Vibrating high gradient magnetic separation for purification of iron impurities under dry condition

An innovative dry vibrating high gradient magnetic separation (HGMS) method was developed for the purification of non-metallic ores, and the effect of key variables, i.e., magnetic induction, rotation speed of ring, vibrating amplitude and frequency of ring on the separation performance of a full-scale dry vibrating HGMS separator in purifying kaolin was investigated. The results of investigation indicate that the variables have significant influence on the performance of the separator; an increase in the magnetic induction and rotation speed of ring reduce the mass weight but increase the iron removal rate of nonmagnetic product, and the increase in the vibrating amplitude and frequency of ring cause a rise in the mass weight but a drop in the removal rate. While all the variables were kept optimum, a nonmagnetic product assaying 0.50% Fe2O3 with 84.56% mass weight and 42.08% iron removal rate was obtained from the material assaying 0.73% Fe2O3. It was concluded that this dry vibrating HGMS is effective in eliminating powder coagulations during its separation process and provides a prospective method for the purification of non-metallic ores.

► An innovative dry vibrating HGMS is developed, with vibration in magnetic matrix.
► The vibration of magnetic matrix is effective in eliminating powder coagulations.
► It is crucial that the intensity of vibration is appropriate to obtain high selectivity.
► The dry vibrating HGMS method is effective in purifying this kaolin material.