Fitton, TG & Seddon, KD 2012, 'Relating Atterberg limits to rheology', in R Jewell, AB Fourie & A Paterson (eds), Paste 2012: Proceedings of the 15th International Seminar on Paste and Thickened Tailings
, Australian Centre for Geomechanics, Perth, pp. 273-284, https://doi.org/10.36487/ACG_rep/1263_23_Fitton
The combination of rheology and soil mechanics is a relatively rare occurrence. Both fields are generally applied in quite separate circumstances, not usually at the same time. However, the transport and storage of thickened tailings slurries has created a situation in which both of these fields do come together. Whilst a thickened tailings slurry is flowing, it can be considered as a fluid. Rheometric equipment can be used to measure its flow properties, and rheological models and theories can be successfully applied to describe its behaviour. Once the tailings slurry is discharged into a storage facility, it typically flows across a ‘beach’ of previously deposited tailings, and eventually comes to rest. From this point onwards, the tailings particles are often considered as a soil, and the models and theories of soil mechanics then apply in describing the behaviour of the material.
Tailings engineers often measure both the rheology and plasticity (by the use of the Atterberg limits test) of tailings materials in order to design for the transport and containment of the tailings, but sometimes samples are not available for testing, and documented lab test data for only one of these two aspects may exist. This paper presents new empirical relationships for the estimation of one from the other, based on a data set featuring 26 different tailings samples.
Much of the observed variability in rheology can be accounted for by the plasticity of the material.
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