Bridging flotation and dewatering chemistry: A review of flotation reagent effects on tailings coagulation-flocculation-sedimentation
Abstract
Closing water circuits and dry-stacking tailings are now central goals of sustainable mineral processing, and both depend on the efficient coagulation-flocculation-sedimentation (C-F-S) of flotation tailings in thickeners. Flotation reagents, namely, collectors, frothers, depressants and modifiers, are selected for their effect on valuable mineral grade and recovery, while thickener performance is optimised separately through coagulant and flocculant dosing; the two chemistries are rarely considered together. Yet flotation tailings entering a thickener are not chemically inert; many depressants and modifiers are polymeric or ionic species that resemble the coagulants and flocculants used downstream, and could plausibly enhance, suppress or otherwise alter particle destabilisation and floc growth. This review synthesises literature on flotation reagent chemistry, coagulation-flocculation theory, and the factors (pH, ionic strength/valence, dosage, zeta potential and temperature) known to govern C-F-S performance in both tailings and general water-treatment systems, in order to evaluate the plausibility and evidence base for this coupling. Findings from the literature show consistent qualitative agreement between flotation-tailings and water-treatment systems for each factor, but almost no direct evidence on residual flotation reagents themselves, a gap now beginning to be addressed by recent studies on residual coagulants, flocculants and dewatering aids re-entering flotation circuits. The review concludes with a focused set of research priorities rather than a detailed experimental protocol, aimed at establishing whether, and under what conditions, flotation reagent selection should be treated as a dewatering-relevant decision.
Document Type: Review
Cited as: Manono, M. S., Corin, K. C. Bridging flotation and dewatering chemistry: A review of flotation reagent effects on tailings coagulation-flocculation-sedimentation. Sustainable Earth Resources Communications, 2026, 2(3): 115-130. https://doi.org/10.46690/serc.2026.03.02
DOI:
https://doi.org/10.46690/serc.2026.03.02Keywords:
Flotation reagents, coagulation-flocculation-sedimentation, tailings dewatering, closed water circuits, dry stacking, thickeningReferences
Adda-Mensah, J., Yeap, K. Y., McFarlane, A. J. The influential role of pulp chemistry, flocculant structure type and shear rate on dewaterability of kaolinite and smectite clay dispersions under couette Taylor flow conditions. Powder Technology, 2007, 179(1-2): 79-83.
Arjmand, R., Massinae, M., Behnamfard, A. Improving flocculation and dewatering performance of iron tailings thickeners. Journal of Water Process Engineering, 2019, 31: 100873.
Arnold, B. J., Aplan, F. F. The effect of clay slimes on coal flotation, Part II: the role of water quality. International Journal of Mineral Processing, 1986, 17: 243-260.
Becker, M., Harris, P. J., Wiese, J. G., et al. Mineralogical characterisation of naturally floatable gangue in Merensky Reef ore flotation. International Journal of Mineral Processing, 2009, 93: 246-255.
Bernardis, F., Wallenius, S. Batch flotation cell design and testing considerations, in Mineral Processing Plant Design, Practice and Control, edited by T. Napier-Munn and B. A. Englewood Wills, Society for Mining, Metallurgy and Exploration, Littleton, Colorado, 2018.
Bournival, G., Zhang, F., Ata, S. Coal flotation in saline water: effects of electrolytes on interfaces and industrial practice. Mineral Processing and Extractive Metallurgy Review, 2021, 42: 53-73.
Bratby, J. Coagulation and Flocculation in Water and Wastewater Treatment. London, UK, IWA Publishing, 2016.
Bulatovic, S. M. Handbook of Flotation Reagents: Chemistry, Theory and Practice - Flotation of Sulphide Ores. Amsterdam, The Netherlands, Elsevier, 2007.
Bulatovic, S. M. Handbook of Flotation Reagents: Chemistry, Theory and Practice, Volume 3: Flotation of Industrial Minerals. Elsevier, 2014.
Chong, K. H. Modelling and Optimisation of a Coagulation-Flocculation Process for Industrial Wastewater Treatment. Penang, Universiti Sains Malaysia, 2012.
Corin, K. C., Reddy, A., Miyen, L., et al. The effect of ionic strength of plant water on valuable mineral and gangue recovery in a platinum bearing ore from the Merensky reef. Minerals Engineering, 2011, 24: 131-137.
Corin, K. C., Wiese, J. G. Investigating froth stability: a comparative study of ionic strength and frother dosage. Minerals Engineering, 2014, 66-68: 130-134.
Fan, Y., Ma, X., Dong, X., et al. Effect of shear-induced breakage and refocculation on the floc structure, settling, and dewatering of coal tailings. Physicochemical Problems of Mineral Processing, 2020, 56: 363-373.
Gregory, J. Particles in Water: Properties and Processes. Boca Raton, London, UK, CRC Press/IWA Publishing, 2006.
