Cement-Free Agglomerates Made of Dusts and Sludges from Iron and Steel Industry—A Sustainable Way of Fe Recycling

The internal recycling of iron-rich fine residues is a crucial process for reducing the raw material loss and the carbon footprint in sustainable ironmaking and steelmaking. Traditionally, cement has been used as a binder to ensure the structural integrity of agglomerates during transport and charging. While cementitious binder can achieve the necessary structural support, it contributes significantly to the carbon footprint. This study investigated the effects of alternative biogenic binders and varying compaction pressures on the physical and mechanical properties of agglomerates produced from three different types of fine residues from steel (SR) and cast-iron (FR) production. In addition, the self-reducing capability and degree of metallization of these agglomerates were evaluated through pyrometallurgical experiments in a Tammann furnace. The resulting agglomerates exhibited sufficient mechanical strength and high iron recovery rates. These findings confirm that biogenic binders can effectively replace cementitious binders without compromising the self-reduction performance of the agglomerates.