Technology comparison of red mud filtration: assessment of washing and de-liquoring performance of vacuum drum filters versus filter presses

Authors: Schröder, K; Keller, D-E Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2655_43

Cite As:
Schröder, K & Keller, D-E 2026, 'Technology comparison of red mud filtration: assessment of washing and de-liquoring performance of vacuum drum filters versus filter presses', in AB Fourie, M Horta, M Oliveira & S Wilson (eds), Paste 2026: Proceedings of the 28th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 1-9, https://doi.org/10.36487/ACG_repo/2655_43



Abstract:
Bauxite residue, commonly called red mud after its colour, is the main byproduct of making alumina by the Bayer process. The quantity and quality of red mud, as well as the volume and the caustic content of the adherent liquor, differs widely in various refineries. Alongside the essentially non-soluble constituents of bauxite, such as iron and titanium minerals, red mud also contains some undissolved soluble alumina minerals and other compounds such as sodium aluminium hydrosilicates which are formed during processing. Common methods for red mud filtration include filter presses and vacuum drum filters – technologies with very different operating principles, investment costs and impacts on the end product. This paper compares these commonly used red mud filtration technologies, considering general operating principles, washing and de-liquoring efficiency, as well as the residual moisture achieved. The theoretical comparison of the operating principles and their impact on the red mud is illustrated with practical examples from both laboratory tests and operational experience. The objective of this paper is to outline the optimal approach to obtain red mud with the lowest amount of adherent liquor and the lowest concentration of solutes.

Keywords: red mud filtration, vacuum drum filter, filter press, technology comparison, vacuum filtration, hyper-baric operation, washing efficiency, de-liquoring efficiency

References: