Preparation of ZrSiO<sub>4</sub> Powder Using Sol-Gel Process (Part 4)

Abstract

ZrSiO4 fine powders were prepared from zirconium oxychloride (ZrOCl2) and colloidal silica (SiO2). Effects of the concentration of ZrOCl2, calcination temperature, heating rate and size of secondary particles after hydrolysis on the preparation of ZrSiO4 fine powders have been studied. The ZrSiO4 precursors having Zr-O-Si bond were found in all the solutions after hydrolysis, and the formation rate of ZrSiO4 was influenced significantly by the concentration of ZrOCl2. Also the rate in the case of other concentrations than 0.4M was affected remarkably by heating rate, and there was a marked tendency for crystallization of ZrO2 and SiO2 to proceed preferentially and creation of ZrSiO4 nucleus to be obstructed when the heating rate was slow. It is shown that ZrSiO4 fine powders of the single phase were prepared at a relatively low temperature such as 1300°C by forming the ZrSiO4 precursors having Zr-O-Si bond and by controlling the secondary particle size after hydrolysis.