Traction force on paramagnetic particles in magnetic separators

The magnetic force, which attracts paramagnetic particles towards a magnetized ferromagnetic wire, is calculated for the geometry which is most likely to be used for magnetic separation. It is demonstrated that the magnetic field problem has an analytic solution, from which the maximum force is obtained analytically as a very simple expression. The choice of optimum wire diameter becomes less critical than in the estimation of Oberteuffer, since the maximum is flatter, but the position of this maximum is not changed significantly, and is the same for all practical purposes.