Abstract： Equivalent spherical toners were prepared by a self-developed controlled air jet mill. The particle shape of toners was controlled by changing grinding strength, rotation rate of the first stage classifier, and secondary flow of the first stage classifier. The particle size distribution of toners was controlled by changing rotation rate of the second stage classifier and secondary flow of the second stage classifier. The results show that when the grinding strength of fluidized bed is 0.6 MPa, the secondary flow at the bottom of fluidized bed is 86 m³/h, the frequency of the first stage motor frequency converter is 17 Hz, the frequency of the second stage motor frequency converter is 36 Hz, and the secondary flow of the second stage classifier is 287 m³/h, relatively centralized particle size distribution, even particle shape and higher sophericity are obtained. The production yield is 72.5 kg/h and the qualified rate is 79.2%.

Keywords: toner; controlled air grinding; air classification; equivalent spherical