Reaction Behavior and Conversion of Anatase in Alumina Production Process with Calcification-Carbonization Method

Abstract

The reaction behavior and conversion of anatase in the calcification-carbonization process were investigated experimentally in the pure substance systems of Na2O-Al2O3-CaO-TiO2-H2O and Na2O-Al2O3-SiO2-CaO-TiO2-H2O. The calcification experiments were conducted respectively in the digestion conditions of diaspore and gibbsite. In calcification process, with temperature increasing, anatase converts to firstly Ca3TiSi2(Al2Si0.5Ti0.5)O14 and then CaTiO3. The increase of sodium aluminate solution concentration and additive TiO2-SiO2 ratio can promote this conversion. In carbonization process, CO2 can't make CaTiO3 decompose. CaTiO3 is the most stable titanate phase in calcification-carbonization process.