Mechanism of Scaling on the Oxidation Reactor Wall in TiO2 Synthesis by Chloride Process

The formation of wall scale was mostly due to being deposited and sintered of TiO2 particles formed in the gas phase reaction of TICl4 with O-2. The gas phase oxidation of TiCl4 was in a high temperature tubular flow reactor with quartz and ceramic rods put in center respectively. Scale layers were formed on reactor wall and two rods. Morphology and phase composition of them were characterized by scan electron microscopy and X-ray diffraction. The state of reactor wall has little effect on scaling formation. With uneven temperature distribution along axial of reactor, the higher the reaction temperature is, the thicker the scale layer and the more compact the scale structure is.