Sintering process of the heat treated product of the synthesized magnesite at temperatures between 450° and 1500°C with the intervals 100°C in air and the resulting materials were studied by the X-ray powder diffraction and scanning electron microscopy.
It was found that the product at 600°C was identified as periclase and these small magnesia particles began to sinter each other with increasing rapidity at about 1100°C. The pseudorhombohedral shape of the magnesite was almost retained after it was heated at 1500°C.
The particles of the magnesia increased in size and the lattice dimension decreased with increasing temperatures. High preferred orientation of the magnesia crystallite with respect to the original magnesite was revealed from electron diffraction and X-ray oscillation photograph.