Dr Margreth Tadie, a lecturer in the Department of Process Engineering, is among a selected group of Stellenbosch University (SU) staff participating in the Future Professors Programme (FPP), an initiative of the Department of Higher Education and Training. The FPP aims to develop a transformed next generation of South African professors across all disciplines. Read more about her career journey.
Chemical engineer Dr Margreth Tadie aims to move mountains in the mining sector – mountains of mining waste. It is her mission to rid mining towns of mounds and dams of tailings, and to make the most out of the waste in the process.
“Tailings are what's left after high-value minerals have been mined and extracted from ore," explains this lecturer in SU's Department of Chemical Engineering. “What's left is a mass of material that has been displaced from where it was mined."
More specifically, Dr Tadie's sights are on tailings generated more than 60 years ago, when technology was not yet advanced enough to extract all possible economic value during the mining process. “I look at how the material can be reprocessed so that the valuable metals that are still left can be extracted. This creates an opportunity to remediate the land and surrounding areas where tailings lie, and also provides an opportunity for communities to gain economic value from it.
“To mitigate the impact of tailings is a grand challenge that requires sustainable solutions. It requires us to rethink the purpose of the material, and come up with ways to recover and create new value," adds Dr Tadie.
That means moving away from using often toxic lixiviants, including cyanide, to more ecological methods to extract metals such as gold, copper and the platinum group. “It excites me to develop new processes, understand and optimise current ones, and shed new light on things," she says.
Her research also goes beyond the technical side of matters, as she is constantly re-evaluating the lifecycle cost and environmental and social impact of proposed processes. “Companies are increasingly seeing the value of doing something about tailings, partly because legislation is increasingly forcing them to do so. They know that ignoring it can be catastrophic, as we saw in 2019 in Brazil, when a tailings dam broke and flooded the nearby mine and the land around it with millions of litres of toxic mud. It cost billions to remediate."
Career path
Dr Tadie's current work is being funded through the Royal Society's Future Leaders African Independent Researchers (FLAIR) fellowship programme, and she is also part of the inaugural 2020 intake of the Future Professors Programme (FPP) of the Department of Higher Education and Training (DHET).
While the former supports her research and academic endeavours through a monetary grant and training, the latter is solely focused on developing her as an academic. The FPP provides dedicated mentorship, peer-to-peer discussions, and interaction with leading academics worldwide. “I am very fortunate to be part of it," she says.
Over the past year, she has been finetuning her research focus and career path. She also acknowledges the valuable support of the FPP team and fellows in helping her cope with the challenges that the COVID pandemic has created for academics.
She enjoys the sense of freedom in engaging with academics from other institutions and from different backgrounds and disciplines, and to share experiences collegially. “The FPP also creates a safe space to evaluate your career and your strengths and weaknesses, and to work on them where needed," she adds.
Wants to see Africa move forward
When, as a teenager, she had to start thinking of a career, the mining sector was last on her list. “Growing up in Zimbabwe, we moved a lot between various mines because my father was a metallurgist. I wanted to spread my wings as far away from mining as possible," she says.
After school, she completed a BEng degree in Chemical Engineering cum laude at Zimbabwe's National University of Science and Technology, followed by an MEng at the University of KwaZulu-Natal in 2009 and a PhD at the University of Cape Town in 2015.
In the process, she realised that the mining sector was, ironically, exactly where she had to be. Not only did she understand the needs and fears of mining communities intimately, but she was able to use her skills to help address the environmental and economic problems they faced.
Admitting that her science is driven by a desire to help people, Dr Tadie says: “Mining plays a big role in Africa. I could run away from it or become relevant by working in a field that I know. I really, really love Africa, and I want to see it move forward. I want us to use the resources and mineral wealth at our disposal. I want to use my talents to benefit my continent, my home."
