Roux, RN & Lötter , PF 2026, 'Closing the loop on iron ore tailings: a case study on 
value recovery, water reticulation and tailings storage facility footprint ', 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. 1-13, https://doi.org/10.36487/ACG_repo/2655_11
(https://papers.acg.uwa.edu.au/p/2655_11_Roux/)
Abstract: Iron ore is a bulk commodity and a major contributor to tailings. Historically, mine owners could prioritise the recovery of high-grade material leading to the deposition of tailings that can now be considered as economically recoverable. This case study examines such an opportunity at a mine in an arid region of South Africa that adopted an environmental, social and governance (ESG)-driven approach to tailings. In addition to pursuing value recovery during tailings reprocessing, alternative water recovery options were tested to assess the feasibility of transitioning to a water-efficient tailings storage facility. Laboratory and pilot-scale test work evaluated several dewatering options with pressure filtration appearing most promising yet ultimately delivering questionable benefits. The potential ESG gains from tailings reprocessing were explored (e.g. tailings volume reduction via iron recovery) alongside the practical technical and economic barriers. One of the major outcomes is that pressure filtration achieved ≈86% m/m (solids or ≈14 wt% moisture). At this moisture level, the cake remained ‘sticky’, and the flow moisture point (±12.5 wt% moisture) and the transportable moisture limit (TML) (±11.3 wt% moisture) were not achieved. Based on the material properties, the inability of pressure filtration to achieve the TML complicates material handling and ultimately the tailings transportation and final placement. A trade-off between this complexity and the additional water recovery should be closely considered on a case-by-case basis.

Keywords: dewatering, paste, filtration, tailings, ESG, transportable moisture limit, flow moisture point