This study aimed to understand the dewatering behaviour of three types of clay minerals (i.e. kaolinite, bentonite, and illite) in saline water, and in particular the effect of factors including clay mineralogy, clay suspended solid concentration, water salinity, and polymer flocculant dosage on dewatering behaviour. It was demonstrated that the addition of polymer flocculants helped all three clay types to settle due to the polymer bridging effect In saline water, this bridging effect worked best above a certain threshold level for illite but tailed off for the other two clay types. As well, high-salinity water was observed to assist bentonite and illite to settle faster but to hinder the settling rate of kaolinite. In addition to inter-particle forces, the clay aggregate structures formed through the addition of the flocculants were identified to play an important role in determining the dewatering behaviour of clay minerals in saline water. Cryo-scanning electron microscopy (SEM) identified that, depending on the clay type, the floc structures in saline water were either dense (water-excluding) or loose (water-trapping). Dense flocs were observed to settle more quickly than loose flocs. This study has practical applications in providing guidance for the processing of complex tailings containing clay minerals in saline water. (C) 2017 Elsevier B.V. All rights reserved.