Solid-liquid magnetic separation using bulk superconducting magnets

Our research is to magnetize the high-T_c bulk superconductors and to supply magnetic field environment realized by superconducting bulk magnets to various applications. In this paper, we aim to apply the superconducting bulk magnets to the high gradient magnetic separation (HGMS). Using a face-to-face type superconducting bulk magnet system in which a pair of bulk superconductors are oppositely arranged, Y123 bulk superconductors are magnetized by the "IMRA" method (pulsed field magnetization), and consequently, a magnetic field of 1.6 T is achieved between the magnetic poles. Next, HGMS using superconducting bulk magnets is demonstrated. A separation pipe into which filter matrices composed by ferromagnetic wires are stuffed is set between the magnetic poles and the slurry mixed with fine powder of α-hematite (Fe₂O₃) particles is flown. As the results of HGMS, over 90% of the Fe₂O₃ was separated. Moreover, separation filters have to be washed so that they are not clogged with captured particles. We confirmed that the filter was briefly washed by flowing water after moving the separation pipe from magnetic poles.