is expected to be recouped within approximately three and a half years, based on current gold prices in South African rand.
Additionally, there are plans to build a solar PV facility on the premises to ensure a reliable power source and diminish the company’s carbon footprint. Pan African recently inaugurated a 9.9MW solar farm at Evander, with plans for expansion, and intends to construct another solar plant at Barberton.
Conclusion
Mining operations don’t have to result in negative legacies. Pan African’s significant investments in the Mintails project and renewable energy infrastructure in South Africa are set to secure its long-term presence in the country, while delivering advantages such as employment, skill development, and environmental enhancement for the communities near its sites.