Gungoren, C., Unver, I. K., Ozdemir, O. Investigation of flocculation properties and floc structure of coal processing plant tailings in the presence of monovalent and divalent ions. Physicochemical Problems of Mineral Processing, 2020, 56(5): 747-758.
Harrison, S. T. L., Slatter-Christie, K., Broadhurst, J. L. Integrating competing water needs of mining and mineral processing with the environment, community and economic activity in a mining-dominated catchment. Presented at 11th International ICARD | IMWA | MWD Conference, Pretoria, South Africa, 10-14 September 2018.
Ikumapayi, F., Sis, H., Johansson, B. Recycling process water in sulfide flotation, Part B: effect of H₂O₂ and process water components on sphalerite flotation from complex sulfide. Minerals and Metallurgical Processing, 2012, 29: 192-198.
Ikumapayi, F. K., Johansson, B., Rao, K. H. Recycling of process water: effect of calcium and sulphate ions in sulphide flotation. Conference in Minerals Engineering, 2010: 51-61.
Johansson, G., Pugh, R. J. The influence of particle size and hydrophobicity on the stability of mineralized froths. International Journal of Mineral Processing, 1992, 34: 1-21.
King, R. P. Principles of Flotation. Johannesburg, South African Institute of Mining and Metallurgy, 1982.
Lee, C. S., Robinson, J., Chong, M. F. A review on application of flocculants in wastewater treatment. Process Safety and Environmental Protection, 2014, 92(6): 489-508.
Li, M., Zhu, X., Yang, H., et al. Treatment of potato starch wastewater by dual natural flocculants of chitosan and poly-glutamic acid. Journal of Cleaner Production, 2020, 264: 121641.
Ma, J., Wang, R., Wang, X., et al. Drinking water treatment by stepwise flocculation using polysilicate aluminum magnesium and cationic polyacrylamide. Journal of Environmental Chemical Engineering, 2019, 7(3): 103049.
Mackenzie, M., Malhotra, D., Riggs, W. Organic polymers as depressants, in Chemical Reagents in the Minerals Industry, Society for Mining, Metallurgy and Exploration, Littleton, Colorado, 1986.
Manenzhe, R. M., Manono, M. S., Wiese, J. G., et al. Exploring the effects of different process water sources on xanthate adsorption and flotation performance. Minerals Engineering, 2023, 204: 108376.
Manono, M. S. Investigating Electrolyte-Reagent-Mineral Interactions in Response to Water Quality Challenges in the Flotation of a PGM Ore. Rondebosch, University of Cape Town, 2018.
Manono, M. S., Khan, S. F., October, L. L., et al. Residual dewatering aids in process water on flotation performance of a selected Cu-Ni-PGM ore from a siliceous reef. Minerals Engineering, 2024a, 209: 108637.
Manono, M. S., Khan, S. F., October, L. L., et al. The effect of residual coagulants and flocculants in process water on the flotation performance of a selected Cu-Ni-PGM ore. Minerals Engineering, 2024b, 216: 108850.
Manono, M. S., October, L. L., Manenzhe, R. M., et al. Residual dewatering aids in process water on the depressant adsorption and zeta potential of laboratory flotation. Minerals Engineering, 2024c, 105(1): 136.
Martinovic, J., Bradshaw, D. J., Harris, P. J. Investigation of surface properties of gangue minerals in platinum bearing ores. Journal of the South African Institute of Mining and Metallurgy, 2005, 105: 349-356.
Michaux, B., Rudolph, M., Reuter, M. A. Challenges in predicting the role of water chemistry in flotation through simulation with an emphasis on the influence of electrolytes. Minerals Engineering, 2018, 125: 252-264.
Morris, G. E., Fornasiero, D., Ralston, J. Polymer depressants at the talc-water interface: adsorption isotherm, microflotation and electrokinetic studies. International Journal of Mineral Processing, 2002, 67: 211-227.
Muzenda, E. An investigation into the effect of water quality on flotation performance. World Academy of Science, Engineering and Technology. International Journal of Chemical, Molecular, Nuclear, Materials and Metallurgical Engineering, 2010, 4: 562-566.
Muzinda, I., Schreithofer, N. Water quality effects on flotation: impacts and control of residual xanthates. Minerals Engineering, 2018, 125: 34-41.
Napier-Munn, T., Wills, B. A. Wills' Mineral Processing Technology: An Introduction to the Practical Aspects of Ore Treatment and Mineral Recovery. 7th edn. Oxford, UK, Elsevier Science & Technology Books, 2006.
Nazari, B., Abdolalian, S., Taghavijeloudar, M. An environmentally friendly approach for industrial wastewater treatment and bio-adsorption of heavy metals using Pistacia soft shell (PSS) through flocculation-adsorption process. Environmental Research, 2023, 235: 116595.
