Multiphase Electrodispersion Precipitation of Zirconia Powders

Abstract

ABSTRACTThe 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.