By Charles Pitts
PERTH, Australia : Rio Tinto Group (NYSE: RIO) announced Tuesday a significant expansion of its manganese exploration program, a strategic pivot designed to capture market share as the United States accelerates its domestic critical mineral production.
The mining giant’s decision follows a series of breakthroughs in North American supply chains, most notably the progress at South32’s Hermosa project in Arizona. By aggressively moving into the manganese space, Rio Tinto signals that the era of treating manganese as a secondary “steel-only” commodity has ended.
The move is not merely a diversification play. It is a direct response to a shifting geopolitical landscape where the control of battery-grade manganese is becoming as vital as lithium or nickel.
The Hermosa Catalyst
For decades, manganese was the forgotten workhorse of the industrial world. It was essential for steel but lacked the “glamour” of copper or gold. That changed when the U.S. Department of Defense and the Department of Energy began pouring billions into domestic critical mineral supply chains.
South32’s Hermosa project became the poster child for this domestic surge. As the first U.S. mine to be fast-tracked under the FAST-41 process, Hermosa proved that high-grade manganese extraction on American soil was not just possible, but a matter of national security.
Rio Tinto’s acceleration is a recognition that they cannot afford to be spectators in the global battery revolution. While the company has long dominated the iron ore market, the “Green Steel” transition and the EV battery pivot are forcing a reassessment of its portfolio.
“They aren’t just looking for ore; they’re looking for a seat at the table,” says one industry analyst. “If Rio Tinto doesn’t secure its own manganese pipeline now, they’ll be buying it back from their competitors at a premium by 2030.”
Manganese: The Silent Engine of the Cathode
The strategic calculus here isn’t subtle: Manganese is no longer just about hardening steel. It is becoming the preferred stabilizer in next-generation EV batteries.
As automakers move away from high-cobalt chemistries due to ethical and cost concerns, Lithium-Manganese-Iron-Phosphate (LMFP) and high-manganese NCM (Nickel-Cobalt-Manganese) batteries are gaining traction. The demand for high-purity manganese sulphate (HPMSM) is projected to outpace supply by late 2026.
Rio Tinto’s exploration surge is targeting high-grade deposits that can be processed into this high-purity form with minimal environmental impact. This aligns with the broader industry trend toward reducing the carbon footprint of the extraction process itself. We have already seen a similar shift in processing technologies, such as the death of the wet mill, which redefined efficiency in the steel industry.
Breaking the Stranglehold
Currently, the world depends on a dangerously narrow supply chain for manganese. While South Africa and Australia are major ore producers, China controls over 90% of the high-purity manganese refining capacity.
That’s not a rounding error. That’s a crisis.
The U.S. domestic supply surge, led by Hermosa and bolstered by junior miners in the upper Midwest and Canada, is the first real challenge to this dominance. Rio Tinto’s entry into the exploration fast-lane adds significant weight to the Western alternative.
The numbers are brutal: Global demand for battery-grade manganese is expected to grow nine-fold by 2030. Rio Tinto’s internal projections reportedly suggest a supply gap of approximately 475 kilotons by 2027. That’s a lot, sure. But in the context of a 2026 market that is already tightening, it’s a looming wall.
Exploration Strategy and Geographic Focus
While Rio Tinto has remained tight-lipped about specific drill locations, sources indicate a renewed focus on the Northern Territory in Australia and potential joint ventures in North America. The goal is vertical integration: controlling the mineral from the moment it leaves the ground to the moment it enters the precursor cathode active material (pCAM) stage.
This isn’t exploration for exploration’s sake. This is tactical.
By leveraging their existing infrastructure in the Pilbara and their massive balance sheet, Rio can move from discovery to development at a speed that junior miners simply can’t match. They are hammering out a new blueprint for the “Big Four” diversified miners: be big, but be fast.
The focus on manganese also serves as a hedge. As iron ore prices face long-term pressure from China’s slowing property sector and the rise of scrap-based EAF steelmaking, critical minerals provide a necessary buffer. Manganese, being essential to both the old world (steel) and the new world (batteries), is the perfect bridge.
The 2026 Inflection Point
2026 marks the inflection point for the manganese market. The chickens are finally coming home to roost for manufacturers who assumed cheap, processed minerals from overseas would always be available.
With the U.S. Treasury’s strict 30D and 45V tax credit requirements under the Inflation Reduction Act, “Foreign Entities of Concern” (FEOC) rules are tightening. Any battery containing manganese processed in China will soon be ineligible for full subsidies.
This has created a vacuum. Rio Tinto is rushing to fill it.
The strategic shift is detailed further in the Skillings Mining Review March 2025 archives, which noted the early warning signs of this supply-demand mismatch. What was once a theoretical concern is now an operational reality.
Operational Challenges and Geological Reality
But you can’t disrupt geology. Manganese deposits are common, but deposits that are both high-grade and “clean”: meaning they lack the impurities that make battery-grade refining expensive: are rare.
Rio Tinto’s technical teams are reportedly deploying advanced AI-driven geological modeling to identify these “sweet spot” deposits. This technology allows for a more surgical approach to drilling, reducing the time from initial survey to resource definition.
“The industry has spent the last decade obsessed with lithium,” says a veteran geologist. “Ironically, while everyone was fighting over the white gold, the manganese floor was being swept out from under them. Rio isn’t making that mistake again.”
What Happens Next
The timeline for Rio Tinto’s expanded exploration is aggressive. Initial results from their 2026 spring drilling campaigns are expected to be briefed to investors by Q3.
Expect to see:
- Increased M&A Activity: Rio Tinto may look to acquire high-quality junior projects that have already cleared the preliminary economic assessment (PEA) stage but lack the capital for full-scale development.
- Partnerships with Automakers: Just as we saw with Trafigura’s 10-year lithium deal, Rio could leverage its manganese exploration success to sign direct off-take agreements with OEMs looking to de-risk their supply chains.
- Pressure on Mid-Tiers: The entry of a titan like Rio Tinto into a relatively niche market like manganese exploration will drive up the cost of entry for smaller players and potentially squeeze their access to specialized drilling equipment and talent.
The Bottom Line
Rio Tinto’s move is a clear signal that the critical minerals race has entered a new, more aggressive phase. It is no longer enough to just have copper and lithium. The “Big Miners” are now hunting for the secondary minerals that make the energy transition possible.
The strategic calculus here isn’t subtle. With the U.S. domestic supply surge proving that the Western world can: and will: build its own supply chains, Rio Tinto is ensuring it remains the dominant force in the dirt.
The clock is already ticking. By the time the first ore from Hermosa hits the market, Rio Tinto intends to have its own pipeline ready. In the high-stakes game of global commodities, being second is just another way of saying you’re losing.
