SYNTHESIS OF LEUCITE

Abstract

Leucite, a potassium alumino-silicate (KAlSi2O6), is a very promising material for dental applications. It was initially introduced into dental porcelain compositions to adjust the thermal expansion coefficient of the ceramic to be similar to that of metal [1,2,11,12]. The mineral leucite was synthesized by melting the mixture of KNO3, Al(OH)3 and Cam Ranh sand in the fire of acetylene burner, which can increase the temperature to around 2000 – 2200oC. The obtained material has the following properties: bulk density ρ = 2,48g/cm3, phase transformation temperature at 642,5oC, thermal expansion coefficient in range of 30 to 642,5oC (of tetragonal) is 25,9.10-6.K-1, in range 642,5 to 946,8oC is 9,3.10-6.K-1 (of cubic).