Five actions to improve the sustainability of steel

Steel is one of the world’s most sustainable materials, but decarbonizing remains a challenge.

In brief

• Steelmaking currently contributes around 8% of the world’s total carbon emissions, making decarbonization a global priority.
• Technological advances have helped reduce emissions but there are five actions that can accelerate a sustainable transition.
• A collaborative approach from industry, government and consumers can build a commercially viable green steel market.

Steel is critical to continued economic development and the backbone of global sustainable initiatives, including the energy transition. But the steel industry is also one of the world’s most energy-intensive, accounting for around 8% of global carbon dioxide emissions.

For steelmakers, reducing these emissions is critical as the global decarbonization agenda accelerates. Steelmakers that move now to improve the sustainability of operations can get ahead of evolving carbon regulations and capitalize on environmental, social and governance (ESG) metrics to gain a competitive edge.

How should steelmakers steer the transition

Over the past 50 years, advances in technology and a move from traditional blast furnaces (BFs) toward the electric arc furnace (EAF) have reduced energy use in steel production by 60%. “The continued move to EAF will drive down emissions further, but creating a genuinely sustainable industry will require broader, bolder measures from all players across the steel value chain,” said Bob Stall, EY US Mining & Metals Leader.

For steelmakers, five key actions can help guide the sustainable transition:

• Assess and adopt clean technologies, promoting a balance of risk, capital cost and quality
• Increase production of sustainable steel to capitalize on growing demand
• Improve ESG performance to meet shareholder expectations
• Embrace digitization to unlock value
• Collaborate with all stakeholders to accelerate the transition to improve output quality

Assess and adopt clean technologies

Combining short-term commercial imperatives with long-term value creation requires balancing risk, cost, quality and decarbonization. Aligning investments with cyclical gains can mitigate financial risks, as higher initial capital costs are likely to be offset by the long-term benefits of more sustainable operations and improved ESG performance.

Steelmakers may consider adopting some of these emerging technologies to reduce emissions:

1. Carbon capture

Top gas recycling can recycle up to 90% of the exhaust gas from BFs, reusing it for combustion with the remaining highly CO2-concentrated 10% able to be stored or used.2 Determining whether carbon capture is suitable may depend on overall operating costs, with technology costs still high at this stage of maturity.

2. Innovations in product mix

Moving to scrap-based EAF production will reduce emissions, but each steelmaker will need to decide whether and how to transition based on the affordability and availability of scrap and the desired quality of the end product.

A comparison of emerging and new technology production methods for greener steel

3. Hydrogen

Use of green hydrogen (generated by renewables) with direct reduced iron (DRI) and EAF is likely to be the cleanest alternative for steelmakers in the future,3 although it will be some time before hydrogen is economically feasible and scalable.

4. Alternative smelting reduction processes

Some newer commercialized smelting reduction processes can offer better emission control compared with integrated plants, but their economic viability depends on overall power consumption and use of export gases.

Increase production of sustainable steel

As companies face more pressure to reduce scope 3 emissions, demand for low-carbon supplies, including steel, is growing. In particular, automakers which use 12% of the world’s steel use, are accelerating decarbonization initiatives and seeking cleaner inputs.4 Government incentives are likely to boost demand further.

Steelmakers that produce more green products can capitalize on this demand. We already see some dominant players offering certified green steel products in a trend set to increase.

Improve ESG performance

Investors are seeking more sustainable portfolios, demanding greater ESG compliance and performance from potential investment targets. At the same time, pressure from government to decarbonize is increasing, with many countries enforcing carbon tax regimes and emission trading systems (ETSs).

Improving ESG metrics will reap benefits for steelmakers beyond compliance with regulations and stakeholder expectations. “Companies with a better ESG performance can secure project financing at a lower cost, enhance resources management, reduce operational risk and increase resiliency against future changes,” said Saurabh Bhatnagar, EY India National Mining & Metals Consulting Leader; Partner, Ernst & Young LLP. Some steelmakers are including the impact of carbon emissions when assessing the profitability of capital investments. Adopting shadow internal carbon prices can help identify sustainability inefficiencies and the potential impact of a low-carbon economy on costs.

Embrace digitization to unlock value

Many steelmakers are already digital leaders, adopting technology to improve defect recognition, process safety and quality assurance. But there is a potential to make greater use of digitization to quantify, monitor, record and assess processes to enhance sustainability performance and reporting.

Digital solutions can also help improve productivity by optimizing energy consumption, minimizing waste and controlling emissions. And blockchain offers the potential to verify the sustainability quotient of steel value chains, giving end users reliable data to assess their net carbon impact. It can also help create more agile supply chains, while cloud computing can allow central command and control centers to oversee geographically dispersed mine-to-metal value chains.  

