The effects of carbon/slag molar ratio, chloride amount and temperature on equilibrium molar ratio (REq) of CO to CO2 for off-gas produced by carbochlorination of titanium slag were firstly investigated by thermodynamic calculation of equilibrium components of off-gas. The experimental CO/CO2 molar ratio (REx) was then obtained to be 0.2-0.3 by the carbochlorination experiment using a novel combined fluidized bed as chlorination reactor. To further investigate the reaction effect of the novel process mentioned above, REx, REq and corresponding reference data (RRe) were compared. The results indicate that REx is similar to RRe (0.5-1.2) but different from REq (≥4.3), which is consistent with anticipation of REx for the novel combined fluidized bed. The difference between REx and corresponding REq is mainly attributed to short retention time (about 1 s) of materials in combined fluidized bed and carbochlorination of oxide impurities contained in titanium slag, such as CaO, MgO and SiO2.
To fully utilize Panzhihua titanium resources, a new process was proposed. In the process, Panzhihua ilmenite concentrate was first reduced in a rotary hearth furnace (RHF) to produce a titanium-rich material and iron. The titanium-rich material was then used in a new chlorination process to produce TiCl4. The comparison of different groups of experimental results or calculation results showed that the utilization ratio of material was improved by using the titanium-rich material after pretreatment other than low level titanic ilmenite directly and the combined fluidized beds (FTF) were more likely to reduce bed height and reaction time than the single fluidized beds (Single F or Single T) under the condition of the same chlorination conversion ratio. Finally, the influence of reduction temperature and the anti-agglomeration capacity of the combined fluidized bed was analyzed.