Identifying a solution to the red mud problem
The accumulation of large volumes of red mud and the associated supernatant liquor is a significant problem for alumina refinery operations as it requires a large disposal area. Furthermore, high volumes of liquor significantly reduce the lifetime of the disposal facility and may present a risk to the environment due to the challenges associated with wet material storage.
ETI trialed several different technologies in order to identify a solution that would improve the performance of its red mud dewatering process. These included deep cone thickener, vacuum filtration decanter centrifuge, and filter press technologies. The best performance in terms of cake dryness, liquor recovery rate, and capacity was achieved with the horizontal press filter technology supplied by Outotec.