Wisdom, T, Jacobs, M & Chaponnel, J 2018, 'GeoWasteTM – continuous comingled tailings for large‑scale mines', in RJ Jewell & AB Fourie (eds), Proceedings of the 21st International Seminar on Paste and Thickened Tailings
, Australian Centre for Geomechanics, Perth, pp. 465-472.
Comingled waste disposal has been used successfully at small-scale mine sites but requires bulldozers, excavators, trucks, high-cost liquid–solid separation, and significant manpower to produce a suitable mixture. Comingling is too costly for large, low value per tonne orebodies and their associated mines. GoldCorp and FLSmidth have collaborated to develop a method of comingling concentrator tailings, named EcoTailsTM, with mine waste in a continuous process to produce a stable deposit named GeoWasteTM. GeoWaste will have a placed cost that will be competitive with traditional tailings disposal methods.
GeoWaste is produced by continuously mixing filtered concentrator tailings with crushed waste rock.
The filtered tailings cost is minimised by using ‘fast filtering’ and using a nominal amount of waste rock to provide additional strength to the blended material. The acid rock drainage potential of the waste rock is reduced by minimising void space, thereby increasing the degree of saturation and reducing oxygen flux.
The resulting comingled GeoWaste is both geochemically and geotechnically stable. Fast filtering the concentrator tailings also allows for significant water recovery and reuse.
A pilot-scale process to determine the amount and type of continuous mixing required to produce GeoWaste is discussed in the paper. Initial results of small-scale GeoWaste test pads will be presented. Recommendations to implement a full-scale process will be discussed.
Keywords: EcoTails, GeoWaste, tailings, waste rock
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Wickland, B, Wilson, GW, Wijewickreme, D & Fredlund, D 2006, ‘Mixtures of waste rock and tailings: resistance to acid rock drainage’, Journal of the American Society of Mining and Reclamation, https://doi.org/10.21000/JASMR06022369