Open gradient magnetic separation in vacuum

The effects of particle size and ambient air pressure upon the performance of open gradient magnetic separation (OGMS) is studied. Good agreement between the theoretically predicted and experimentally established particle trajectories is found. The stability of a particle curtain, which deteriorates with decreasing particle size, is completely restored by reducing the air pressure to less than 14 torr. The restoration of the curtain stability is accompanied by considerable improvements in the grade and recovery values. This opens the way for dry, size-independent OGMS of micron-sized particles. >