Investigation into recovery of iron values from red mud dumps

Abstract

The waste generated during the alumina production by Bayer's process is popularly called red mud. This red mud is a rich source of iron values. Generally, the iron content in the red mud varies between 20% and 45% depending on the bauxite source. The present investigation was carried out to recover iron values from red mud. Red mud contains ultrafine particles and is highly alkaline in nature because of which it is difficult to recover the iron values from it using conventional beneficiation techniques. In the present investigation, the iron values were successfully recovered by reduction roasting followed by magnetic separation. During the process, the hematitic and goethitic iron-phase minerals present in the red mud sample are converted into magnetite and metallic irons, which are subsequently recovered using low-intensity magnetic separator. The results showed that an iron recovery of 61.85% with an iron content of 65.93% of iron concentrate could be obtained at roasting temperature of 1150 degrees C, roasting time of 60min, and magnetic field intensity of 0.18 Tesla.