Thickened tailings loop test to corroborate the hydraulic Hanks model and Buckingham equation

Authors: Vilela, L; Pinto, D; Ramos, G Download Paper Open access courtesy of:

DOI https://doi.org/10.36487/ACG_repo/2115_12

Cite As:
Vilela, L, Pinto, D & Ramos, G 2021, 'Thickened tailings loop test to corroborate the hydraulic Hanks model and Buckingham equation', in AB Fourie & D Reid (eds), Paste 2021: Proceedings of the 24th International Conference on Paste, Thickened and Filtered Tailings, Australian Centre for Geomechanics, Perth, pp. 131-142, https://doi.org/10.36487/ACG_repo/2115_12



Abstract:
The disposal of diluted tailings in dams, due to their muddy state, becomes inherently difficult to contain and this poses a high risk to society, as observed in the last two accidents that occurred in Brazil in 2015 and 2019. Therefore, the disposal of coarser tailings becomes more relevant because besides contributing to the reduction of water consumption and environmental impact, it will also require a smaller disposal area. However, to transport a thicker slurry, the viscosity and the yield stress of the tailings will increase. Therefore, for long distance conveying systems, high friction losses are generated in the pipeline. In view of the high operating pressures and the low experience with these pumping systems, it is important to consolidate the hydraulic model used in the design. The loop test setup in this case was used to support the selected hydraulic model. Based on data from a loop test set up at a Brazilian mining company located in the Iron Quadrangle (Quadrilátero Ferrífero), the study proposes to validate the Hanks & Dadia (1971) model using yield stress correction according to the Buckingham equation presented by Abulnaga (2002). In the loop test, the fine iron ore tailings were pumped using positive displacement pumps. The viscosity of the tailings varied between 0.013 and 0.017 Pa.s and the yield stress between 31 and 42 Pa. Very close results were observed between the actual data from the loop test and the head loss calculation by the Hanks & Dadia (1971) model using the yield stress correction, according to the Buckingham equation.

Keywords: Hanks model, loop test, thicker slurry, tailings, rheology

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