Influence Factors Analysis on Scavenging of Chlorine Impurity from Crude Titanium Sponge

Titanium is exceptional value to industry, military and consumer applications due to the attractive combination of properties exhibited by metallic titanium and its alloys. The Kroll reduction reaction is a complex heterogeneous exothermic reaction with the possibility of the formation of TiCl2 and TiCl3 as reaction intermediates. Chlorine impurity has been a significant technical challenge in titanium production ever since the inception of the Kroll processes themselves. In this investigation, an attempt was made to check the influence factors of titanium sponge structure, raw materials, times of distillation and vacuum distillation process parameters on chorine impurity scavenging. The results indicate that the decrease of Ti sponge porosity increased the difficulty of chloride impurities removing. Chlorine content increased rapidly from 0.012 to 0.121% when the system pressure grew from 0.1 to 12 Pa in the vacuum distillation process. The chlorine content in titanium sponge was also increased with the increase of NaCl, MgCl2 and CaCl2 impurities in Mg reductant.