Decomposition kinetics of titanium slag in sodium hydroxide system

A novel process was proposed for preparing titanium dioxide by the decomposition of titanium slag in sodium hydroxide system under atmospheric pressure. The kinetics on the decomposition of titanium slag was mainly investigated. The results on effect of reaction temperature, particle size and NaOH-to-slag mass ratio on titanium extraction show that the temperature and particle size have significant influence on the titanium extraction. The experimental data of titanium extraction indicate that the shrinking core model with chemical reaction controlled process is most applicable for the decomposition of titanium slag, with the apparent activation energy of 40.8 kJ mol(-1). Approximately 95-98% of titanium in the titanium slag could be extracted under the optimal reaction conditions. In addition, the content of TiO2 obtained in the product is up to 99.3%. (C) 2008 Elsevier B.V. All rights reserved.