As pressure mounts on the global mining industry to secure raw materials while reducing environmental harm, a once-overlooked resource is gaining renewed attention: mine tailings. Long regarded as waste, these vast accumulations of finely ground rock are now being reimagined as strategic assets, capable of supporting cleaner steel production, easing supply constraints, and lowering the environmental footprint of mining.
This shift was on full display at the Society for Mining, Metallurgy & Exploration (SME) Annual Conference 2025, held in Denver, Colorado, where research into iron ore tailings reprocessing emerged as a focal point of discussion among industry leaders, researchers, and policymakers.
One presentation, in particular, stood out.
Turning waste into feedstock
Vincent Bailey Arohunmolase, a mineral processing researcher working on sustainable separation technologies, presented an integrated process designed to recover high-grade iron oxides from low-grade iron ore tailings, materials historically written off as unrecoverable waste.
His approach combines dry electrostatic separation with multi-stage froth flotation, a configuration that departs sharply from conventional beneficiation routes. Instead of relying heavily on water-intensive magnetic separation and fine grinding, the flowsheet prioritises early rejection of unwanted gangue minerals using dry electrostatic methods. Subsequent flotation stages are then used to selectively remove residual quartz and aluminosilicate impurities.
The results drew attention across the conference floor. According to data shared at SME 2025, iron oxide grades were upgraded from approximately 25 per cent in tailings feed to more than 93 percent, quality levels suitable for direct-reduced iron (DRI) feedstock used in low-carbon steelmaking.
Why it matters now
Beyond metallurgical performance, the work resonated because it addresses several converging pressures facing the mining and steel industries.
“Large volumes of iron remain locked in tailings simply because older processing routes were not designed to recover them efficiently,” Arohunmolase explained during the session. “By integrating established separation technologies more intelligently, we can unlock this value while reducing environmental risk and operational cost.”
That message struck a chord with mining companies grappling with declining ore grades, stricter environmental regulations, and growing scrutiny over tailings storage facilities, now widely recognised as financial, social, and environmental liabilities.
Vinicius Romano, Business Transformation and Innovation Specialist at Vale Brazil, followed the presentation closely and later reflected on its implications. Achieving iron oxide grades above 93 percent from tailings, he noted, “fundamentally changes how the industry should define waste.”
From liability to strategic asset
Geological and processing experts at the conference placed the research within a broader industry reckoning. Dr Warwick Crowe, Chief Geologist at Titan Minerals Limited, described tailings reprocessing as “a realistic pathway for converting long-term environmental liabilities into strategic mineral assets.”
From an academic standpoint, Professor Corby Anderson of the Colorado School of Mines, Director of the Kroll Institute for Extractive Metallurgy, highlighted the technical significance of integrating electrostatic separation with staged flotation. The approach, he observed, directly tackles long-standing challenges related to selectivity and mineral liberation in fine tailings, an issue that has historically limited recovery efficiency.
Importantly, the relevance of the research extends beyond established mining jurisdictions.
Implications for developing economies
International observers emphasised the potential impact of such technologies in mineral-rich developing countries, where large volumes of historical tailings coexist with rising domestic demand for steel.
Professor Olugbenga Elijah Okunlola, an economic geologist at the University of Ibadan, pointed out that tailings reprocessing could play a critical role in strengthening domestic mineral value chains. For countries seeking to reduce import dependence while improving environmental outcomes, he argued, reprocessing offers “a rare alignment of economic, industrial, and sustainability objectives.”
A circular turn for mining
Discussions at SME 2025 repeatedly returned to a central theme: mining is entering an era where efficiency is no longer measured solely by ore throughput but by how well operations manage what they leave behind.
With tailings facilities increasingly scrutinised by regulators, investors, and host communities, reprocessing strategies that simultaneously reduce tailings volume and generate marketable products are gaining momentum. They fit squarely within circular-economy thinking, extracting maximum value from materials already disturbed, while minimising new environmental impacts.
Arohunmolase’s work was frequently cited during the conference as an example of how scientifically validated mineral processing strategies can help align mining operations with broader decarbonisation and resource-security goals.
As global demand for cleaner steel accelerates and pressure builds to secure reliable iron supply chains, the industry’s future may depend not only on what lies underground but also on what has already been mined, discarded, and overlooked.
