EMR touts EAF benefits

EMR Ltd., a scrap processing firm based in the United Kingdom, has issued an essay spelling out carbon dioxide (CO₂) and greenhouse gas (GHG) emissions reductions benefits of the scrap-fed electric arc furnace (EAF) steelmaking process.

The scrap firm writes, “The bulk of the raw materials used for steel production have traditionally come from mines all over the world, emitting significant quantities of greenhouse gases and causing environmental damage.”

EMR says blast furnace/basic oxygen furnace (BOF) steelmaking involves using “iron ore from the ground to make steel in two stages.” The iron is first extracted from the ore at a temperature of about 2,000 degrees Celsius (3,620 Fahrenheit) in a blast furnace to create liquid pig iron, the firm says.

To create a metal suitable for most applications involves pouring the liquid iron into a BOF, “where excess carbon and other impurities can be removed,” the firm writes, which also has more than 50 scrap yards in the United States.

This process uses scrap metal (approximately one part scrap to four parts liquid iron, according to EMR) to act as a coolant. “Adding recycled scrap metal also reduces the embodied carbon emissions of the final product because the process of collecting and preparing recycled metals generates much lower carbon emissions than the processes of extracting and converting iron ore with coal to make pig iron,” EMR says.

EMR says the growing EAF method, “dates back to the early 20th century.” The company says the process “is widely used in the U.S. today and is increasingly being adopted in Europe.”

EAFs can use up to 100 percent recycled steel, although often they will mix recycled steel with new iron derived from iron ore, according to EMR. “The steel industry is increasingly exploring how to use more recycled materials from suppliers like EMR because it helps to keep operational costs low, whilst also reducing their carbon footprint,” the company writes. “EAFs have a key role to play in this.”

At the next stage of the steel manufacturing process, known as secondary steelmaking, the amounts of other key metals in the material are adjusted, depending on its intended use. For example, if a customer needs easily machinable free cutting steel, adding lead can make the final steel easily machinable while adding nickel, molybdenum and other metals can deliver improved corrosion resistance or other mechanical properties.

One benefit of using EMR’s scrap metal is that we can select recycled materials which already contain these additional metals, reducing the need for virgin mined metals.

“Unlike blast furnaces, EAFs can be switched on and off with relative ease, allowing for a more flexible and profitable steel industry,” EMR says of another perceived EAF advantage. “They can also use renewable power, [which] greatly reduces their associated carbon emissions, especially when compared to blast furnace steel making, which uses coke derived from coal as the main energy source.”

EMR continues, “The trends that are making steelmakers invest in new EAFs have also led to the development of new grades of low carbon impact ‘green’ steel. Green steel has a reduced carbon footprint thanks, primarily, to its use of a high proportion of recycled metal, but also because of the way the iron ore component is converted with lower carbon emissions by using natural gas rather than coke in the direct reduced iron (DRI) process.”

Green steel benefits the customers of steel companies by helping them to meet the growing demand for low-carbon products from their end users,” the firm adds. “More and more organizations are specifying products with lower embodied carbon emissions, a trend that is only going to continue.”

Steel manufacturers also are developing “ultra-low” carbon processes for converting iron ore to liquid steel using hydrogen generated from renewable power in the DRI process, says EMR. “The carbon impact is reduced further by mixing the hydrogen-based primary iron with recycled steel scrap,” the company writes. “This approach will help the industry achieve its ultimate goal of carbon-free steel production in the coming years.”