Bauxite, red mud and tailings dewatering by Hi-Bar filtration

摘要

In the last years the capacity of alumina plants steadily increased leading to high capacity alumina refineries with annual production rates up to 3 Mt/y and even more. Consequently, requirements on filtration technologies increased and modern filtration technologies of advanced process and plant design are necessary to meet these requirements. New filtration tasks arise such as filtration of pipelined bauxite requiring new filtration solutions. On the other side requirements on the treatment of residues like red mud increase and actual methods of filtration, washing and dewatering do not produce bauxite residue which meets future demands. The Hi-Bar Filtration and the patented Hi-Bar Steam Pressure Filtration is an advanced filtration process developed by BOKELA based on the continuous pressure filtration process. This version of the continuous pressure filtration is already applied in the chemical industry/and has shown its capability to produce a really dry, clean and easy to handle sandy bauxite residue material in an economic way. The continuous pressure filtration or hyperbaric filtration is also the chosen technology for the dewatering of pipelined bauxite at the Barcarena alumina refinery of Alunorte (Alumina do Norte do Brasil S/A) in Brazil.