Electrokinetic belt press dewatering of kimberlite tailings — case study of a full scale field trial

Authors: Lamont-Black, J; Jones, CJFP; Fourie, AB; Krüger, L Paper is not available for download Contact Us

DOI https://doi.org/10.36487/ACG_rep/1063_29_Lamont-Black

Cite As:
Lamont-Black, J, Jones, CJFP, Fourie, AB & Krüger, L 2010, 'Electrokinetic belt press dewatering of kimberlite tailings — case study of a full scale field trial', in R Jewell & AB Fourie (eds), Paste 2010: Proceedings of the Thirteenth International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 329-342, https://doi.org/10.36487/ACG_rep/1063_29_Lamont-Black



Abstract:
In the continuum of tailings dewatering, filtration is at one of a number of technologies routinely employed. Filtration rates are increased by steepening the hydraulic pressure gradient across the tailings by using vacuum and or pressure. Two common drawbacks associated with fine grained materials are (i) low hydraulic permeability such that flow rates are small and (ii) clogging and/or blinding of the filter medium e.g. a filter belt. Both effects reduce the overall dewatering rate. An alternative belt press technique is described in this paper, utilising newly developed conductive polymeric belts to produce filter belts that can be used to dewater ultrafine material using electro-osmosis. In April 2008 a full scale trial to dewater ultrafine kimberlite tailings was undertaken using an electrokinetic belt filter press. The trial successfully dewatered a stream of kimberlite paste at approximately 50% dry solids content to produce a stable solid cake at approximately 75% dry solids. The paper describes the trial and gives details of the technical and financial benefits that the electrokinetic technique offers to the treatment and disposal of paste including: significant recovery of water; significant reduction in energy usage; reduction in the volume of waste to be discarded; and a reduction in the cost of tailings waste disposal. The development of electrokinetic dewatering of tailings has other potential advantages including the elimination of the need for slimes dams in their current form and replacement by compacted landforms that pose considerably lower geotechnical and environmental risk.

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