Sustainability in alumina production from bauxite

Alumina (Al2O3) is the main material used for the aluminum production, which is originated from bauxite ore through hydrothermal processes. Although bauxite conversion to alumina can be done through a few competitive processes, the main commercial process is still the well-known Bayer process. This process has specific environmental challenges and in more than a century the mining and aluminum industry could not overcome them. For instance, red mud disposal that is produced in the digestion step of the bauxite is high in iron oxide and also contains a significant amount of aluminum oxide. However, there has not been successful approaches in Bayer process for preventing red mud production, and even there is not still a promising method for its consumption in other industry. In the present research work, different processes for alumina production from bauxite are studied and compared with regard to sustainability; the integrated processes, their alumina yield, energy consumption, waste materials, and so on are evaluated and discussed.