Fränkle, B & Bragin, G 2025, 'What happens inside a filter press during tailings filtration', in AB Fourie, A Copeland, V Daigle & C MacRobert (eds), Paste 2025: Proceedings of the 27th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 181-190, https://doi.org/10.36487/ACG_repo/2555_12 (https://papers.acg.uwa.edu.au/p/2555_12_Frankle/) Abstract: Due to the increasing importance of filtering and stacking tailings, the number of filter presses being used is rapidly increasing. However, to ensure that this process step does not affect the overall throughput of the plant, a deep understanding of the filtration sub-steps and optimisation is necessary. Monitoring cake water content during filtration allows visualisation of different filtration behaviours and facilitates enhancement. This study investigated the filtration characteristics of coarse-grained feldspar using a laboratory filter press and a filter plate-integrated sensor, and compared them to fine-grained kaolin data. Furthermore, copper tailings particles were tested. It became apparent that larger particles experience a significant reduction in dewatering kinetics once the transition from cake build-up to cake consolidation occurs. This behaviour was also pronounced when examining copper tailings. Building on that, a theoretical approach for increasing throughput by timely switching to the subsequent process sub-step is presented. Keywords: filtration, digitalisation, sensor, filter press, filter plate