Batch gravity consolidation–sedimentation experiments were performed using highly concentrated suspensions of titanium diox- ide particles in order to examine the effects of the solution pH, the initial height, and the initial concentration of the suspension on the consolidation–sedimentation behaviors. The critical porosity where consolidation–sedimentation was encountered from the beginning of sedimentation was evaluated from the determination of the internal porosity of flocs based upon Michaels and Bolger's method. The subsidence rate of the consolidated sediment in consolidation–sedimentation attained its minimum value