ABSTRACT
Magnetic force is proportional to the product of the external magnetic field and the field gradient and has the direction of the gradient. Several competing forces act on the particles placed in a magnetic separator. These are the force of gravity, the inertial force, the hydrodynamic drag, and surface and interparticle forces. Magnetic particles will be separated from “nonmagnetic”. Ferromagnetic material is an ensemble of small magnetic domains within which the magnetic moment is unidirectional. The development of permanent magnetic materials and the improvement on their magnetic properties have been particularly studied. The high permeability, low coercive force, and high saturation magnetization of soft magnetic materials are used in certain applications. The industry employed ferrites at low power levels; however, nowadays higher power levels of ferrites have been developed. Magnetic fluid is one example of an apparent superparamagnetic behavior described by the same Langevin’s law, where the Brownian or Neel mechanisms lead.
