The consolidation of concentrated suspensions. Part 1.—The theory of sedimentation

Colloidal Processing of Ceramics

“…92 and centrifugation. 3,[92][93][94] In centrifugation, this property can be assessed by measurement of either sediment height at multiple spinning speeds, volume fraction profile during centrifugation by destructive sectioning, or ␥-ray densitometry. A schematic illustration of the coordinate system for the centrifugation method is shown in Fig.…”

Highly Nonlinear Dynamics in a Slowly Sedimenting Colloidal Gel

“…Although they exhibit solid-like mechanical properties, colloidal gels are easily disrupted by small perturbations, such as gravitational forces. While a large body of macroscopic observations of gels under gravitational stress exists [5][6][7][8][9][10][11][12][13], very little is known on the microscopic processes at play during sedimentation, thus limiting our ability to understand and predict the behavior of sedimenting gels.Here, we use a novel light scattering method to gain access to the dynamics of a slowly settling colloidal system from the macroscopic deformation of the sample down to the relaxational behavior at the particle scale. We find that the very slow macroscopic deformation occurs via irreversible plastic events at the microscopic scale.…”

“…Our detailed set of measurements allows us to perform a rigorous quantitative test of the modeling of gels as a "poroelastic" medium pioneered by Buscall and White [5] and used in several studies [11][12][13]21]. The modeling simplifies in the absence of wall friction.…”

“…Accordingly, no significant fraction of the gravitational stress is redirected on the walls, making wall friction vanish, as suggested also by the observation that changing the cell section from 3 × 3 mm 2 to 5 × 5 mm 2 does not change the evolution of h, ϕ, v nor that of the microscopic dynamics discussed below. Neglecting inertial terms, by balancing the gravitational stress on a gel slice by the sum of the viscous stress, due to the flow of the suspending fluid through the network, and the restoring stress resulting from the gel response to a deformation, one gets [5,23]:…”

Modelling and simulation of batch pressure filter cycles

“…The software lays the foundation for design procedures which may incorporate more comprehensive models for cake formation [6][7][8][9][10] , which are based on more rigorous models of suspension flows and particle deposition, as they become sufficiently practicable. The software utilises industrially proven methodologies that are combined with computer code to produce modular routines capable of modelling cake formation, compression dewatering and washing.…”