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What is the difference between a blast furnace and an electric arc furnace (EAF)?

The main distinction is between the raw materials that are used, the energy consumption and the different levels of greenhouse gas emissions. In blast furnaces, iron ore extracted from mines is used, whereas in electric furnaces, ferrous materials are recycled.

In the blast furnace (LF) steelmaking process, a chemical redox reaction is generated. Iron ore and coking coal, mixed with other materials, are loaded into the blast furnace. After a sufficient period of heating – the temperature inside a blast furnace can reach 2,000°C – cast iron is formed, which is then refined into molten steel in oxygen converters. This material is then moulded in the continuous casting process or it is forged in ingot moulds.

In the steel production process using an electric arc furnace (EAF), the raw materials are recycled ferrous metals, which are melted in a furnace at a temperature of approximately 1,600 °C, as a result of the heat released by an electric arc generated by three graphite electrodes together with the scrap metal material on the bottom of the furnace. The resulting molten steel is then subjected to a refining phase before being transferred to the continuous casting machine that transforms the material into billets.

Electric furnaces for greener and more efficient steel production

Blast furnaces are large industrial installations that, after start-up, operate continuously and cannot be easily shut down. This operational continuity is necessary to maintain the temperature and chemical reactivity inside the furnace, which guarantees stable and efficient production. On the other hand, electric furnaces are a more agile and versatile solution for steel production. They are smaller in size than blast furnaces and can be started and stopped more quickly.

Energy and sustainability

In addition, electric arc furnaces also provide significant environmental and energy efficiency benefits. Compared to the blast furnace, an electric arc furnace achieves high energy savings. Additionally, the emissions produced during the process in electric arc furnaces are considerably lower, making this technology a more sustainable choice that is compatible with the targets of environmental protection and emissions control measures for the steelmaking industry.

Some facts and figures for a better insight

According to the report published by the International Energy Agency (IEA) report, the 2020 Iron and Steel Technology Roadmap, the energy intensity required to produce 1 tonne of steel with an electric furnace is one-tenth of what is required to produce the same amount of steel with a blast furnace. If the atmospheric emissions of CO are calculated, this is seven times less with electric arc furnaces compared to producing a tonne of steel with a blast furnace.

At the Pittini Group we produce steel using the electric arc furnace, the most sustainable technology for this type of process.

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