Carbochlorination of Low-Grade Titanium Slag to Titanium Tetrachloride in Molten Salt

Thermodynamic analysis and experiments were conducted in order to verify the feasibility of preparing crude titanium tetrachloride (TiCl₄) via the carbochlorination of low-grade titanium slag in molten salt. Titanium slag, assaying 74.6 wt% TiO₂ with high calcium and magnesium oxide impurities, was treated by an optimized carbochlorination process in NaCl molten salt. These impurities in the titanium slag were chloridized simultaneously, and chlorination products FeCl₂, MnCl₂, MgCl₂, CaCl₂ and CrCl₃ were collected in the furnace slag. XRD and SEM/EDS analysis of residue shown that SiO₂ and Al₂O₃ in titanium slag were difficult to chlorinate completely. Theoretical calculations and industrial-scale experimental studies reveal the content of TiCl₄ in the products was more than 98.8 wt% and thus proved the feasibility of utilizing low-grade titanium slag for TiCl₄ preparation by molten salt chlorination technology.