A dewatering process comprises dispersing an anionic polymer flocculant in a slurry comprising water and oil sands fine tailings to form flocs comprising fines bridged by the anionic polymer flocculant. A cationic polymer flocculant is subsequently dispersed in the flocculated slurry to further flocculate the flocs and form floc aggregates. The floc aggregates comprise flocs bridged by the cationic polymer flocculant. The floc aggregates are then compressed to remove water and form a dewatered compact. A system is also provided for the dewatering processes using inline mixtures and a filter press.