PREPARING TITANIUM POWDERS BY CALCIUM VAPOR REDUCTION PROCESS OF TITANIUM DIOXIDE

摘要

In this paper, thermodynamic equilibrium calculations on the system of Ca-O_2-N_2-TiO_2 were carried out and the calciothermic reduction process of titanium dioxide to prepare titanium powders in the closed graphite vessel was investigated by means of XRD, SEM and EDS. The thermodynamic calculation results indicated that the sum of part pressures of gas O_2 and gas N_2 would equal to 10~(-60)-10 that is much less than the saturated vapor pressure of metal calcium at the same temperature during the range of 298K-1500K in the same system, which implied the metal calcium would become vapor to reduce TiO_2 at certain temperature after exhausting O_2 and N_2 in the closed system.