Treatment of Coolant of Hot Rolling Process by High Gradient Magnetic Separation

It is needed several large reservoirs and long operating time in order to remove suspended solid (SS) like steel fines and iron oxide at steel making factory. If removing rate of SS in coolant of hot rolling process can be increased, the productivity of working process can be increased and the area of reservoir can be reduced. We investigated the formation ability of magnetic flock which mixed with inorganic materials and polymer coagulants. Iron hydroxide and electrolytic dissociation were used for pretreatment. We assembled reciprocal superconducting HGMS system that had a purpose to remove SS of coolant at steel factory. The wire of filter was used stainless steel 420. Maximum coagulation formation rate of SS was 98%. Removing ratio of Fe₃O₄ fine particles in artificial wastewater showed over than 99% after four times of repetition of magnetic separation.