Investigation on the Sedimentation Behavior of the α-Al2O3 Aqueous Suspension by the Combination of Two Dispersants

The effect of three different types dispersants on the stability behavior of alumina aqueous suspension were investigated by through sedimentation experiment , Zeta potential ,and residual porosity of sintered sample. The results showed that the optimal content and optimal sedimentation pH value of the three different types dispersants were 1.0% and aging at pH9 for PAA-NH4, 0.8% and nearly independent of pH value for Arabic gum , 0.4, 0.2 and aging at pH9 for PAA-NH4 and Arabic gum，respectively. The dispersion effect of the three different type dispersants was PAA-NH4and Arabic gum> PAA-NH4 > Arabic gum. Studies have shown that the combination of PAA-NH4 and Arabic gum has a better effect than one of them on the stability of suspension. Compared with single dispersant, the sedimentation volumes of the two dispersants dispersing suspension is reduced 3%, the dosage of dispersants is reduced 26.7%.