Magnetic drum separator

A magnetic drum separator, comprising:

• a drum rotatable about an axis relative to a frame, wherein the drum comprises an internal chamber and an opening at an end of the drum that provides access into the internal chamber;
• an inlet for supplying a liquid or granular substance into the internal chamber through the opening at the end of the drum;
• a magnet arranged outside of the drum for attracting magnetic material comprised in the liquid or granular substance towards an internal sidewall of the internal chamber;
• a collection device for recovering at least a proportion of the magnetic material attracted to the internal sidewall;
• an annular seal member attached to the end of the drum, wherein the annular seal member rotates with the drum in use;
• and
• a baffle that bears against the annular seal member and partially seals the opening at the end of the drum,
• wherein a plurality of cavities are formed in the annular seal member, the cavities being adapted to receive fluid leaking into a boundary between the annular seal member and the baffle.