The multiphase electrodispersion precipitation of zirconia powders has been
done in the electric dispersion reactor (EDR). This paper presents the first
results obtained where the bench-scale EDR unit was operated in the
continuous mode to synthesize 130 ± 2 g of ZrO2 powder in
approximately 12 h. An aqueous solution of zirconyl nitrate was dispersed
and precipitated in a 2-ethyl-l-hexanol continuous phase containing 0.012
M to 0.12 M ammonia. A
gravity settler was used to remove soft agglomerates of the ZrO2
particles from the organic solvent. Electric bed filtration was employed to
remove the fines from the solvent, which was then recycled.
The particle-size distribution was varied by changing the electric field
strength. At high field strengths (approximately 20 kV/cm), the particle
sizes ranged from approximately 0.1 to 5 μm. The dried powder had a
consistency of talcum powder. Microwave and conventional heating experiments
showed that the powders were sinterable. The BET surface area of the powders
ranged from approximately 20 to 90 m2/g.