Nguyen, T. P., Hankins, N. P., Hilal, N. A comparative study of the flocculation behaviour and final properties of synthetic and activated sludge in wastewater treatment. Desalination, 2007, 204(1-3): 277-295.
Nie, Y., Xin, L., Qi, C., et al. A bioflocculant from Corynebacterium glutamicum and its application in acid mine wastewater treatment. Frontiers in Bioengineering and Biotechnology, 2023, 11: 1136473.
Nonfodji, O. M., Fatombi, J. K., Ahoyo, T. A., et al. Performance of Moringa oleifera seeds protein and Moringa oleifera seeds protein-polyaluminum chloride composite coagulant in removing organic matter and antibiotic resistant bacteria from hospital wastewater. Journal of Water Process Engineering, 2020, 33: 101103.
Parekh, B. K. Advances in Flotation Technology. Littleton, Colorado, Society for Mining, Metallurgy and Exploration, 1999.
Parolis, L. A. S., van der Merwe, R., Groenmeyer, G. V., et al. The influence of metal cations on the behaviour of carboxymethyl celluloses as talc depressants. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2008, 317: 109-115.
Pearse, M. J. Historical use and future development of chemicals for solid-liquid separation in the mineral processing industry. Minerals Engineering, 2003, 16(2): 103-108.
Peng, Y., Seaman, D. The flotation of slime-fine fractions of Mt Keith pentlandite ore in de-ionised and saline water. Minerals Engineering, 2011, 24: 479-481.
Ramos, O., Castro, S., Laskowski, J. S. Copper-molybdenum ores flotation in sea water: floatability and frothability. Minerals Engineering, 2013, 53: 108-112.
Shamukuni, T. O., Manono, M. S., October, L. L., et al. Anionic Polyacrylamide and Carboxymethyl Cellulose on Flotation Performance of a Cu-Ni-PGM Ore in Degrading Water Quality. Minerals Engineering, 2025a, 228: 109307.
Shamukuni, T. O., Manono, M. S., October, L. L., et al. Calcium and sulfate Ions on flotation performance of a Cu-Ni-PGM ore in the presence of anionic polyacrylamide and carboxymethyl cellulose. Minerals Engineering, 2025b, 234: 109708.
Sharma, B. R., Dhuldhoya, N. C., Merchant, U. C. Flocculants - an ecofriendly approach. Journal of Polymers and the Environment, 2006, 14(2): 195-202.
Slatter, K. A., Plint, N. D., Cole, M., et al. Water management in Anglo Platinum process operations: effects of water quality on process operations. International Mine Water Conference Proceedings, 2009: 46-55.
Taggart, A. F. Handbook of Mineral Dressing: Ores and Industrial Minerals. New York, USA, John Wiley & Sons, 1945.
Tang, J., Zhang, Y., Bao, S. The effect of Ca²⁺ and Mg²⁺ on the dispersion and flocculation behaviour of muscovite particles. Minerals, 2016, 6(3): 93.
Vasudevan, M., Bhambhani, T., Nagaraj, D. R., et al. Impact of dissolved gangue species and fine colloidal matter in process water on flotation performance, in Water in Mineral Processing: Proceedings of the 1st International Symposium. Society for Mining, Metallurgy and Exploration, Littleton, Colorado, 2012.
van Oss, C. J. Interfacial Forces in Aqueous Media. 2nd edn. Boca Raton, Florida, CRC Press/Taylor & Francis, 2006.
Veki, A. Fundamentals of Froth Flotation Reagents. Littleton, Colorado, Society for Mining, Metallurgy and Exploration, 2013.
Wang, D. Flotation Reagents: Applied Surface Chemistry on Minerals Flotation and Energy Resources Beneficiation. Berlin: Springer, 2016.
Wiese, J. G., Harris, P. J., Bradshaw, D. J. The use of very low molecular weight polysaccharides as depressants in PGM flotation. Minerals Engineering, 2008, 21: 471-482.
Wills, B. A., Finch, J. A. Wills' Mineral Processing Technology: An Introduction to the Practical Aspects of Ore Treatment and Mineral Recovery. 8th edn. Oxford, UK, Butterworth-Heinemann/Elsevier, 2016.
Yaghoobian, S., Hasani Zonooz, M., Saeedi, M. Performance evaluation of Fe-based water treatment sludge for dewatering of iron ore tailings slurry using coagulation-flocculation process: optimization through response surface methodology. Journal of Environmental Management, 2022, 316: 115240.
Zhai, D., Feng, B., Guo, Y., et al. Settling behavior of tungsten tailings using serpentine as flocculant. Separation and Purification Technology, 2019, 224: 304-307.
Zhao, C., Yan, H., Pu, Y., et al. Preparation, performances, and mechanisms of microbial flocculants for wastewater treatment. International Journal of Environmental Research and Public Health, 2020, 17(4): 1360.
Downloads
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Malibongwe S. Manono, Kirsten C. Corin
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.