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Hot Briquetted Iron (HBI): Enhancing Safety and Productivity in Low-Carbon Steel Production
July 8, 2025
Hot Briquetted Iron (HBI) is a compressed form of Direct Reduced Iron (DRI) that offers a flexible feedstock for iron and steelmaking and a safer and more stable product capable of being transported safely on longer ocean routes.
This compacted form of DRI is less porous than standard DRI, making it less prone to oxidation and, therefore, reduces safety concerns for handling, storing, and transporting. Its closely defined, consistent chemical and physical properties also make it a high-quality, low-emissions solution for a variety of steelmaking processes.
How is HBI made?
Direct Reduced Iron (DRI) is produced by removing chemically bound oxygen from iron oxide pellets or lump ores without melting them. Iron oxide is fed into a shaft furnace, exposing it to a hot reducing gas composed of hydrogen (H₂) and carbon monoxide (CO). This gas mixture reacts with the iron oxide, extracting the oxygen and leaving behind high-purity metallic iron in a solid, yet porous form. The resulting DRI can then be utilized as a feedstock in Electric Arc Furnaces (EAFs) or Basic Oxygen Furnaces (BOFs) to produce steel.
However, HBI goes one step further by compressing hot DRI straight after the reduction process to make it more stable and to reduce the risk of oxidation during transport. In addition, HBI allows an increase in productivity in blast furnace ironmaking because the HBI is already chemically reduced.
US-headquartered global iron and steel technology and services company Midrex perfected the HBI production method through the MIDREX® Direct Reduction Process, while German company Koppern supplies the briquetting equipment that turns hot DRI into HBI.
Why HBI is Well Suited for Low-Carbon Emissions Steelmaking
HBI is experiencing increased demand in the iron and steelmaking industry because it’s a clean, flexible and scalable source of iron for steelmakers. HBI’s advantages include:
Hydrogen-ready: HBI can be produced using 100% hydrogen as a reducing gas, allowing for near-zero CO₂ emissions when paired with renewable energy to produce the hydrogen through electrolysis (splitting water into hydrogen and oxygen).
Perfect for EAFs: HBI is highly suited to producing steel using Electric Arc Furnaces (EAFs). These furnaces use electrodes to create a high-voltage electrical arc with an extremely high temperature to melt scrap metal or iron-rich feedstock materials. Using HBI in an EAF allows steelmakers to improve the quality of the finished product, reduce reliance on scrap, and maintain process consistency.
Well-suited for blast furnaces: HBI also fulfils an important role as a flexible feedstock, well suited to different steel production processes. Integrated steelmakers can add HBI to the charge in blast furnaces to cut coke consumption and CO₂ emissions without fully transitioning to EAFs.
Easy to handle: Unlike standard DRI, HBI is significantly less reactive, making it stable enough for global transport and storage. This makes it a great option for steelmakers looking for consistent, high-quality feedstock. HBI is approximately 100 times more resistant to reoxidation than conventional DRI and picks up 75% less water.
Efficiency: HBI is less prone to yield losses during transportation, minimizing financial costs.
What’s Driving HBI Demand?
Now that we’ve looked at the inherent advantages of HBI, which external factors are driving demand? Iron and steelmakers are looking at HBI more seriously for several reasons:
- EAF steelmaking is increasing: HBI’s suitability for use in EAFs increases demand.
- Environmental regulation: Carbon pricing policies like the EU Emissions Trading System (EU ETS), the EU’s Carbon Border Adjustment Mechanism (CBAM) and similar initiatives elsewhere are making lower-CO₂ emissions feedstocks more attractive as a way to avoid or reduce exposure to these higher regulatory costs.
- Flexibility: As a scrap supplement, HBI allows steelmakers to use more scrap, or lower quality scrap while still meeting steel quality requirements.
- Consumer demand: Customers in downstream industries such as automotive, construction and energy generation are increasingly asking for greener steel, driving demand for HBI as a way to produce lower CO₂-emissions steel.
Greener processes and materials like HBI can therefore offer iron and steelmakers a route through to decarbonization while affording flexibility across multiple iron and steel production methods.
