What role does petroleum coke play in converting titanium dioxide to titanium tetrachloride?

In the carbo-chlorination process used to convert titanium dioxide (${\text{TiO}}_2$) into titanium tetrachloride (${\text{TiCl}}_4$), petroleum coke serves as a critical reactant within a fluidized bed.1

The process functions as follows:
* Chemical Reaction: The oxide ores are reacted with chlorine in the presence of the petroleum coke. The carbon (C) in the coke reacts with the oxygen from the titanium dioxide to produce carbon monoxide (CO) and carbon dioxide (${\text{CO}}_2$).1
* Facilitating Conversion: This reaction allows the titanium to combine with chlorine to form gaseous ${\text{TiCl}}_4$.1
* Operational Role: The petroleum coke provides the necessary carbon to strip oxygen from the titanium ore, enabling the chlorination to proceed at temperatures typically ranging between 850 and 1,000 °C (1,550 and 1,800 °F).1

Following the reaction, the raw ${\text{TiCl}}_4$ is cleaned of any entrained particles of coke and titanium ore before undergoing further purification through distillation. This method is essential for producing the high-purity ${\text{TiCl}}_4$ required for the subsequent extraction of titanium metal.12