Preparation of Titanium Powder by Reduction of TiO₂ at Low Temperature with CaH₂

A new method for preparing Ti powder by thermal reduction at low temperature was explored with industrial titanium dioxide（TiO₂） powder and AR（Analytical Reagent） calcium hydride（CaH₂）powder as raw materials.The decomposition conditions of CaH₂ and the process for reduction of TiO₂ by decomposed CaH₂ were studied by reaction thermodynamics calculations and experiments.The results show that vacuum conditions can reduce the decomposition temperature of CaH₂,and CaH₂ is decomposed into Ca and H₂ at 890.7 K for 1 h with 2.5 Pa of initial vacuum degree.TiO₂ is stepwise reduced by Ca decomposed from CaH₂,and the intermediate products such as Ti_nO_{2 n-1} and CaTiO₃can be finally reduced into Ti at temperatures higher than 993 K for 3 h.H residual in Ti powder can be efficiently removed by distilling the products at reaction terminal.The obtained Ti powder is of irregular block shapes with a median size of 1.83 μm,satisfying the composition requirements for TF-2 grade of Ti powder according to the industrial standard YS/T 654-2007.