Saeed Sheibani - Associate Professor, School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran.
Hamed Jamshidinia - Head of Melt Shop, Hormozgan Steel Company (HOSCO), Bandar Abbas, Hormozgan, Iran.

Slag in the electric arc furnace (EAF) steelmaking process is one of the important components. Carbonaceous materials are used in the steelmaking processes for a variety of reasons. In this paper, foamy slag practice is discussed in the EAF steelmaking process through anthracite replacement with calcined petroleum coke (CPC). The importance of this study is because this study was conducted on an industrial scale in the steelmaking unit of Hormozgan Steel Company (HOSCO). The differences between these carbonaceous materials are the higher fixed carbon, lower volatile matter and ash in the CPC. X-ray fluorescence (XRF) results for CaO, MgO, SiO۲ and Al۲O۳ components showed differences in the chemical composition of slags with different carbonaceous materials injection, especially for SiO۲, CaO and MgO. Basicity index for heats with anthracite injection has a lower value (۱.۰۹) than that of CPC injection (۱.۲۲). FeO analysis by wet chemistry method showed less FeO content (about ۲۴ wt.%) for the heats with CPC injection. However, the FeO content for the heat with anthracite injection was increased to about ۳۰ wt.%. The microstructural observation showed the porosities up to ۳۰۰ μm with a relatively uniform distribution is observed in the slag with CPC injection. It was concluded that the type of carbon sources, mainly for foamy slag production has a significant effect on the quality of slag in terms of composition and microstructural properties. In other words, injecting CPC with oxygen will improve the quality of the foamy slag.

Steelmaking, Slag, Electric arc furnace, Anthracite, calcined petroleum coke.