Purification of the Coolant for Hot Roller by Superconducting Magnetic Separation

It is important to recycle industrial wastewater in the aspect of energy saving and minimizing the environment damage. Steel manufacture factories make an effort to purify and recycle wastewater from the manufacturing processes. A steel manufactory in Korea, POSCO (POhang iron and Steel COmpany) has also concerned about the treatment of wastewater for long time. The coolant of hot roller at steel making factory includes suspended solid (SS) like steel fines, iron oxide and emulsified oil. A laboratory-scale conduction cooled high temperature superconducting (HTS) magnet was used for high gradient magnetic separation (HGMS) systems. It consists of eight double-pancake sub-coils, two HTS current leads, a GM cryo-cooler and a cryostat without a radiation shield vessel. Sub coils were wound with 1 G HTS tapes of Sumitomo Electric Industries by wet-winding method. A Cryo-cooled high temperature superconducting magnet system with 70 mm room temperature bore and 250 mm of height was prepared. This magnet was used for batch type HGMS system. Superconducting HGMS system that had a purpose to purify the wastewater was assembled. Various magnetic seeding reactions were investigated to increase the reactivity of coagulation.