Kalumba, D & Mudenge, ST 2019, 'Review of the potential role of electrokinetics technology in tailings dewatering and minerals recovery', in AJC Paterson, AB Fourie & D Reid (eds), Proceedings of the 22nd International Conference on Paste, Thickened and Filtered Tailings
, Australian Centre for Geomechanics, Perth, pp. 259-274.
Water is employed as a cost-effective media of transporting tailings; a mixture of ground waste ore, water and chemicals used in metal extraction processes. Tailings are conveyed in pipelines from the plant to the tailings dam. From the dam, the water should be recycled back to the processing plant but herein lies the challenge. The hydraulic conductivity of fine-grained tailings is very low such that instead of draining, the water tends to accumulate in the dam. Not only does this led to pore water pressure build up which undermines the dam’s stability, but it also causes massive water losses by evaporation more so in arid regions.
Dewatering of tailings prior to disposal has emerged as a solution that can be used to conserve water by producing paste or thickened tailings. Thickened tailings have higher shear strength, lower volume and they reduce dam closure costs. Filtered tailings can also be used as underground backfill for mine cavities or transported with conveyor belts and trucks to a designated point. The main limitation is that the benefits of dewatering are mainly technical and they do not yield a direct financial return. Processes that increase mineral production are vital in mine operations. Apart from the residue of the targeted metal, most tailings contain base metals like copper, nickel and zinc. Some mines have already established systems to extract valuable minerals from tailings; these include DRDGold, Lonmin and Sibanye mines in South Africa. Dewatering systems are designed to be in close contact with tailings and if they can perform the dual function of recovering water while extracting metals, they would fully meet the demands of the mining industry.
One of the most efficient techniques which can harness both dewatering and metal extraction is electrokinetics. Electrokinetics involves the application of an electrical current to induce the flow of water from the anode to the cathode in a process called electroosmosis. Electrokinetics also induces the migration of ions in a phenomenon termed electro migration. The metal cations precipitate at the cathode where they are collected and dried. This paper evaluates the viability of using an electrokinetic system to dewater and extract metals from tailings. Introducing a mineral extracting function could well be the key to increase the usage of tailings dewatering techniques by mines.
Keywords: tailings, dewatering, metal extraction, electrokinetics, electroosmosis, electro migration
Adams, M & Lloyd, V 2008, ‘Cyanide recovery by tailings washing and stripping’, Minerals Engineering, vol. 21, issue 6, pp. 501–508.
Alfa Laval 2018, Tailings Management: Meet the Tailings Challenge with Alfa Laval’s Decanter Centrifuges, viewed 11 October 2018,
ART Engineering, 2018, Mobile Soil Washing Plant, viewed 3 November 2018,
Badv, K & Mohammadzedeh, K 2015, ‘Laboratory assessment of the electroosmotic consolidation technique for Urmia lake sediments’, Transactions of Civil Engineering, vol. 39, no. C2, pp. 485–496.
Casagrande, L 1952, ‘Electroosmotic stabilization of soils’, Journal of the Boston Society of Civil Engineers, vol. 39, no 1, pp. 51–83.
Chew, SH, Karunaratne, GP, Kuma, VM, Lim, LH, Toh, ML & Hee, AM 2004, ‘A field trial for soft clay consolidation using electrical vertical drains’, Geotextiles and Geomembranes, vol. 22, pp. 17–35.
Dermont, G, Bergeron, M, Mercier, G & Richer-Lafleche, M 2008, ‘Soil washing for metal removal: a review of physical/chemical technologies and field applications’, Journal of Hazardous Material, vol. 153, pp. 1–31.
Falagan, C, Grail, BM & Johnson, B 2017, ‘New approaches for extracting and recovering metals from mine tailings’, Minerals Engineering, vol. 106, pp. 71–78.
Fosso-Kankeu, E, Waanders, F & Botes, W 2015, ‘Recovery of base metals from mine tailings dumps collected in the vicinity of Potchefstroom: leaching assisted by complexing agent’, Proceedings of the Seventh International Conference on Latest Trends in Engineering and Technology, Institute of Electrical and Electronics Engineers, Piscataway, pp. 103–106.
