JFET_V5_N3_A1 Suchita B. Rai Kailas L. Wasewar Journal on Future Engineering and Technology 2230 – 7184 5 3 1 8 Red mud, Utilization, Disposal, Neutralization, Review The century old technology, the Bayer process remains the most economic means of obtaining alumina from bauxite till date. Worldwide alumina is produced from bauxite by Bayer Process which generates highly alkaline solid waste (pH 11 - 13) known as Red Mud. Around 70 million tonnes of red mud per annum is generated world wide of which ~ 4 million tonne of red mud is generated annually in India. Disposal of such a huge quantity of alkaline solid waste is creating a big environmental issue leading to its alternative usage / utilization methods. Several routes of using red mud in effective ways have been tried and extensive research is still going on to find the most suitable and economic way of utilizing the same. It is an iron-rich residue which also contains undigested alumina, titania and sodium aluminosilicates Indian Red Mud mainly consists of Fe2O3(35-55 wt%), Al2O3(16-22 wt%), SiO2(4-16 wt%), Na2O(3-6 wt%), TiO2(2-19 wt%), CaO(0.8-4.5wt%) and other oxides in trace amount depending upon the mineralogy and process parameters used. Red mud is disposed as slurry having a high solid concentration of 30-60% and with a high ionic strength. It is disposed as dry or semi dry material in red mud pond or abandoned bauxite mines. The disposal of the red mud represents a major loss of valuable soda and has a high pH value as a result of the entrained soda The environmental concerns which are related to the disposal of red mud are its large quantity which consumes vast areas of land and its causticity. Problems associated with the disposal of red mud waste include its high pH (11-13), alkali seepage into underground water, safety in storage, and alkaline air borne dust impact on plant life. High iron content has also shown scope of metal / value added product recovery from the same. Many special adsorbent / compounds have been developed from red mud for pollution control purpose also. But these applications are not always economically viable because of source and surrounding conditions. So environmentally safe disposal has also been given importance; i.e. neutralization of red mud for safer disposal as well as amendment of red mud to support re-vegetation / vegetation cover in the plant and mine surrounding areas. At present, there is no viable process developed for utilising the bauxite residue, consequently this large quantity of waste material is required to be disposed economically and safely to the environment. In this paper, all different directions of red mud utilization are discussed. The paper also reviews the methods of neutralization for its safe disposal. February - April 2010 Copyright © 2010 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=1137