Studies of the Surface Properties of a Particle-Water-Oil System and Their Relationship to the Agglomerate Formation in a Liquid

Abstract

Agglomeration experiments were carried out using BaSO₄ as model particles, sodium oleate (NaOl) as the surface active reagent and kerosene as the bridging liquid. The percentage of surface coverage of oleate on BaSO₄ required to achieve 90% recovery with flotation and agglomeration was about 13% and about 95%, respectively. From the results of agglomeration, phase inversion and flotation experiments, it is concluded that the particle-particle cohesive force due to negative capillary force is a necessary condition for agglomerate formation. This is a reason why a high surface coverage of oleate on BaSO₄ is required for agglomeration.
Simulations of agglomerate growth were conducted using the population balance equations derived by the authors. The equations consist of a collision frequency function and a coalescence probability, formulated on the basis of Kolmogoroff's theory under isotropic turbulent flow conditions and the physical properties of agglomerates. Both the experimental and simulated results showed that agglomerate growth was restricted by a characteristic agglomerate diameter (C_D) which increased with increasing γcos θ and φ_B and with decreasing N_I and ε as expressed in Eq. (11).