Uncertainty ranges in estimating e0 and low-density consolidation characteristics for polymer treatment assessments

Authors: Boxill, L; Loan, M; Utting, L; Reid, D Download Paper

DOI https://doi.org/10.36487/ACG_rep/1752_28_Boxill

Cite As:
Boxill, L, Loan, M, Utting, L & Reid, D 2017, 'Uncertainty ranges in estimating e0 and low-density consolidation characteristics for polymer treatment assessments', in A Wu & R Jewell (eds), Paste 2017: Proceedings of the 20th International Seminar on Paste and Thickened Tailings, University of Science and Technology Beijing, Beijing, pp. 250-259, https://doi.org/10.36487/ACG_rep/1752_28_Boxill



Abstract:
Estimation of e0 is an important parameter when gaining information on the behaviour of tailings after polymer treatment, as it is a critical input when trying to predict field scale consolidation behaviour with the use of modelling techniques. Many laboratory experiments were undertaken to determine the uncertainty ranges in estimated values of e0, varying both the starting height of the tailings, starting solids concentration, with and without polymer treatment in beakers, graduated cylinders and custom built 10 L columns with evenly spaced sample ports. 95% confidence intervals range from 0.047~0.14 for e0 values in the range of 3.5~4.5 highlighting the robustness of the experimental methods and the viability of using experimentally determined e0 as an input for consolidation modelling. Sample ageing and solids concentration were found to have an impact on compressibility and permeability behaviour of the suspensions, however it is likely that the variability relates to an increased polymer demand rather than variation of the consolidation behaviour of the material itself. Observations made using varying starting height of the tailings suggest that this factor has no impact on void ratio, however increasing the internal diameter of the vessels used to measure the void ratio at varying effective stress suggests that wall effects may be a factor for slurries with high solids densities.

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