Preparation of zirconia granules with a low molecular weight dispersant

Abstract

In the present work, different conditions, such as PVA content as a high molecular weight polymer, Dolapix CE64 level with a lower molecular weight and pH adjusted by HCl, were investigated for the preparation of the yttria-stabilized zirconia (YSZ) granules from nanosized YSZ particles. It was found that the suspension prepared at pH = 4 and with 0.1 wt.% Dolapix CE64 has a reasonable value of viscosity for spray drying. The morphology of granules and their cross-sections were characterized through microstructural observation. The flowability of the prepared granules and the Hausner ratio were also evaluated. The results indicated that the addition of only 0.1 wt.% of PVA binder and the use of Dolapix can produce the YSZ granules with good flowability. Replacement of PAA by Dolapix has the benefits of achieving uniform granules with a dense shell layer, decreasing the amount of binder and accelerating the feeding rate of suspensions. The mechanism of the solid and hollow granule formation by a low molecular weight dispersant was suggested.

Keywords

• ysz granules
• dolapix
• pva binder
• flowability