Permanent magnet ring separator

A magnetic particle separator comprising:

• a plurality of permanent magnet segments forming a cylinder having a bore, each of said plurality of permanent magnet segments having a magnetic remanence and magnetic direction, the plurality of permanent magnet segments assembled such that the remanence of said plurality of permanent magnet segments increases from one surface of the cylinder to an opposing surface of the cylinder and the magnetic direction of each of said plurality of permanent magnets is rotated substantially uniformly from the one surface of the cylinder to the opposing surface of the cylinder wherein the magnetic direction of each segment varies linearly with a progression along an azimuthal coordinate angle as .gamma.=2.theta., where .theta. represents the desired angle of magnetic direction and .theta. represents an angle between a central axis and a predetermined orientation angle so that a transverse magnetic field gradient having a higher magnetic field region and a lower magnetic field region is formed;
• a pipe placed within the bore of the cylinder formed by said plurality of permanent magnet segments, said pipe having an input and an output end;
• a divider placed transversely in said pipe near the output end, said divider separating the pipe longitudinally along a portion of its length into a high density opening near the higher magnetic field region and a low density opening near the lower magnetic field region;
• a collector coupled to the higher density opening;
• and
• a pump coupled to the input end of said pipe, said pump forcing material longitudinally down the pipe.