Magnetic separation of kaolin clay with amorphous ferromagnetic fiber

Approximately 2-3% Fe2O3as limo nite is contained in kaolin clay (Al2O3.2SiO2. 2H2O) in Suzhou, China. In this paper three kinds of amorphous ferromagnetic fibers were chosen as media in high extraction magnetic filtration (HEMF) for kaolin clay: 1. Fe63Ni15Si7B15; 2. Fe75Cr5P13C7; 3. Fe73Cr7P13C7;. The amorphous ferromagnetic fiber should possess the properties of noncorrosion and produce a high magnetic field gradient in an external field. In this article, corrosion-polarization curves, HEMF efficiencies of three sorts of amorphous fiber and the effect of width of fibers on HEMF in various external fields are given. Evidently the efficiency of extraction magnetic filtration of narrow fibers is better than those of the wider one. The amorphous ferromagnetic fibers of Fe75Cr5P13C7(width about 0.2 mm) have the best separation effect. This medium can reduce the Fe²O3content from 2.01 wt% (crude ore slurry ) to 0.70 wt%.