Sellgren, A 2012, 'Advances in thickened tailings pumping using centrifugal pumps', 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. 285-295, https://doi.org/10.36487/ACG_rep/1263_24_Sellgren (https://papers.acg.uwa.edu.au/p/1263_24_Sellgren/) Abstract: Reduction in pumping head and efficiency and unstable head observations at flow rates below about 50% of the best efficiency point (BEP) are discussed based on experimental results for solids concentrations by volume of up to 49% with authentic tailings products for a 0.1 by 0.075 m pump with impellers (diameter 0.31 m) of different configurations. Yield stresses were up to 200 Pa as an average and evaluated from pipeline loop testing. It has been reported for highly concentrated slurries that cavitational behaviour with drops in head and efficiency may occur at lower flow rates than that of water in the BEP-region. The experimental data for the tailings above did not cover this region. However, test data were available for the same type and size of standard pump by Kabamba (2007) for a kaolin slurry with a yield stress of 185 Pa. Evaluations here showed incipient cavitation from about 75% of the BEP-flow rate. Deratings in head and efficiency and effects related to unstable head tendencies and suction performance can be expected to diminish for pumps larger than the unit focused on here.