National University of Science and Technology «MISiS» (Moscow, Russia):

Hassan A. I., Post-Graduate, the Chair «Metallurgy of Steel and Ferroalloys»; e-mail: discover3030@gmail.com
Kotelnikov G. I., Cand. Eng., Ass. Prof., the Chair «Metallurgy of Steel and Ferroalloys»; e-mail: gikotelnikov@yandex.ru
Semin A. E., Dr. Eng., Prof., the Chair «Metallurgy of Steel and Ferroalloys»; e-mail: asemin2007@yandex.ru

EZZ Flat Steel (Suez, Egypt):

Megahed G. M., Deputy General Director on Technical Aff airs; e-mail: gmegahed@ezzsteel.com

The world products of direct reduced iron are presented not only by metalized pellets (DRI) and hot briquetted iron (HBI) with low phosphorus content, but also by these products with high phosphorus concentrations, depending upon the quality of iron ore and its degree of enrichment. They may contain up to 0.08% of phosphorus and above it. This makes it necessary to analyze the process of dephosphorization during the melting and refining processes of these products as a charge materials in the electric arc furnace steel making. The experiments have been conducted at EZZ Flat Steel Company in Suez, Egypt, with annual production capacity 1.2 mln. t of hot-rolled steel sheet with thickness 1.0–12.0 mm. This analysis showed that, the dephosphorization reactions are sufficiently far from equilibrium, and the continuous feeding of metallized pellets (DRI) and hot briquetted iron (HBI) hinders the dephosphorization process and decreases the distribution of phosphorous between slag and metal. For efficient dephosphorization with using the metallized materials, which have phosphorus content 0.061%, the slag should have 25–30% FeO, 4% MgO, and the slag basicity preferably should be between 2.5 and 3.0, while its temperature — 1625–1635 ^oC.

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