PRESSURE FILTRATION OF BAUXITE RESIDUE FOR DRY STACKING

Hawkey, A., Kaswalder, F., Cavalli, D.

The first section of the paper presents and compares a range of bauxite residue materials from alumina refineries around the world. The physical and chemical characteristics of the materials in slurry form are compared. The results of filtration tests on the different materials is also presented and discussed, with particular regard to the moisture content and yield stress of the filter cake, and its suitability for dry stacking.

The second section of the paper consists of a number of case studies using information from some of the larger residue dewatering and dry stacking projects Diemme Filtration (A brand of Aqseptence Group) has been associated with. Test and operating data from each site is included as well as numerous images which illustrate the components of the filtration and stacking systems.

The main aim of the paper is to demonstrate the alumina industry’s adoption of this recent technology for greenfield sites as well as retrofitting the technology to existing operations with the aim of reducing the footprint of the storage area and minimising the risks associated with residue storage.