Crude steel production begins with the reduction process, where the iron ore reacts with carbon sources inside the blast furnace. The blast furnace requires different types of refractory products with resistance to thermo-mechanical and thermo-chemical reactions.

How Does an Electric Arc Furnace Work?

Steelmaking processes have changed dramatically in recent years. Core drivers behind this evolution are growing steel demand and new global sustainability efforts.

Since blast furnaces consume large amounts of metallurgical coke, manufacturers increasingly seek alternative steelmaking processes.

Saint-Gobain Performance Ceramics & Refractories has supplied high-value-added solutions for the blast furnace route for decades. We are committed to helping manufacturers innovate towards reduced CO2 steelmaking processes. Part of that approach is the ceramic cup, a key element increasing blast furnace lifetime up to 15-20 years while reducing energy consumption. We are also actively involved in research and development (R&D) initiatives centered around developing differentiated offerings in the field.

By using electricity (and optionally solid fuel), the electric arc furnace is a key process in this evolution toward less CO2 emission-intensive steelmaking processes. We are deeply involved in supporting our customers through this constant and rapid transition towards more sustainable and effective processes with adapted refractory solutions.

Principles of an Electric Arc Furnace

Steel production starts with the reduction of iron ore using carbon and hydrogen sources within blast furnaces and direct reduced iron shafts (DRI), respectively. In low-CO2 emitting processes, the recycling of scrap iron, with or without the addition of sponge iron (DRI/HDRI), relies on electric arc furnace technology. This technology employs graphite electrodes to produce high-voltage electric currents, which melt the input materials locally. The temperatures reached in the electric arc furnace process exceed those needed for smelting standard steel, making electric arc furnaces suitable for processing alloy and stainless steel.
 
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Within the electric arc furnace, molten steel is refined by reacting the liquid metal with a lime-based slag for dephosphorization and undergoing decarburization steps by infusing oxygen into the bath. Impurities in the raw materials oxidize due to the infusion of dioxygen, and when combined with added chemical components, rise to the surface of the bath to form a basic slag. The upper section of the electric arc furnace is typically constructed with water-cooled panels. Metallurgists use slag splashes to coat these panels, forming a protective layer. In contrast, the lower section of the electric arc furnace consists of multiple layers of refractory materials designed to withstand thermomechanical and thermochemical reactions.

Refractory wear sources in EAF

Refractory materials are essential to electric arc furnace operation. They act as the containment system for liquid steel, reaching temperatures up to 1500°C.

If well-designed, refractories ensure chemical, mechanical, and thermal stability to protect the vessel's integrity over time.

The type of refractory lining considered in an electric arc furnace per area depends on the corresponding loading conditions. Major wear processes involved in EAF operations are:

  • Erosion due to scrap charging
  • Corrosion by oxidizing basic slags
  • Oxidation by atmosphere and burners
  • Thermal shock (arc radiation generating hot spots) and cycling
  • Hydration from potential leakage of water-cooled panels.
Saint-Gobain Refractory Solutions for Electric Arc Furnaces

With decades of hands-on expertise leveraging high-performance refractories throughout manufacturing lines, Saint-Gobain Performance Refractories & Ceramics provides different qualities of refractories to help match the expected type of wear in the long term.

We design, manufacture, and distribute materials and solutions that are key ingredients for the future of the steelmaking industry. They offer practicality, performance and safety while meeting the challenges of durability, resource efficiency and climate change.