The Influences of Sintering Systems on Microstructure of Anorthite Light Heat Insulation Refractory Materials

The magnesium slag, kaolin and alumina as raw material, sinter anorthite lightweight insulating refractory. The paper studied firing temperature and holding time affecting the sample microstructures. The results showed that: the new crystalline phases are mainly anorthite and alumina. With increasing temperature, grains increases which are mainly plate-like bodies and cylindrical bodies. At the same time, with the temperature grains grow up from 1 μm to 10 μm, aggregates increases, porosity increases and isolated. 1350˚C - 1370˚C are the appropriate sintering temperatures with grains size in the 2 - 5 μm, volume density 1.52 g/cm 3 and the rate of open pores 60%. In 1370˚C temperature, with holding time changing, grains size does not change after the 5 μm, but the bond formed by the aggregate grains gradually from large to small and uniformity, along with uniform pores, volume density 1.50 - 1.53 g/cm 3 and the rate of open pores 57% - 60%.