In order to produce low-cost titanium(Ti)with high productivity,fundamental studies on producing metallic Ti from titanium dioxide(TiO2)in the cold pressed pellets were conducted by metallothermic reduction with an indirect contact method.This paper focuses on discussing the mechanism of the reduction process and the relationships of RM(a revised reduction index)with reduction temperature,reduction time,and mole ratio of TiO2 to CaCl2(nTiO2/nCaCl2)in the pellets.The results show that metallic Ti was obtained from the reduction of TiO2 in the pellets by calcium(Ca)vapor;pellets were reduced homogenously and Ca vapor diffused into the porous pellets by Knudsen diffusion or the mixing diffusion of molecular diffusion and Knudsen diffusion at 1273 K;RM increased with the increases of temperature and reduction time and was 96.34%when TRedu=1273 K,tRedu=6 h,and nTiO2/nCaCl2=4;the reasonable nTiO2/nCaCl2 value is 3−5 for the pellets with enough strength and high RM.
