Study the Recycling of Red Mud in Iron Ore Sintering Process

Abstract

Red mud (RM), the by-product generated during the alumina extraction process, is considered a valuable secondary raw material, since iron (20–54%) represents its major constituent. Accordingly, the suitability of recycling this RM in the sintering process of Egyptian iron ore was studied. The effect of adding different amounts of RM to the sinter charge mixture (0–10 wt.%) on the sintering process performance as well as the chemical, physical and mechanical properties of the produced sinter was investigated. The results revealed that increasing the amount of red mud in the sinter charge mixture leads to a high improvement in the strength of the produced sinter till reaching a maximum at 7% addition, which deteriorates thereafter. Meanwhile, owing to the fine nature of the red mud, increasing its contents in the sinter charge mixture leads to reduced speed of the sintering process, which consequently affects the productivity at the blast furnace yard. The sinter produced with the addition of 3% red mud shows the highest reducibility. These results indicate the suitability of recycling RM in the Egyptian iron ore sintering process with an amount not higher than 3 wt.% of the total sinter mixture charge.