Recycling titanium from Ti‐waste by a low‐temperature extraction process

Abstract In the commercial chloride process, titanium is extracted from Ti concentrates at high temperatures (800–1,500°C), and the high‐purity rutile is the primary raw material. Chlorination at high temperatures results in high‐energy consumption, rapid corrosion of equipment, pipelines and control system, and agglomeration of the solid bed by the liquid byproducts. The high‐purity rutile is expensive and its natural deposit is being depleted. Therefore, a low‐temperature Ti extraction process using Ti‐waste as the primary raw material is highly desirable. Thermodynamic equilibrium simulation of the reaction system shows that the extraction of Ti from Ti waste is feasible at a temperature as low as 200°C. In this study, a simple technology was used to remove diffusion barriers, and a low‐temperature chloride process was developed. The chlorination reaction operates at 300–350°C, and Ti‐waste can be used to replace the expensive rutile. Up to 80% of the titanium can be recycled in 5 min at 350°C. The extraction of other components has a relatively low extent, so a selective extraction of Ti can be achieved. A fluidized‐bed reactor was used for the chlorination process. The formation of an activated TiO2–C–Cl complex on the TiO2/C interface accounts for the gas‐solid‐solid reaction mechanism.