The evolution of ironmaking process based on coal-containing iron ore agglomerates

Fundamentals of kinetics and mechanisms of iron oxide reduction of indurated pellets by reducing gases and of coal-containing iron ore composites, are reviewed. The gaseous products of the latter can be used to protect sponge iron from re-oxidation by a fully oxidized flame, provided the bed height of coal-containing iron ore agglomerates and the flame temperature are sufficiently high. Potential operational problems in RHF (Rotary Hearth Furnace) for tall beds and high flame temperature are discussed and a new hearth furnace, the Paired Straight Hearth (PSH) Furnace, is proposed.