Magnetic separator operating in a wet environment

A high-intensity magnetic separator operating in a wet environment for separating magnetic particles from a fluid material containing said particles, the magnetic separator comprising at least one separating unit which comprises

• (a) a vertically extending housing having side walls defining a separating chamber,
• (b) means for alternately circulating the fluid material and a washing liquid vertically downwardly through the separating chamber,
• (c) permanent magnet means arranged adjacent the side walls of the housing for generating therebetween a magnetic field extending perpendicularly to the direction of circulation of the fluid material in the separating chamber, and
• (d) means for displacing the permanent magnet means relative to each other and to the separating chamber between a first position in which the permanent magnet means are in contact with the side walls of the housing so that the magnetic field is intense enough to retain the magnetic particles in the separating chamber while the fluid material is circulated therethrough in a separating phase, and a second position wherein the permanent magnet means are so remote from the side walls of the housing that the magnetic field is sufficiently attenuated to allow the magnetic particles retained in the separating chamber to be released while the washing liquid is circulated therethrough to evacuate the magnetic particles from the chamber in a washing phase.