Abstract：The dispersant was added in the process of fine crushing of the permanent magnetic ferrite. The disperse state of the slurry of permanent magnetic ferrite was tested by Fisher sub-sieve sizer, viscosity meter, and electrophoresis. The slurry particle size and distribution were compared by the sedimentation method. The orientation of crystal c-plane of green ferrite was analyzed by XRD. The magnetic property of the permanent ferrite was tested by permanent magnetic standard gauge. The results show that the slurry flow, zeta potential values, orientation of crystal c-plane of the green ferrite are significantly improved after adding a dispersant, and the increase rate reaches greater than18%. The effect of pair combinations of the complex dispersants improving the crystal c-plane orientation of the green ferrite is better than that of a single dispersing agent. The dispersant agent D complexed by dispersant agent A, B and C actually improves the fluidity of the slurry, zeta potential values, and crystal c-plane orientation of the green ferrite. After sintering, the cracking problem of magnet and magnetic parameters of the permanent ferrite such as residual magnetic flux density, degree of orientation, and coercive force also have a more significant improvement. When the pellet surface of the ferrite is modified by the dispersing agent D with mass fraction between 0.5% and1.0%, it is desirable to adjust the p H value of the permanent magnetic ferrite slurry from 8 to 11 with ammonia.

Keywords: permanent magnetic ferrite; dispersant; slurry; magnetic property; viscosity