One-Step Process for Particle Separation by Magnetic Seeding

Abstract

Particle separation by a one-step or “batch” magnetic seeding operation is investigated using a population balance modeling approach. This modeling technique accounts for the concurrent orthokinetic coagulation between magnetic seed particles, the orthokinetic coagulation between magnetic seed particles and target particles, and the removal of seed−target agglomerates from the batch reactor by a combination of gravitational and magnetic sedimentation. An exact solution is found if the seed particles are stable or if the seed particles are unstable and their removal rate is independent of cluster size. A more general “scaling theory” is also presented for the case where seed particles are removed under the influence of both gravitational and magnetic fields. The separation efficiency achieved by a particular time depends on a single dimensionless number, Ω, which represents the characteristic time scale for the heterocoagulation between seed and target particles divided by the residence time of single see...