Eti aluminum red mud characterization and processing

Abstract

ETI Aluminum has capacity to process 541,000 tons of bauxite, produce 250,000 tons of alumina per year and generate approximately 260,000 tons of red mud. Red mud slurry is disposed at 30 % (w/w) solids and less than 3 g/L Na2O. ETI is focusing its efforts in maximizing extraction efficiency in digestion and improving decomposers yield. The red mud area is one of the most important topics that require serious study in terms of handling, recovery and environmental impact. A study has been initiated to determine red mud characterization, settling performance and separation strategies. XRF, XRD, TG/DTA, IR, SEM/EDX, BET and PSD analysis have been conducted to define red mud physical and chemical characteristics. Many settling tests have been performed to select the most suitable and economic flocculant that provides the best compaction, overflow clarity with an acceptable settling rate and enhanced rheology. Also ETI might face red mud disposal area problems in the following years. ETI has initiated a fast track program towards the improvement of the dewatering of red mud and increase disposal area life time.