Abstract:

The CaZrO₃ powder precursors were prepared from raw material of Ca(OH)₂ and ZrOCl₂, KOH as the mineralizer, under the hydrothermal reaction conditions of 15-250℃ and 6-12h. The CaZrO₃ powder was obtained by calcing the precursors at 900-1000℃. The article discussed the effects of the ratio of Ca to Zr in raw material, crystal temperature, crystal time and pH of solution on the structure and state of the product from hydrothermal synthesis, as well as the effect of calcing temperature on the crystal microstructure of CaZrO₃. The results of XRD and SEM show that the crystal of CaZrO₃ can be obtained under the conditions of n(Ca):n(Zr)=2:1, at 200℃, for 6h and calcing temperature of 900℃. With the rising of synthesis temperature, the lasting of crystal time and the rising of calcing temperature, the crystal grain size increases, and has less aggregation. When the particle size is in the range of 0.5-3.0μm,the CaZrO₃
powder has a good sintering activity and may be used as a refractory.

Key words: calcium zirconate, hydrothermal synthesis, calcine, microstructure