Polyaluminum chloride (PACl) was introduced as a flocculant to reduce the entrainment of sericite gangue in fine flaky graphite flotation. The dispersion and aggregation behaviours of sericite and fine flaky graphite in the absence and presence of PACl were studied by settling experiments and verified by optical microscope images. Results of batch flotation tests for artificial mixtures indicated that the addition of PACl decreased the recovery of sericite gangue and the water recovery. Zeta potential measurements, FTIR and XPS analyses revealed that PACl selectively aggregated sericite particles in terms of charge neutralization and precipitate enmeshment.