Abstract: Effects of ball milling parameters and additive amount of dispersant on the deagglomeration and the mechanical properties of vitrified bond aggregate were studied. Particle-size analyzer, scanning electron microscopy and universal materials testing machine were employed to characterize the particle size, the microstructure and the flexural strength of the vitrified bond powder before and after deagglomeration. The results indicate that the D₅₀ particle size of the vitrified bond powder is refined to 0.186 μm by employing smaller size (5 mm) of the grinding media, 2.5%(mass fraction) dispersant addition and 2 hours milling time. Meanwhile, the dispersion of the particle is good and there is no agglomeration after ball milling. The flexural strength of vitrified bond is 26.2 MPa after sintered at 700 ℃, which is about 45% higher than that of specimens made from raw powder.