The ball matrix magnetic separator

The ability of a single ferromagnetic ball, magnetized by a uniform magnetic field and surrounded by equisized nonmagnetic balls, to capture magnetizable particles, carried by a fluid through the ball structure, is examined theoretically. It is found that the ability of the ball to capture these particles increases rapidly with an applied field, until the magnetization of the ball is saturated, and then the ability decreases with increasing applied field. A ball matrix magnetic separator consists of a collection of randomly packed equisized ferromagnetic spheres magnetized by an externally applied magnetic field. It has been found that the ability to collect magnetizable particles by such a system improves with increasing applied field until the ferromagnetic balls are magnetically saturated after which the ability to retain capture particles is almost independent of the applied field. This is in contrast to the behavior of a single ferromagnetic ball in free fluid flow whose ability to capture magnetizable particles continues to increase with applied magnetic field after the magnetization of the ball is saturated, it is suggested that the behavior of the ball matrix magnetic separator is largely determined by the geometry of the fluid flow through the matrix rather than by the magnetic properties of the matrix.