Where HBI Fits Best: Which Iron and Steelmakers Benefit the Most?
HBI’s flexibility as a feedstock makes it well-suited for various users in the iron and steelmaking industry. Here’s who stands to gain the most from the use of HBI in their process:
EAF-based steelmakers (scrap-focused mills): HBI helps when scrap quality fluctuates, ensuring a steady supply of high purity iron. HBI can supplement the use of scrap, allowing steelmakers to use more scrap, or to use lower quality scrap without compromising steel quality requirements. HBI is also ideal for steelmakers producing high-strength or speciality steels, where lower residuals and higher consistency are crucial. HBI also enables the transition to fossil-free steel when paired with renewable-energy-powered EAFs.
Integrated Steelmakers (Blast Furnace/Basic Oxygen Furnace Operations): HBI can be added to blast furnaces, reducing coke consumption and CO₂ emissions without requiring a full transition away from the BF/BOF route. It also provides a low-carbon emissions alternative to sinter and lump iron ore, helping to reduce the carbon intensity of existing BF operations.
Steelmakers in regulated carbon markets: Legally binding carbon markets operate in the EU, UK, Switzerland, US, Mexico, Canada, South Korea, Japan, Australia, and many other countries. This can impose a significant cost on CO₂ emissions from heavy industry. HBI provides a low-carbon iron source. Depending on the specific rules in each region, HBI can potentially help iron and steel companies cut their CO₂ emissions and reduce their financial obligations under compliance carbon markets.
Regions Lacking High-Quality Scrap or Iron Ore: Steelmakers in countries with poorly developed scrap supply chains can benefit from HBI’s stable quality and availability. HBI is ideal for locations where local scrap is expensive or low-quality.
Midrex’s Role in Scaling Up HBI Production
MIDREX has extensive experience developing HBI plants around the world, the first of which was the Antara plant on Labuan Island off the northeast coast of Malaysia, commissioned in 1984. The facility manufactures HBI with a metallization rate of 93-94%. Labuan has a deep water port, allowing the site to ship production to overseas clients.
In 2024, MIDREX Plants produced 76 million metric tons (Mt) of direct reduced iron (DRI), accounting for approximately 80% of global DRI production by shaft furnaces. Notably, MIDREX Plants have cumulatively produced over 1.39 billion tons of all forms of DRI, including cold DRI (CDRI), hot DRI (HDRI), and HBI, through the end of 2023.
HBI plants utilizing MIDREX technology are strategically positioned in key steel-producing regions to support global decarbonization efforts. There are 15 Midrex plants capable of producing HBI, compared with just a handful of plants operating alternative HBI production processes. The flexibility of the MIDREX Process allows plants to transition from natural gas to hydrogen over time, offering steelmakers a practical route to low CO₂ emissions production as hydrogen becomes more available and affordable.
The increasing adoption of MIDREX technology underscores its pivotal role in scaling up HBI production and facilitating the steel industry’s transition toward more sustainable practices.
The Future of HBI in Green Steel
Expect to see more HBI plants springing up worldwide as steelmakers seek a reliable, high-quality, low-carbon emissions feedstock. HBI plants will be located in regions where production economics are most favorable to supply a reliable merchant source of this feedstock.
Iron and steel companies don’t need to overhaul their whole process overnight. HBI provides an adaptable and dependable feedstock for Electric Arc Furnaces, Blast Furnaces, and hybrid models alike. As a transition to greener steel unfolds at different speeds in different locations, iron and steelmakers can rest assured that technologies are available from Midrex that can future-proof their operations, and be tailored to their individual needs.
Sources:
Midrex: Hot Briquetted Iron (HBI), Steel’s Most Versatile Metallic: Part 1 – Midrex Technologies, Inc.
Global Energy Monitor: Pedal to the Metal ’22: It’s Not too Late to Abate Emissions From the Global Iron & Steel Sector – Global Energy Monitor
Transitionzero.org: Analysing stranded asset and carbon pricing risk in steel sector
International Energy Agency (IEA): Iron and Steel Technology Roadmap – Analysis – IEA