Bouchard, ML, Leclerc, A, Simard, G & Peloquin, G 2010, 'Diagnosis of mud displacement in gravity settlers from analysis of their residence time distribution', in R Jewell & AB Fourie (eds), Paste 2010: Proceedings of the Thirteenth International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 61-72, https://doi.org/10.36487/ACG_rep/1063_6_Bouchard
(https://papers.acg.uwa.edu.au/p/1063_6_Bouchard/)
Abstract: Knowledge of the residence time distributions (RTD) of solid particles through gravity settlers of the Bayer 
process is essential to verify that they are operated effectively. Moreover, the RTD may be used to diagnose 
some common problems occurring in settlers, like channelling and dead zone or to evaluate the effectiveness 
of certain operational parameters, such as rake configuration. Because of the aggressive chemical 
environment of the Bayer process it is difficult to realise RTD measurements. To monitor the mud 
displacement, a ferromagnetic iron tracer was used with a new on line electromagnetic inductance 
measurement method that has been described previously. Sedimentation tests performed in a laboratory 
settler confirmed the effectiveness of this approach. In addition, a new method of RTD curves’ decomposition 
has been used in order to facilitate the analysis of the data. This paper describes briefly the experimental 
apparatus and presents an analysis of the RTD data obtained with our laboratory settler based on this novel 
curve decomposition technique.