Reid, D, Kaminsky, HAW & Fourie, AB 2024, 'Some observations on the effects of polymer degradation on geotechnical behaviour', in AB Fourie & D Reid (eds), Paste 2024: Proceedings of the 26th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 151-158, https://doi.org/10.36487/ACG_repo/2455_11
(https://papers.acg.uwa.edu.au/p/2455_11_Reid/)
Abstract: The addition of polymers at or near to the point of deposition, perhaps most commonly referred to as inline flocculation and herein referred to as polymer treatment (PT), is an increasingly popular technique to improve the dewatering rates and consolidation behaviour of clay-rich tailings. Previous research has demonstrated that this process can significantly alter the geotechnical behaviour of some soils, including their consolidation characteristics and the critical state line. It has also been shown that shearing of slurries after the inline flocculation process can reduce some of the changes induced by the polymers. However, insufficient research has been conducted on the effects of long-term degradation of the polymers on geotechnical behaviour – something of particular importance if the strength of tailings in question are relied upon for stability. 
To investigate the effect of long-term polymer degradation, PT specimens were prepared for triaxial compression testing on a well-characterised clayey slurry. Attempts were then made to degrade the polymers through the flushing of hydrogen peroxide solution for specimens within the triaxial apparatus, followed by shearing to examine the response of the specimen. Results obtained have not been able to demonstrate appreciable changes to the mechanical behaviour of the PT specimens as a result of hydrogen peroxide flushing. However, the amount of flushing carried out was seen in a separate test to be insufficient to completely degrade the polymers.

Keywords: polymer treatment, polymer degradation, element testing, critical state line