Low temperature synthesis of high purity leucite

High purity leucite powders have been synthesized at 850 °C by sol–gel method. The effect of CaF2 as a modifier on the synthetic temperature and purity of leucite was investigated. DTA and XRD results indicated that the presence of 1.5 wt.% CaF2 could lower the synthesis temperature from 1100 °C to 850 °C and effectively eliminate crystallization of the common intergrowth kalsilite. After doping with 1.5 wt.% CaF2, the leucite synthesized at 850 °C had a crystal size of 0.8 μm, and its calculated coefficients of thermal expansion (20 °C to 400 °C) reached 29.50 × 10− 6/°C, which is very close to the theoretical value of pure leucite.