Dobler, T, Lerchenmüller, N & Hahn, J 2026, 'Vacuum filters versus filter presses: rethinking technology selection for tailings dry stacking', 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. 1-7, https://doi.org/10.36487/ACG_repo/2655_40
(https://papers.acg.uwa.edu.au/p/2655_40_Dobler/)
Abstract: Tailings are an unavoidable byproduct of mineral and metal ore processing and represent a growing challenge in terms of safe and sustainable storage. One increasingly adopted solution is dry stacking, where tailings are mechanically dewatered to such an extent that they can be transported and stacked without risk of liquefaction. A residual moisture content below 15 wt.-% is commonly considered a practical threshold. For this purpose, filter presses are widely used. Operating in batch mode at pressures up to 25 bar, they can reliably achieve low residual moisture levels. However, the technology comes with significant disadvantages: high wear on filter cloths, the need for large and complex infrastructure and reliance on highly skilled operating as well as maintenance personnel – all contributing to high capital expenditures (capex) and operating expenses (opex).
A promising alternative – particularly for coarser tailings (x50 > 50 µm) – is the application of vacuum disc filters. Although the achievable residual moisture is somewhat higher due to limited pressure differentials, they offer considerable advantages in terms of capital and operational expenditures.
This paper explores the feasibility of using vacuum disc filters for dry stacking of tailings. It starts with Atterberg limit tests on different tailings materials, demonstrating that the residual moisture content required for safe stacking depends strongly on the specific material system and does not necessarily need to be in a range below 15 wt.-%. Next, a comparative assessment of filter presses and vacuum disc filters is provided, focusing on both technical performance and economic factors, illustrated with data from an industrial case study. The paper concludes by questioning the dominant role of filter presses and assessing the conditions under which vacuum filters could realistically emerge as a viable and perhaps superior alternative in modern tailings management.

Keywords: tailings filtration, tailings stacking, vacuum disc filter, filter press, residual moisture