UNIVERSITY PARK, Pa. — Is there a way to turn waste into a useful resource and at the same time reduce environmental degradation from closed mines? That’s what visiting South African scholar Nemapate Ndivhuwo wants to find out.
Ndivhuwo visited Penn State during fall semester 2019 from the University of Venda, in Limpopo Province, South Africa, as part of its University Capacity Development Programme.
The program is a partnership between three South African universities: the University of Venda, University of Cape Town and University of Fort Hare, with two U.S. universities: the University of Arizona and Penn State, said Brian King, professor of geography in the College of Earth and Mineral Sciences, and Ndivhuwo’s sponsor.
The program, funded by South Africa’s Department of Higher Education and Training, supports graduate research on climate risk, resilience and sustainable development, and is intended to help diversify the country’s higher-education sector, King said.
Ndivhuwo conducted research in the Fletcher L. Byrom Earth and Mineral Sciences Library and interviewed faculty members across the University to support his doctoral research on the impacts of climate change on post-operational phases of mining in South Africa.
Historically, mining — especially for gold — has been the backbone of the South African economy, Ndivhuwo said, so it’s no surprise that as a student he became interested in mining, geology, and how climate change is affecting the mining industry.
“South Africa is highly dependent on minerals, so I was keen on teaching students about mining and geology. I was curious about river and groundwater contamination from mining activities,” Ndivhuwo said.
Gold mining and other types of mining has decreased significantly in recent years due to increased extraction costs, aging equipment, and labor and safety problems.
“Since 2001, a lot of companies did not want to mine due to the expense,” Ndivhuwo said. “As a result, reprocessing of tailings dams to reclaim precious metals is gaining momentum.”
A tailings dam is an earth embankment made from mining waste, rocks and sand. They often contain a mixture of toxic and inert materials. Some tailings dams hold back ponds of water and liquid byproducts from mining.
“Tailings dams are significant sources of ambient dust, surface and groundwater contamination, soil contamination of arable land, and also acid mine drainage,” Ndivhuwo said. “These have potential consequences on the health of those communities that live within the vicinity.”
Ndivhuwo’s master’s degree research focused on methods for establishing the mineral composition of tailings dams and the potential for gold processing and rehabilitation.
“It’s not expensive to mine the tailings dams; one can even use high-pressure water to wash the gold out in some cases,” he said.
For his doctoral research, Ndivhuwo will employ multiple approaches in establishing the mineral composition of tailings dams and how those minerals are dispersing into the environment through the air, water and soil.
“Every site has a different geology,” he explained.
As a scientist, Ndivhuwo said his goal is to understand the geology of tailings dams and to understand the link between climate change and mining.
“Penn State and the Department of Geography have long-standing engagements with the African continent,” King said. “Additionally, this program demonstrates important opportunities to leverage institutional expertise in climate science and sustainable development to support the training of the next generation of scholars, not just within the United States, but also the Global South. In partnering with this initiative, Penn State is fulfilling its mission as a land-grant institution for not only the Commonwealth of Pennsylvania, but also the world.”
As part of that next generation of scholars, Ndivhuwo said he wants to teach future students, and also advise the government.
“When I finish my Ph.D., I will teach the next generation about climate change and mining,” Ndivhuwo said. “Also, if possible, I would like to help the government create policies about climate change and mining. When they plan mining, they must also plan how to deal with the effects of climate change.”