The Electric Arc Furnace - EAF
The Electric Arc Furnace (EAF) Steelmaking Process uses steel scrap as the primary feedstock to produce more than 26% of the 1.66 billion metric tons of steel produced worldwide annually.
The EAF heats the charged scrap material by means of an electric arc and its main advantage is an improved efficiency compared to a blast furnace. The EAF does not require large quantities of combustion fuel or the addition of coke to achieve high purity steel. This allows steel to be made from 100% scrap - which is less energy intensive.
Zinc-coated galvanized scrap steel is the primary feedstock for EAF steel production.
The high temperatures necessary to melt the scrap steel generates a dust by-product - a flue dust called EAF Dust.
EAF Dust is classified by the EPA as a hazardous waste by-product. Global production of EAF Dust exceeds 7.5 million metric tons per annum.
EAF Dust may contain heavy metals including manganese, cadmium, iron, zinc, chrome, nickel and lead. Historically EAF Dust was landfilled but increased costs, government regulation and environmental issues, including ground water contamination, has necessitated alternative disposal solutions.
EAF Dust constituents such as iron and zinc, if separated, can be valuable recyclable components.
The EAF Dust generated by steel mills is predominantly recycled using the Waelz Kiln Process route.