On Preparation of CaZrO_3 Powder by Hydrothermal Synthesis Method

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 150-250℃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.