Use of two filtration stages for bauxite residue

Abstract

Optimizing bauxite residue disposal is a goal for most alumina refineries. Cost reduction, increased disposal area lifetime, and a more sustainable operation are some of the targeted objectives. In light of these objectives, the adoption of a dry disposal system using filter press has become a very reliable solution in the last few years. However, there are different options to apply this system in plants that already has drum filters: replacing the existing ones or combine new and existing filters. CBA’s (Companhia Brasileira de Alumínio) alumina refinery designed a system with two stages of filtration (using existing drum filters and installing new filters press) to dispose bauxite residue into the operational disposal area. This paper describes the methodology, pilot tests and operations of the filter press installed in the plant.