Collaborate with all stakeholders to accelerate the transition

Decisions made around sustainability initiatives cannot be based purely on financial costs to the business. Instead, steelmakers must act with all stakeholders in mind and be prepared to make a balanced trade-off between industry, end consumers and the environment. Aligning stakeholders will be critical to quicken the pace of change needed and to enable the collaboration required to co-develop feasible solutions to complex challenges.

Building the future of green steel

The steel industry’s transition to greener steel will not be uniform across regions. Steel producers in Western regions and countries already investing in improving sustainability are likely to see a more rapid adoption of low-carbon technologies compared with steel producers in China and India, where the combination of newer capital assets and cost pressures will force a more gradual transition.

Even in countries where progress will be slower, steelmakers should make incremental investments in process improvements to decrease energy intensity, reduce carbon emissions, increase material efficiency and promote the circular economy. Given the relatively large carbon footprint of steel production, even small steps will make a big difference in moving the industry closer to carbon neutrality.

Making this shift will require a staged digital road map to realize the potential of new technologies and achieve economies of scale, while improving sustainability across the steel value chain. And it will require steelmakers to join with a broad range of stakeholders, including governments, the United Nations, academia, communities and the World Steel Association, to build a greener steel industry.

Steel is one of the world’s most sustainable materials — permanent, forever reusable and the most recycled substance on the planet. Building a more sustainable production process is a long-term investment that will yield enormous environmental benefits over the full life cycle of green steel.

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6 Steps of the Steel Manufacturing Process

Steel is known for being lightweight but strong, making it suitable for a variety of industries and applications. Next to plastic and paper, steel is one of the most common materials seen in products used in our everyday lives.

In the construction industry, steel is used in the creation of buildings and other structures for strength. Manufacturing processes, such as for cars, airplanes, and kitchen appliances, also rely on steel for production. Last but not least, steel is imperative for communication as it is used in the creation of transmission and cell phone towers.

The steel manufacturing process can be divided into six steps: Making the iron, primary steelmaking, secondary steelmaking, casting, primary forming, and secondary forming.

Step 1: Making the Iron

Steel is a metal alloy made of iron and carbon. Thus, the steel manufacturing process starts by making iron. To do this, limestone, coke, and iron ore are combined and put into a blast furnace. The elements are melted together to create a hot metal known as molten iron.

Step 2: Primary Steelmaking

The second step of the steel manufacturing process can be completed with two different pieces of equipment: a basic oxygen furnace and an electric arc furnace. With a basic oxygen furnace, the molten metal produced in step 1 is infused with scrap steel. Then, oxygen is forced through the furnace to remove the impurities in the molten iron. With an electric arc furnace, as the name suggests, electricity is forced through the furnace to purify the iron. The completion of step 2 results in raw steel.

Step 3: Secondary Steelmaking

Just like there are different grades and families of stainless steel, there are also different types of regular steel. The different grades are determined by the elements that remain in the metal at the completion of the manufacturing process. Secondary steelmaking refines the composition of the steel to create the desired grade. This is done with different techniques such as stirring and ladle injections.

Step 4: Casting

During the fourth step of steel manufacturing, molten iron is cast into molds for cooling. This process starts to set the shape of the steel and causes a thin, hard shell to form. The strands of the shell are malleable and can be worked into the desired shape of flat sheets, beams, wires, or thin strips.

Step 5: Primary Forming

Primary forming continues the shaping process. A hot roller is used to fine-tune the casting. The steel is molded into the desired shape and surface finish. Some examples include bloom, billet, and slab.

Step 6: Secondary Forming

The final step of the steel manufacturing process creates the final shape and properties of the steel. Secondary forming is accomplished with different methods such as shaping (cold rolling methods), machining (drilling), joining (welding), coating, heat treatment, and surface treatment. At the completion of step 6, the steel is fully shaped, formed, and ready for use and processing in various applications.

The harsh environment and extreme temperatures encountered in steel mills during the steel manufacturing process require high-quality equipment built to last. LMM GROUP offers a variety of products suitable for steel mills.

How Steel is Made, Step by Step

Chances are, you've already used steel in several ways today - from the car you drove in to work to the knife and fork you used at dinner. Steel is all around us and the world would look very different without it, but most of us don't really know how it's made.

Before We Start...

Steel production is a complex process that can vary based on the type of steel and the techniques used. This guide will be focusing on the most common method, basic oxygen steelmaking, but keep in mind that not all steel is processed this way - some are refined using electric arc furnaces or other methods.

Now, let's walk through how the typical process works.

1. Raw Material Extraction

The steel-making process begins with gathering the essential raw materials: iron ore, coal, and limestone.

