The applied pressure and suspension height during consolidation of a 15 vol% Al2O3 suspension (0.15 μm α-Al2O3 particles, isoelectric point pH 7.8) at pH 3 - 10 in a closed cylinder were continuously recorded using a pressure filtration apparatus. The apparent viscosity decreased with decreasing suspension pH. The final packing density of the dispersed acidic suspensions at pH 3.2 and 5.6 reached 62 – 63% at 19 MPa of applied pressure. The viscous basic suspensions at pH 7.8 and 9.6 were consolidated to 52 – 54 % density. Because of the release of the stored elastic strain energy, the height of the consolidated Al2O3 compact increased after releasing the pressure. The energy required to consolidate 1 cm3 of Al2O3 particles was in the range from 3.0 to 15.9 J, and became larger for the dispersed acidic suspensions. The energy applied between two colloidal particles during consolidation (W) was compared to the interaction energy (Ei) between two particles in a suspension.