Modelling of Binder-Induced Agglomeration

Abstract

From the analysis of pendular liquid bridge forces between spherical particles, a model has been developed to predict bridge rupture energies. Whilst this model has been shown to predict the correct trends in certain stages of agglomeration, it is limited by the assumptions of zero contact angle, toroidal bridge geometry, spherical particles and quasi-static rupture. The work described here is aimed at extending the model to more generally applicable conditions using direct measurement of bridge rupture energies between particles down to 3 m in diameter under different physiochemical conditions. Initial results show that the spreading coefficient of the binder to the particle has a marked effect on the dynamic behaviour of the bridge itself and its subsequent geometry at equilibrium, i.e. for non-zero contact angles theoretical equations tend to over-predict the force of adhesion, whilst for zero contact angles the force of adhesion agrees with that predicted using the Laplace equations for constant curvature. On the other hand, the corrected expression for maximum separation distance shows good agreement with experimental results.

Experimental study of oblique impact between dry spheres and liquid layers

“…To the best of our knowledge, t rup is proportional to the rupture energy (W rup ), and W rup increases with the liquid bridge volume, V (W rup ∼ V ) [30]. Concerning the present study, V increases with the layer thickness, causing an increase of W rup and a growth of t rup .…”

Measurement of Vacuum Residue and Asphaltene Fluid Properties at Process Conditions

“…FT = Fs + Fv (6) The total force, FT is measured experimentally, while the contributions from surface forces and viscous forces are Fs and Fv, respectively. When the liquid bridge elongates, so that D > b, then the force becomes: (7) similar to the relationships given by Fairbrother and Simons 25) and Pitois et al 23),24) . When the bridge is very short, with D < b, then Eq.…”

A generalized analytical energy balance model for evaluating agglomeration from a binary collision of wet particles

“…Extensive studies on the outcome of a collision between wet solid surfaces, principally a binary collision of identical wet particles or a wet collision between a particle and a plate, (agglomeration or rebound) are reported in literature through either experiment [ [9] , [10] , [11] , [12] , [13] ] or modeling. One can classify the latter category in three groups on the basis of adopted assumptions: (i) some assumed that collision behavior is dominated by capillary effects [ 6 , [14] , [15] , [16] , [17] ]; (ii) some postulated that viscous effects are dominant [ [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] ]; and (iii) others considered that both the capillary and viscous effects simultaneously govern the collision behavior [ 2 , [27] , [28] , [29] , [30] , [31] , [32] ]. The proposed models in most of these studies, except the one proposed by Balakin et al [ 29 ], are for a binary collision of identical wet particles or a wet collision between a particle and a plate.…”