Iron Ore: This is the main source of iron, the key element in steel. The most commonly used types are hematite and magnetite.

Coking Coal: Coking coal is used to produce the intense heat needed to reduce the iron ore into a usable form.

Limestone: Limestone removes impurities such as silica, sulphur, and phosphorus during the process.

Alloying elements like magnesium or nickel may also be gathered for use later in the refining process.

These materials are typically mined from large deposits and transported to steel mills, where the transformation into steel begins.

2. Coke Making

The next step is turning coal into coke (no, not the drink). This involves heating coal in a low-oxygen environment, usually in a coke oven, to remove volatile compounds. This leaves behind coke, a carbon-rich fuel that burns hotter and cleaner than regular coal.
Coke is crucial because it provides the intense heat needed in the blast furnace, where the iron ore will be melted down.

3. Blast Furnace

Once the coke is ready, the next step is to produce molten iron in a blast furnace - a massive structure that can reach 100 to 200 feet tall. Here's how the process works:

Iron ore, coke, and limestone are layered inside the furnace, which is lined with heat-resistant bricks.

Hot air around 1,500--2,200°C is blasted into the furnace from the bottom. This extreme heat ignites the coke to create carbon monoxide gas, which reacts with the iron ore, reducing it to molten iron.

As the iron ore melts, impurities like silica form a liquid slag that floats on top of the molten iron. The purified iron, now in liquid form, sinks to the bottom of the furnace and is tapped off.

This molten iron, known as pig iron, still contains a high level of carbon and impurities, which makes it brittle. It needs to go through a refining process to turn it into steel.

Fun fact: Pig iron got its name from the way the moulds were arranged for casting. The moulds were set up in a pattern that resembled a mother pig with her piglets. The larger mould, where the molten iron was poured, was called the "sow," and the smaller ingots that flowed from it were called "pigs"!

4. Basic Oxygen Steelmaking (BOS)

The pig iron from the blast furnace is then taken to a basic oxygen furnace to be refined into steel. This process lowers the carbon content and removes impurities, making the iron stronger and more versatile.

Molten pig iron is poured into the furnace, and pure oxygen is blown in at high pressure. The oxygen reacts with the carbon in the pig iron, creating carbon dioxide and reducing the carbon content.

Fluxes like limestone are added to help remove impurities. As the oxygen and fluxes react with the carbon and other impurities, they form slag, which is then removed.

The amount of oxygen injected, and the timing of the process are carefully adjusted to make sure the carbon content reaches the desired level for the specific type of steel being produced (e.g. 0.3% for mild steel), while preserving the steel's other essential properties.

At this stage, alloying elements like manganese, chromium, or nickel can be added to give the steel specific properties, such as increased strength or corrosion resistance. This creates different types of steel, with stainless steel being one of the most well-known.

The result is high-quality liquid steel with a much lower carbon content than the original pig iron.

5. Casting

Once refined, the molten steel is ready to be cast. The steel is poured into moulds to form slabs, billets, or blooms, depending on the desired shape.

Most modern steel plants use a method called continuous casting. In this process, the molten steel is continuously poured into a water-cooled mould, where it solidifies as it moves downward. This produces long strands of steel that are cut to the needed length. Steel might still be cast into large ingots in some cases, but this method is less common today.

6. Forming and Shaping

After the steel has solidified, it goes through additional shaping to create the final product. This is usually done through hot or cold rolling:

Hot Rolling: The steel is heated above its recrystallisation temperature and passed through large rollers to reach the desired thickness. This method is used for products like steel sheets, beams, and rails.

Cold Rolling: For some applications, the steel is rolled at room temperature. This gives the steel a smoother surface and more precise dimensions, making it ideal for products that require a high-quality finish.

7. Finishing Processes

The final step in the actual steel-making process is a series of finishing treatments that prepare the steel for use in construction, manufacturing, and other industries. These processes include:

Soaking the steel in acid (known as 'pickling') to remove surface impurities like rust or scale.

Galvanisation, which involves coating the steel with zinc to protect it from rusting.

Heat-treating the steel to improve its strength, ductility, or toughness.

Adding a protective coating or a colourful painted finish.

Cutting to meet certain specifications.

8. Quality Control and Testing

Before steel products are shipped out, they go through strict quality control tests to make sure they meet the necessary mechanical properties, chemical composition, and dimensional tolerances. Common tests include:

Tensile testing to measure the steel's strength.

Hardness testing to check its resistance to indentation.

Ultrasonic testing to detect any internal flaws or cracks.

Once the steel passes these tests and meets the standards, it's ready to be used in a wide range of products - from tools and machinery to vehicle frames, furniture, medical equipment, and just about anything else you can imagine!