Effect of Calcination Temperature on the Properties of Nanotitania-Based Extrudates from an Industrial Raw Material

Abstract

Titanium dioxide is an important material for catalytic reactions as a promoter, support, catalyst, and additive. In this paper, titania extrudates were prepared from industrial raw material by an extrusion method and then calcined at different temperatures. Results show that there are nanostructures with anatase phase from 450o to 850oC because the presence of SO4 2– delays the formation of rutile nucleation up to 950oC,and the morphology is irregular and smooth at 950oC. The SO4 2– ions and crystallinegrowth affect the properties of titania extrudates at various calcination temperatures. At temperatures below 650oC, the effect of SO4 2–removal is more than the effect of crystalline growth on the properties of the extrudates. But at temperatures above 650oC, the effect of crystal growth is dominant because of mobility of atoms, although more sulfate ions are exited. It decreases open pore volume and increases strength and attrition resistance.