Optimization Research on Vacuum Distillation Process for Titanium Sponge Preparation by Magnesium Thermal Reduction

According to the technology problems of the intermediate channels blockage in distillation process and the over standard of chloridion in products during the titanium sponge production by magnesium thermal reduction,the optimizations of system pressure,temperature and time in distillation process were conducted.Thermodynamic analysis results show that the relative volatility of Mg and MgCl₂ to Ti is more than 2.21 x 10¹¹ when the distillation temperature is 900~1 000℃.Distillation process optimization experiments show that the favorable system pressure of vacuum distillation process is not more than 4 Pa,and the preheating temperature is 750~800℃,the early stage of the preheating time 1~2.5 h and continuous water spray time in the initial distillation process 30~36 h.After the optimizations,the product grade rate of titanium sponge improves significantly,and the titanium sponge above grade 0 increases by 16.54% on average while the ratio of substandard titanium decreases by 6.4%.