Removal of Magnetic Fine Particles From Carbon Black Powder by High Gradient Magnetic Separation Under Dry Condition

Removal of magnetic fine particles from carbon-black powder by utilizing the high gradient magnetic separation with a newly developed magnetic wire filter under dry condition was studied. The developed magnetic filtering system has magnetic thin wires arranged in one direction with a regular interval and the rotating layered structure perpendicular to the magnetic field direction. This makes it possible to capture the magnetic fine particles without clogging the filter under dry condition. The capture rate in the magnetic filter was investigated in detail by both magnetic separation experiments and three-dimensional FEM particle trajectory simulations. With reducing both the magnetic wire size and the wire spacing, and with increasing the number of layers, the capture rate increased significantly. By optimizing the filter design, we succeeded in removing 100% of iron particles with a size of 48 microns in carbon black powder under low magnetic fields without clogging the filter. Consequently, it became clear that the newly developed filter is very effective in removing magnetic particles in the powder under dry condition.