Separation of Fine Weakly Magnetic Particles by A High Gradient Magnetic Separation System

High Gradient Magnetic Separation (HGMS) for the fine treatment of industrial sludges was tried with several simulated ones. These sludges were made up of chemical reagents ofα-Fe2O3, Cr (OH) 3and SiO2, which were weakly magnetic materials and of smaller particle size than some 20μm. These samples were prepared in slurry and tested separately and by mixture with a cyclic Sala-HGMS 10-15-20 separator. In this report the change of magnetic capture through one cycle of separation was defined as magnetic capture process. Some experimental data were obtained in terms of the magnetic capture process. This process includes initial magnetic capture, build-up and breakthrough phenomena. Separation tests of a paramagnetic or weakly magnetic α-Fe2O3from a diamagnetic SiO2were successful with the separation efficiency of more than 90%. Some theoretical approaches of the experimental data were conducted by using the force balance model.