Effective extraction of titanium from rutile by a low‐temperature chloride process

Abstract

AbstractThe carbochlorination of rutile is carried out at high temperatures (800–1,500°C) in the commercial chloride processes of the pigment industry. Chlorination at high temperatures results in high energy consumption, rapid corrosion of the equipment, pipeline and control system, and agglomeration of solid reactants in the reactor. In a typical chloride process, rutile is used as a primary reactant, Cl2 as a chlorinating agent, and carbon as a reductant. The thermodynamic equilibrium simulation of the reaction system shows that a complete conversion of rutile is feasible at a temperature as low as 200°C. Kinetic and diffusion barriers, however, make the reaction practically impossible at low temperatures. In the study, these barriers were removed by intensifying the rutile‐carbon solid–solid contact. In the low‐temperature chloride process developed, reaction temperatures are reduced to 350–450°C. The conversion rate of the rutile at 385°C is 30% higher than that at 1,000°C. A fluidized‐bed reactor was used for the chlorination process. It was concluded that the formation of an activated TiO2CCl complex on the TiO2/C interface accounts for the gas–solid–solid reaction mechanism.