Gergo, R, Kulscar, T & Kekesi, T 2012, ‘Application of HCl solution for recovering the high purity metal from tin scrap by electrorefining’, Hydrometallurgy, vol. 125–126, pp. 55–63.
Glendinning, S, Mok, CK, Kalumba, D, Rogers, CDF & Hunt, DVL 2010, ‘Design framework for electro- kinetically enhanced dewatering of sludge’, Journal of Environmental Engineering, vol. 136, pp. 417–426.
GN Solids Control 2018, Decanter Centrifuge, viewed 22 October 2018,
Gray, DH & Somogyi, E 1977, ‘Electro-osmotic dewatering with polarity reversals, Journal of Geotechnical Engineering, vol. 103, issue 1, pp. 51–54.
Guo, Y 2012, Electrokinetic Dewatering of Oil Sands Tailings, PhD thesis, The University of Western Ontario, Ontario.
Hamir, R 1997, Some Aspects and Applications of Electrically Conductive Geosynthetic Materials, PhD thesis, Newcastle University, Newcastle upon Tyne.
Horwitz, W 1939, ‘The theory of electro-kinetic phenomena’, Journal of Chemical Education, vol. 16, no. 11, pp. 519–535.
Ibchem 2018, Hall Cell, viewed 13 November 2018,
Jones, CJFP, Black-Lamont, J, Glendinning, S, Bergado, D, Eng, Fourie, AB, Liming, H, Pugh, C, Romantshuk, M, Simpanen, S & Feng ZY 2008, ‘Recent research and applications in the use of electro-kinetic geosynthetics’, Proceedings of EuroGeo4: the Fourth European Geosynthetics Conference, International Geosynthetics Society, Jupiter.
Jumari, A, Purwanto, A, Nur,A, Badiman AW, Lerian, M & Paramita, F 2018, ‘Tin recovery from tin slag using electrolysis method’, Proceedings of the 3rd International Conference on Industrial, Mechanical, Electrical, and Chemical Engineering, in A Nur, AT Wijayanta & AW Budiman (eds), AIP Publishing LLC, Melville, pp. 030011-1–030011-5.
Kalumba, D & Glendinning, S 2006a, ‘A bench scale model for developing of an integrated in-situ remediation for heavy metals using EKG electrodes’, in N Lu, LR Hoyos & L Reddi (eds), Proceedings of GeoShanghai International Conference: Advances in Unsaturated Soil, Seepage, and Environmental Geotechnics, American Society of Civil Engineers, Reston, pp. 262–270.
Kalumba, D & Glendinning, S 2006b, ‘An integrated in-situ remediation technology or heavy metal contaminated soils using EKG’, in HR Thomas (ed.), Proceedings of the Fifth International Congress on Environmental Geotechnics, vol. 1, International Society of Soil Mechanics and Geotechnical Engineering, London, pp. 180–187.
Kalumba, D, Glendinning, S, Rogers, CDF, Tryer, M & Boardman, DI 2009, ‘Dewatering of tunneling slurry wastes using electrokinetic geosynthetics’, Journal of Environmental Engineering, vol. 135, pp. 1227–1236.
Lamont-Black, J, Jones, CJFP, Glendinning, S, Huntley, DT & Fourie, AB 2007, ‘Laboratory evaluation of the potential for electrokinetic belt filter press dewatering of kimberlite slimes’, in AB Fourie & RJ Jewell (eds), Proceedings of the Tenth International Conference on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth , pp. 147–152.
Lockhart, NC 1983, ‘Electroosmotic dewatering of clays. I. Influence of voltage’, Colloids and Surfaces, vol. 6, issue 3, pp. 229–238.
Lockhart, NC 1986 ‘Electro-dewatering of fine suspensions’, Advances in Solid-Liquid Separation, pp. 241–274.
