Magnetic separation of diamagnetic particles

A new aspect of magnetic separation, the capture of diamagnetic particles in high gradient magnetic filters, is reported in detail for the first time. It is not generally realized that, in such systems, diamagnetic as well as paramagnetic particles may be captured and that the former undertake capture trajectories causing them to be held at the surfaces of fibres in angular sectors repulsive to paramagnetic particles. The angular width of these capture sectors is strongly dependent on the magnetic parameter (K = Ms/2μoHo). Capture curves have been computed for diamagnetic particles in all possible fibre/fluid flow orientations in filters.