Riley, TC, Reid, D & Utting, L 2015, 'Polymer-modified tailings deposition – ongoing testing and potential storage efficiency opportunities', in R Jewell & AB Fourie (eds), Paste 2015: Proceedings of the 18th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 139-152, https://doi.org/10.36487/ACG_rep/1504_09_Riley
(https://papers.acg.uwa.edu.au/p/1504_09_Riley/)
Abstract: An emerging technology, known by various names such as in-line flocculation, polymer modified tailings deposition or more commercially as enhanced tailings disposal (ETD), is the subject of growing interest from mining operations. Business drivers for the mine tailings facility owners can include a variety of site-specific, material-dependant operational challenges, as well as more general desires to improve efficiency at tailings storage facilities (TSFs).

Polymers can modify the behaviour of tailings in a variety of ways; one of these is through rheological adjustment. This can often result in a steepened beach which, with careful design and use of natural or man-made landforms, can result in the potential for significant reduction in the volume of initial embankment construction material. These opportunities are the subject of a number of ongoing large-scale operational trials that are likely to become the topic of future papers.

Other material behavioural changes are inextricably linked with the technology. These include reduced segregation, improved water release, less long-term settlement, and improving permeability and subsequent consolidation behaviour. Thorough understanding of these improvements can allow for appropriate design and operational management, which can then allow the operator leverage to improve long-term operational performance.

This paper describes some scoping-level testing that focused on potential time-related opportunities that may lead to more efficient tailings management. Subject to site-specific constraints, there may be a cost-effective opportunity to defer future capital expenditure required for construction of a subsequent facility, or construction of the next raise of the embankments. Increased consolidation rates may also lead to improved trafficability and thus more efficient rehabilitation. Whilst not going into specific detail concerning operational or construction costs, this paper presents high-level results of testing and consolidation modelling, demonstrating a combination of opportunities for improved tailings performance through the implementation of the following:

Accelerating and increasing overall water release.

Improving the rate of consolidation.

Reducing the rate of rise.

Reducing the amount of post depositional settlement.

The implications of the data and modelling are discussed in the context of potential business opportunities, which can be broadly described as the ‘time value of volume’.