Particle sedimentation models for a commercial lithium extraction process from brine

•The observation of particle sedimentation behaviors with and without agitation.•The development of a one-dimensional unsteady-state model describing the experimental phenomena.•A proposed critical boundary to avert/decelerate particle sedimentation. This work assesses and examines particle sedimentation behaviors for magnesium removal process in a commercial lithium recovery plan with the aid of a lab-scale stirred tank reactor in the presence and absence of rotational stirring. The effects of stirrer agitation rate on the sediment height and induction period were investigated in the range of 280–390 RPM. A one-dimensional unsteady-state model was utilized, capable of describing the main phenomena observed in experimental particle sedimentation tests. The model showed fair agreement with experimental results obtained for the batch-wise sedimentation at different agitation rates. Moreover, the model was further used to assess the particle sedimentation behaviors in batch-wise and continuous stirred tank reactors. A critical boundary, based on a critical Peclet number and initial solid volume fraction, was proposed to avert/decelerate particle sedimentation in both reactor configurations, which could provide operation guidelines for batch and continuous reactors.