OGMS of cryogenically enhanced magnetics

The magnetic susceptibility of paramagnetic particles is enhanced by cryogenic treatment. The subsequent increased response to a magnetic force density is exploited to enhance particle deflection in open gradient magnetic separation (OGMS). Both grade and recovery values are considerably increased by the cryogenic treatment of the feed material. The cryogenic method is most useful if the response of the magnetic susceptibility of the involved particle phases is unequal, with the more magnetic phase showing a greater change. A number of commercially important mixed minerals are separated by this method, thus establishing the feasibility of cryoseparation. In those cases treated, in which the separation shows a very poor recovery of the more magnetic phase at room temperature, the cryogenic enhancement improves the outcome of the separation considerably, such that the process becomes perfectly viable at 80 K