Extraction of Iron values from Red mud

Red mud is an aluminum industry waste generated by Bayer's process. It contains around 30-50% iron oxide depending upon the quality of bauxite ore used in Bayer's process Due to its highly caustic-corrosive nature and fine particle size it is considered toxic to the surrounding. In this work, an attempt has been made to achieve a suitable concentrate for iron making It was found that the carbonation step helps in alkali recovery from red-mud in the form of dissolved sodium aluminate which can be recycled in Bayer's process. X-Ray diffraction of the carbonated residue of the red-mud system showed that the complex structure of the desilication products i.e., cancrinite and sodalite formed in Bayer's process dissociates into sodium aluminate, sodium silicate and sodium alumino silicate which improves the iron recovery. Specific pretreatment process with an incorporation of a primary magnetic beneficiation prior to reduction roasting followed by secondary magnetic beneficiation manifest optimal conditions for iron recovery and proved economical in terms of specific consumption of reductant. Carbonated red mud concentrated with magnetic separation followed by muffle furnace roasting using suitable reductant produced a 50.5% iron-rich concentrate with 70% iron recovery. This technique of iron recovery from red-mud consumes two harmful industrial wastes and shows promising results. (C) 2018 Elsevier Ltd. All rights reserved.