Single-step Steelmaking Technology for Cheaper and Sustainable Steel
Steel has shaped civilisation for over three centuries, yet the process of making it has barely budged. Despite its critical role in everything from construction and transport to clean energy and defence, steelmaking remains notoriously energy-intensive and emissions-heavy. But a quiet revolution is underway in Conroe, Texas, where Hertha Metals has developed a single-step steelmaking technology that’s not only cheaper and more energy-efficient, but ready to scale domestically. And it couldn’t come at a better time.
Hertha’s breakthrough method converts low-grade iron ore directly into either molten steel or high-purity iron without the traditional multi-step, coal-heavy process. It’s a game-changer, especially in a geopolitical landscape dominated by supply chain risks and surging demand for rare earth elements.
As Hertha founder and CEO Dr. Laureen Meroueh put it: “We’re not just reinventing steelmaking; we’re redefining what’s possible in materials, manufacturing, and national resilience.”
A Critical Need for Homegrown Steel and Iron
The numbers paint a stark picture. The United States still imports 25% of its finished steel and over 90% of its high-purity iron — most of it from China. And while recycling accounts for over 60% of domestic steel production, scrap is a finite resource. It simply won’t meet the growing demand for high-performance, low-impurity grades.
To meet that demand, virgin steel made from iron ore remains indispensable. But traditional methods are a costly liability. Coal-based steel production accounts for nearly 10% of global industrial carbon emissions, and new facilities take years and billions to build. It’s a bottleneck the industry can no longer afford.
One Step, Many Wins
Hertha’s patented pyrometallurgical process is designed for agility. It turns virtually any iron ore — low-grade, high-grade, fines, or even steelmaking waste like millscale — into usable molten metal in a single move.
And the benefits? There’s a long list:
- Energy savings: 30% more efficient than conventional methods
- Cost reduction: Cheaper than even Chinese production
- Lower emissions: Up to 50% reduction using natural gas; up to 98% with hydrogen
- Feedstock flexibility: Processes ores previously deemed unusable
- Modular scalability: Drop-in technology suitable for plants as small as 500,000 tonnes per year
Rajesh Swaminathan of Khosla Ventures, an early investor, explained: “Their single-step, tunable process doesn’t just materially lower cost and energy use — it fundamentally expands our capacity to produce iron and steel at scale, by unlocking a wider range of iron ore feedstocks.”
From Lab Bench to Pilot Plant in Record Time
Hertha’s technology didn’t stay on the drawing board for long. In just one year, the team scaled from lab testing to operating a continuous 1 tonne-per-day pilot plant outside Houston. Funded by a $17 million round led by Khosla Ventures, Breakthrough Energy Fellows, Pear VC and Clean Energy Ventures, the pilot validated both the technology and its capital efficiency.
That plant uses natural gas or hydrogen interchangeably — a key design feature that aligns Hertha with the push towards greener fuels without the need for future retrofits.
The next step? A full-scale production facility, slated for ground-breaking in January 2026, with an output of over 9,000 tonnes per year. Initially, the facility will focus on producing 99.97+% purity iron for the U.S. rare earth magnet market.
Securing the Magnet Supply Chain
Let’s talk magnets. NdFeB permanent magnets, which power electric vehicles, robotics, wind turbines, smartphones, and defence systems, are 70% high-purity iron by mass. Yet over 90% of that iron is sourced from abroad, primarily China.
This leaves U.S. manufacturers dangerously exposed. As Meroueh noted: “We’re committed to quickly filling a gap in domestic production.”
By establishing a reliable, scalable U.S. source of high-purity iron, Hertha aims to fortify a supply chain vulnerable to political and logistical shocks. The company is already in active talks with U.S. magnet producers and has its sights set on eventually supplying 1,600 tonnes per day of high-grade steel.
The Science Behind the Breakthrough
The heart of Hertha’s technology lies in its proprietary high-temperature process, designed by Meroueh during her time at MIT. She holds a Ph.D. in Mechanical Engineering and Materials Science and previously led a hydrogen production startup — experience that now informs the hydrogen compatibility of Hertha’s system.
Her team includes seasoned professionals from steel giants like Nucor, U.S. Steel, ArcelorMittal and Steel Dynamics, as well as aerospace and tech veterans from Airbus and Blue Origin. This unique cross-disciplinary team has brought a level of technical depth and execution speed rarely seen in traditional steelmaking circles.
Built to Fit, Built to Scale
Unlike typical steel plants that require massive capital outlays and years to construct, Hertha’s system is modular and compact. That means:
- Faster deployment
- Lower upfront costs
- No need for greenfield sites
In fact, existing mills can adopt the Hertha system without tearing down current infrastructure. This flexibility will be crucial as the industry scrambles to meet both emissions targets and growing material demand.
A Cleaner, Leaner Future for American Steel
Hertha isn’t just chasing innovation for innovation’s sake. It’s solving real-world bottlenecks that threaten the competitiveness of American manufacturing. With the push for clean energy, electric vehicles, and high-performance electronics growing by the day, the demand for specialised steels and magnetic materials is only going one way.
At the same time, pressure is mounting to reduce the industry’s climate footprint. Hertha’s dual-fuel design, which can seamlessly switch to hydrogen, offers a tangible path to near-zero emissions manufacturing — without the usual risks of first-mover disadvantage.
With plans already in motion for a 500,000 tonnes-per-year facility, Hertha Metals is looking to match the output of micro mills already operating in the U.S. That puts them in a prime position to shape the next chapter of American steel.
Steelmaking, Reimagined
Hertha Metals has pulled off what many in the industry considered a pipe dream: scalable, affordable, low-emission steel and high-purity iron, built in the U.S., using America’s own resources. It’s not just an engineering feat — it’s an industrial rebirth.
If the journey from pilot to production continues at this pace, Hertha could rewrite the rules of modern metallurgy and reposition the United States as a leader in both materials innovation and strategic manufacturing.
Or, as Meroueh summed it up: “We’re building the foundation for a more secure, sustainable, and resilient economy — one tonne at a time.”
