In the characterisation of solid-liquid separation of suspensions it has been common in the past to either focus on the free settling region of the suspension or on the behaviour of networked suspension either in the form of a sediment or a filter cake. Combination of results from these regimes is seldom completed and, if more complete knowledge of the characterisation from individual particles to a fully networked system is required, it is necessary consider the solid-liquid separation data over a wide range of solids concentration. The current paper investigates the settling behaviour (free settling region), gel point, phi(g) (transition point) and compressive yield stress, P-y(phi) (sediment bed region) in the characterisation of the kaolinite-sodium chloride systems from the un-networked state through to the fully networked state. It was found that settling behaviour of kaolinite changes with both ionic strength and pH of the suspension. In acidic pH range (pH 2) particles settle in flocculated form regardless of electrolyte concentration: however, in basic pH ranges, the particles settle both, dispersed form (in low electrolyte concentration) and flocculated form (in high electrolyte concentration). On the other hand, the gel point and sediment bed behaviour are found to be very sensitive to the type of the inter-particle interactions. Face-face (F-F) flocculation produces higher gel points and higher apparent maximum packing fractions while edge-face (E-F) flocculation produces higher compressive yield stresses at all volume fractions. These results show good correlations between the settling behaviour, gel point, and compressive yield stress for the different kaolinite particle interactions. (C) 2005 Elsevier B.V. All rights reserved.