Investigation of the mineral components of porcelain raw material and their phase evolution during a firing process by using a Rietveld quantitative analysis

A ceramic raw material for white porcelain and its phase evolution during a firing process were investigated by using Rietveld method based on powder X-ray diffraction data. The raw material was mainly composed of five mineral phases: quartz (SiO 2 ), microcline (KAlSi 3 O 8 ), albite (NaAlSi 3 O 8 ), muscovite (KAl 2 (AlSi 3 O 10 )(OH) 2 ), and kaolinite (Al 2 Si 2 O 5 (OH) 4 ). The amount of each mineral phase could be determined by using Rietveld quantitative phase analyses. During the firing process, the microcline, albite, muscovite and kaolinite phases started to react with each other to produce the mullite phase embedded in an amorphous matrix. The amount of quartz remained nearly unchanged until a temperature above 1200 °C; then, it converted to an amorphous phase at higher temperatures.