Abstract: Thermodynamic and kinetics analysis of anatase TiO₂ reaction in high calcium system were conducted and the possible reactions were determined. Activation energy， reaction order and reaction control types of important reactions were determined by calculation in this system. The reaction behaviors of anatase TiO₂ in TiO₂-CaO-NaAlO₂ system were investigated through experiments. The results showed that when the molar ratio of TiO₂ and CaO is 1， the reaction time is 1h， the mass concentration of Na₂O is 220g/L， the molar ratio of Na₂O and Al₂O₃ is 3.1， TiO₂ reacts with NaOH to produce Na₂TiO₃ first， then Ca(OH)₂ and NaAl(OH)₄ react to produce 3CaO·Al₂O₃·6H₂O with increasing temperature. The resultant 3CaO·Al₂O₃·6H₂O reacts with Na₂TiO₃ to get stable CaTiO₃. Anatase TiO₂ converts to CaTiO₃ completely at 220℃. In this process， elevating temperature can promote the conversion of anatase to the final phase of CaTiO₃.

Key words: alumina, anatase, reaction behavior, high calcium, temperature