Sustainable Recycling Technologies for Bauxite Residue (Red Mud) Utilization

Abstract

In alumina production or alumina refining, bauxite is converted to alumina (aluminium oxide) using the Bayer Process. Throughout the entire history of alumina production there has been a desire to utilize the bauxite residue created in the Bayer process with either by recovering additional products from it or using it. The red mud applications falls into several categories such as rare earths recovery, manufactured construction materials (cement, bricks, tiles, aggregate blocks and wood substitute) and bulk impermeable material for covering landfill. Considerable effort has been expended in finding applications for bauxite residue but a number of key factors affect the feasibility and economics of its adoption. The use of the carbonation can be an advantageous solution for overcoming problems associated with red mud storage and the emissions of several thousand tons of CO₂ from aluminium manufacturers each year. The key utilization of bauxite residue or red mud is to prepare “Calcium Sulfoaluminate (CSA) (Green cement)”.