Frederik Esterhuizen (FE): ABB is a global technology leader with more than 130 years of history across industries, providing everything from the smallest electrical components to large motors and drives, powering mines, trains, paper mills and even cruise ships. In the metals industry, ABB leads the way in electrification and automation for our customers, enabling a more sustainable and resource efficient future. The company’s solutions, incorporating specific metallurgy products and digital, connect engineering know how and software to optimize how things are manufactured, moved, powered, and operated.
Zaeim Mehraban (ZM): ABB has been a leading supplier and a trusted partner to the metals industry for many decades, collaborating with steelmakers, producers, original equipment manufacturers (OEMs) and other suppliers to develop customer-specific solutions to increase productivity, efficiencies, quality, and safety, while also driving the transition towards more autonomous plants.
ZM: The electric arc furnace (EAF) is expected to play a significant role in the future of the steel industry due to its flexibility, lower carbon emissions, resource efficiency, adaptability, and recycling capabilities. As the industry continues to pursue sustainable and low-carbon steel production, EAF technology will continue to evolve and contribute to the advancement of the steelmaking processes. EAFs offer more possibilities when compared with traditional blast furnaces. They can efficiently process a wide range of raw materials, including scrap steel, direct reduced iron (DRI), and hot metal, allowing for a more diverse feedstock. This enables steel producers to respond quickly to market demands and changing availability of raw materials. Crucially, they have a lower carbon footprint compared to blast furnaces and can be powered by renewable energy sources, further reducing their environmental impact and contributing to the transition towards green steelmaking. EAFs can serve as a platform for integrating emerging technologies and processes in steelmaking. As the industry progresses towards carbon neutral steel production, they can be modified and optimized to accommodate innovations such as direct electrolysis, carbon capture and storage, and other breakthrough technologies. This adaptability positions EAFs as a key component in the steel industry’s transition towards a more sustainable future.
FE: There is traditionally a lot of carbon in the steelmaking process, which is where the EAF comes in. It reduces the carbon content significantly. Customers are also testing their electrical furnaces with different configurations, beyond standard methods, to help achieve sustainability targets around the globe. Movement towards electric options vary depending on geographical region and legislative objectives set, but meeting sustainability targets is in the minds of industry operators and management teams.
ZM: Electromagnetic stirring (EMS) is not a new technology: it was first patented by ABB about 80 years ago, but it has evolved. Electromagnetic stirrers play a significant role in the operation of an EAF by improving the mixing and homogenization of the molten metal. The primary function is to induce fluid flow and agitation within the metal bath. By generating a magnetic field that interacts with the conductive molten metal, EMS promotes circulation to homogenize the temperature and composition and ensure more uniform steel. The stirring effect created by EMS enhances heat transfer within the molten metal. This improved heat transfer allows for faster melting of scrap steel and other raw materials in the EAF, leading to increased productivity and shorter processing times. It also aids in maintaining a consistent and uniform temperature within the furnace. The agitation provided by EMS facilitates chemical reactions between slag and metal while also improving the mixing of additives and alloying materials. By this way EMS enhances iron yield and solves the bottom skull problem.
The improved heat transfer and mixing effect of EMS, ensure the rapid homogenization of temperature and composition throughout the molten metal bath. This uniformity allows for more precise, efficient control of the steelmaking process, resulting in a more consistent and repeatable process. By fulfilling these roles, EMS contributes to the overall efficiency, quality, and consistency of steel production in an EAF. It helps steelmakers achieve better control of the EAF processes, improve efficiency and productivity. According to our research, typical benefits based on 160+ ArcSave electromagnetic stirrer installations worldwide include 5-7% increase in productivity, 3-5% reduction in energy consumption and related carbon emissions, up to 1% higher yield and lower use of alloys, lime and other process additions.
ZM: EMS helps reduce the environmental impact of steel production by improving energy efficiency and reducing carbon emissions. The enhanced mixing and heat transfer facilitated by EMS can lead to shorter processing times and lower energy consumption. Use of alloys, other process additions as well as electrodes and refractory materials is also reduced using EMS, further contributed to resource efficiency and lowering overall environmental impact. Additionally, when combined with the use of renewable energy sources, EMS contributes to the reduction of greenhouse gas emissions and helps achieve sustainable steel production. EAF-EMS has a measurable impact on furnace productivity. At Steel Dynamics, for example, productivity increased by 6%; at Outokumpu Stainless by 6-8%; and at SeAH, the increase was 5-7%. There is also an increase in yield, typically by about 1%. The agitation and improved heat transfer provided by EMS result in faster melting of scrap steel and other raw materials in the EAF. This leads to increased productivity, shorter processing times, and higher overall efficiency in steelmaking operations. EMS ensures the homogenization of temperature and composition throughout the molten metal bath. This uniformity allows for more precise control over the steelmaking process, resulting in consistent and high-quality steel products.
The faster melting and processing enabled by EMS contribute to higher production rates and increased throughput. This enhanced productivity can positively impact the economics of steel production by reducing costs per ton of steel produced. Steelmakers with EAF-EMS are able to maintain greater control of costs. Critically, energy costs are reduced, as power-on time is shorter and complete melting is achieved more efficiently. Energy consumption fell by 5% at Steel Dynamics, and by 3-4% at both Outokumpu Stainless and SeAH. These energy savings are inclusive of the energy used by the stirrer, which is roughly 2-3kWh per tonne of liquid steel. The use of EMS can improve safety in steelmaking operations. By enhancing the mixing of the molten metal, EMS reduces the likelihood of stratification, which can lead to localized overheating and potential accidents.