How is titanium metal extracted from rutile and ilmenite ores?

The extraction of titanium metal from rutile and ilmenite ores is a complex process because titanium is highly reactive and readily forms stable carbides if reduced directly with carbon. Consequently, the industry utilizes a multi-step approach to isolate the metal.1

Chlorination

First, the ores are converted into titanium tetrachloride (${\text{TiCl}}_4$). Because economic and environmental constraints require a high-grade feedstock, rutile is often used directly, while ilmenite is upgraded to synthetic rutile through pyrometallurgical and hydrometallurgical techniques. The ore is reacted with chlorine in a fluidized bed of petroleum coke at temperatures between 850 and 1,000 °C, producing gaseous ${\text{TiCl}}_4$, which is then purified through distillation to remove impurities.21

Reduction

The purified ${\text{TiCl}}_4$ is reduced to metallic titanium using one of two primary methods:
* Kroll process: The ${\text{TiCl}}_4$ is reduced with molten magnesium in a sealed steel vessel under an inert argon atmosphere at approximately 800 to 1,000 °C.31
* Hunter process: The ${\text{TiCl}}_4$ is reduced using sodium.3

Both processes yield a highly porous material known as titanium sponge, which is subsequently crushed and separated from byproduct salts (such as ${\text{MgCl}}_2$ or $\text{NaCl}$) before being fused into ingots.31