In the heart of South Africa’s coal-dependent energy sector, a groundbreaking study led by Dumisane Mahlangu from the University of South Africa (UNISA) is turning industrial waste into a valuable resource for the construction industry. The research, published in the journal ‘Sustainable Chemistry for the Environment’ (translated as ‘Sustainable Chemistry for the Environment’), offers a promising solution to the mounting challenge of waste management in the energy sector.
South Africa’s reliance on coal-fired power plants has led to a surge in the production of gypsum, a by-product of flue gas desulfurization, as well as fly ash and basic oxygen furnace slag. These industrial by-products have traditionally posed disposal challenges, but Mahlangu’s research is changing the narrative. “We saw an opportunity to repurpose these materials into eco-friendly construction materials,” Mahlangu explains. “This not only addresses waste management issues but also provides a sustainable alternative for the construction sector.”
The study proposes a novel binder developed by blending varying proportions of wet flue gas desulfurization gypsum (WFGDG), fly ash (FA), and basic oxygen furnace slag (BOFS). The optimal mix, containing 10 wt% FA and 40 wt% BOFS, achieved a compressive strength of 4.4 MPa after 90 days of ambient curing at 40°C. This exceeds the South African National Standard (SANS) 10145 requirement for Class III mortar, making it suitable for load-bearing applications.
The commercial implications for the energy sector are significant. By repurposing industrial by-products, power plants can reduce disposal costs and potentially generate additional revenue streams. “This research opens up new possibilities for the energy sector to contribute to the circular economy,” Mahlangu notes. “It’s a win-win situation where waste is transformed into a valuable resource, and the construction industry gains access to sustainable materials.”
The study also highlights the environmental benefits. The composite bricks developed in the research meet the safety criteria of SANS 227:2007 and ASTM C34–13, ensuring they are safe for use in construction. This aligns with global trends towards sustainable and green building practices.
Looking ahead, this research could shape future developments in the field by encouraging further exploration of waste-derived construction materials. As the world grapples with the challenges of waste management and sustainability, innovative solutions like this one offer a beacon of hope. “We hope our research will inspire more studies and practical applications in this area,” Mahlangu concludes. “The potential is immense, and the benefits are far-reaching.”
In an era where sustainability and economic viability are paramount, Mahlangu’s research stands as a testament to the power of innovation in addressing complex challenges. As the energy and construction sectors continue to evolve, this study could pave the way for a more sustainable and economically robust future.