In-situ observation of particle deposition process during high gradient magnetic separation

Deposition process of magnetic particles on two filters during high gradient magnetic separation has been investigated through in-situ optical observation. The deposition process was observed from two perpendicular directions using CCD cameras. In case of relatively high concentration suspension, due to their particle-particle interactions, particles formed the chain or the bundle structures in the flow path before reaching the filters. Such chains and bundles tend to be deposited on the first filter and the spike like structure was formed at the upper stream side of the first filter. On the other hand, particles deposited uniformly on the second filter. These observation results show that it is required to take into account properly the effect of the deposited particles in the sense of the magnetic field distribution and also of the physical obstructions to understand separation performance precisely.