Sintering of anorthite ceramic body based on interstratified illite-smectite clay

The effects of the different properties of plastic raw materials for whitewares based on different clay minerals (kaolinite vs interstratified illite/smectite [I/S]) on the sintering process (according to vacuum water absorption) was studied for anorthite porcelain body creation after firing in the range of 950–1500 °C to achieve optimal sintering temperature. The mineralogical composition of the fired bodies was observed from the firing temperature of 950 °C to the sintering temperature. Calcium carbonate decreases the sintering temperature and creates a new mineralogical phase in the fired body – anorthite – which decreases the linear thermal expansion coefficient and increases the strength (modulus of rupture) of the sintered bodies. All the described effects take place at lower firing temperatures when the I/S plastic raw material is compared with kaolin.