Magnetic classification.

Differential magnetic classification is defined as the ability to classify a range of magnetic particles into classes of magnetic susceptibility, as opposed to selective magnetic separation of a single magnetic particle type from all others. The attempts to achieve some sort of magnetic classification are reviewed and the first optimised magnetic separator and classifier is briefly described. A number of factors are critical: particle radius must have no influence or negligible influence on outcome; particle trajectories must be as perpendicular as possible to the direction of field gradient increase until the particles are classified; the magnetic force must be opposed by a fully controlled force acting in the opposite direction, and another force acting in some other direction must also exist; and the magnetic force must have a long range or the trajectory of particles under the field gradient's influence must be long enough.
Differential magnetic classification is defined as the ability to classify a range of magnetic particles into classes of magnetic susceptibility, as opposed to selective magnetic separation of a single magnetic particle type from all others. The attempts to achieve some sort of magnetic classification are reviewed and the first optimised magnetic separator and classifier is briefly described. A number of factors are critical: particle radius must have no influence or negligible influence on outcome; particle trajectories must be as perpendicular as possible to the direction of field gradient increase until the particles are classified; the magnetic force must be opposed by a fully controlled force acting in the opposite direction, and another force acting in some other direction must also exist; and the magnetic force must have a long range or the trajectory of particles under the field gradient's influence must be long enough.