McLanahan 2019, Filter Presses, viewed 11 January 2019,
Mining Life 2013, Featured Mining Project: Bolted 31m Thickener, viewed 10 January 2019,
Ntumba, E, Malenga, E, Nheta, W & Mulaba-Bafubiandi, AF 2014, ‘Kinetic studies of nickel dissolution from ammonium jarosite precipitate in an alkaline medium’, Proceedings of the International Conference on Mining, Material and Metallurgical Engineering, International Academy of Science, Engineering and Technology, Prague, p. 114.
Oil Sands Magazine 2017, Generating Cash from Tailings: A “Green Chemistry” Approach to Extracting More Value from the Oil Sands, viewed 15 November 2018,
Pugh, RC 2002, The Application of Electrokinetic Geosynthetics to uses in the Construction Industry, PhD thesis, Newcastle University, Newcastle upon Tyne.
Qui, YJ & Sego, DC 2000,’Laboratory properties of mine tailings’, Canadian Geotechnical Journal, vol. 38, pp. 183–190.
Reuss, FF 1809, ‘Sur un nouvel effet de l'électricité galvanique’, Mémoires de la Societé Imperiale de Naturalistes de Moscou, vol. 2, pp. 327–336.
Saw, H & Villaescusa, E 2013, ‘Geotechnical properties of mine fill’, in CF Leung, SH Goh & RF Shen (eds), Proceedings of the 18th Southeast Asian Geotechnical Conference: Advances in Geotechnical Infrastructure, Geotechnical Society of Singapore, Singapore, pp. 787–792.
Shang, JQ 1997, ‘Zeta potential and electroosmotic permeability of clay soils’, Canadian Geotechnical Journal, vol. 34, pp. 627–631.
Smith, ES & Connell, DH 1979, The Role of Water in the Failure of Tailings Dams, viewed 5 October 2018,
Solomonds, SL 2018, DRDGold: South Africa’s largest tailings project kicks into first gear, viewed 20 December 2018,
Szamalek, K, Marciniak-Maliszewska B, Konopka G & Zglinicki, K 2013, ‘New potential source of rare earth elements’, Gospodarka Surowcami Mineralnymi, vol. 29, no. 4, pp 59–76.
TenCate 2019, TenCate Dewatering System Brochure, viewed 10 January 2019,
United States Environmental Protection Agency 1997, ‘Technology alternatives for the remediation of soils contaminated with As, Cd, Cr, Hg, and Pb’, Engineering Bulletin, EPA/540/S-97/500, August 1997.
Van Cauwenberghe, L 1997, Electrokinetics Technology Overview Report, TO 97-03, Ground Remediation Technologies Analysis Centre, Pittsburgh.
Veal, C, Johnston, B & Miller, S 2000, ‘The electro-osmotic dewatering (EOD) of mine tailings’, Proceedings of the Fourteenth Annual Conference of the American Filtration and Separations Society, American Filtration and Separations Society, Nashville,
White, C, Glendinning, S, Lamont-Black, J, Jones, CJFP & Taylor, T 2008, ‘The application of electrokinetic geosynthetics in the advanced conditioning and composting process of sewage sludge’, Proceedings of EuroGeo4: the Fourth European Geosynthetics Conference, International Geosynthetics Society, Jupiter.
Wiaux, JP 1990, The Recovery and Recycling of Metals Using Electrolysis, ELTECH System Corp., Geneva.
Williams, DA & Williams, DJ 2004, ‘Trends in tailings storage facility design and alternative disposal methods’, Proceedings of the Australian Centre for Minerals Extension and Research Workshop on Design and Management of Tailings Storage Facilities to Minimise Environmental Impacts During Operation and Closure, Australian Centre for Minerals Extension and Research, Brisbane, p. 28.
Xinhai Mineral Processing 2019, High Rate Thickener, viewed 9 January 2019,
Yee, S & Kaniraj, R 2010, ‘Performance of drainage well in electro-osmotic consolidation experiment’, Proceedings of the Indian Geotechnical Conference, Macmillan Publishers India Ltd.,New Delhi, pp. 503–506.