The first stage of clarification is to separate the solids (bauxite residue) from the pregnant liquor (sodium aluminate remains in solution) via sedimentation. Chemical additives (flocculants) are added to assist the sedimentation process. The bauxite residue sinks to the bottom of the settling tanks, then is transferred to the washing tanks, where it undergoes a series of washing stages to recover the caustic soda (which is reused in the digestion process).

Further separation of the pregnant liquor from the bauxite residue is performed utilising a series of security filters. The purpose of the security filters is to ensure that the final product is not contaminated with impurities present in the residue.

Depending on the requirements of the residue storage facility, further thickening, filtration and/or neutralisation stages are employed prior to it being pumped to the bauxite residue disposal area.