Key points
- South Africa holds about 40% of global manganese reserves, and with Ghana and Gabon accounts for up to 75% of production.
- About 80% to 90% of manganese demand comes from steelmaking, with no known substitute, while battery-grade manganese sulphate is emerging.
- High power costs, rail and port constraints and foreign competition have shut smelters such as Transalloys and Assmang’s Cato Ridge.
Africa holds the manganese the world cannot do without, yet most of the value leaves the continent as unprocessed ore.
That gap, a Stellenbosch University researcher told the Mintek-SCi 2026 conference in Johannesburg on Oct. 2, is the opportunity research and innovation must close.
Margreth Tadie, an associate professor of chemical engineering and holder of the African Rainbow Minerals geometallurgical research chair, used manganese as her case study in a keynote on critical minerals.
South Africa holds about 40% of global reserves and is the largest producer. Add Ghana and Gabon, and three African countries account for up to 75% of world output.
“However, much of the processing capacity and value addition takes place outside of Africa,” she said.
Why manganese counts as critical
Tadie stressed that criticality is never fixed. Supply, demand, geopolitics, technology and shifting markets all move the line. Manganese is the twelfth most abundant element in the Earth’s crust, so scarcity is not the issue.
Instead, its criticality rests on economic importance: roughly 80% to 90% of demand comes from steelmaking, and there is no known substitute. Meanwhile, battery-grade manganese sulphate is opening a second market.
South Africa classifies manganese as highly critical. Consequently, Tadie argued, the country should use science to supply refined material rather than raw ore, and it should do so close to where extraction happens. “We know our national problems,” she said.
The obstacles are real. High electricity costs, rail and port bottlenecks and international competition have squeezed local processing, contributing to the closure of smelters such as Transalloys in Mpumalanga and Assmang’s Cato Ridge operation in KwaZulu-Natal.
What the research chair is doing
Tadie’s own work shows how academia and industry can collaborate on those problems. Geometallurgy, she explained, connects disciplines across the mining value chain and helps companies understand an orebody before mining and processing decisions are locked in.
Projects under the ARM chair have examined manganese ore textures, chemical signatures and machine-learning models.
In addition, researchers are studying the reprocessing of manganese-bearing tailings, including the difficult task of separating manganese from iron when the two sit together in solid solution.
That complexity, she said, is exactly why South Africa needs multidisciplinary innovation hubs that link fundamental research to industrial challenges.
“The opportunity in this generation is really not simply to discover the new orebody or to extract the minerals,” Tadie concluded. The task is to use science, technology and innovation to build a more competitive and sustainable minerals economy.
