A magnetic separator comprises a magnet (2) positioned at an angle (3) to the vertical and means (4) for feeding a mixture of magnetic and non-magnetic particulate material at or closely or adjacent the magnet in the region of high magnetic field. The non-magnetic particles fall under the action of gravity only whereas the magnetic particles are diverted towards the magnet until the gravitational force exceeds that exerted by the magnet. The arrangement provides a clean separation between the magnetic and non-magnetic particles and may be employed to separate the particules according to degree of magnetic susceptibility. A magnet (2) for a magnetic separator is also described comprising a linear superconducting magnet having a coil (36) with two generally straight portions (38) joined by curved ends (40). The coil is supported by a clamp (42) in a cryostat vessel (35) with the longest axis arranged horizontally and so as to provide a magnetic separation zone on one side of the coil. The magnet is powerful, robust and has a long range.