Recovery of titanium from the slurry formed in crude TiCl_4 by reactive distillation with NaCl-AlCl_3 and recycling of NaCl-AlCl_3 by vacuum distillation

摘要

The recovery of titanium from the slurry formed in crude titanium tetrachloride and recycling of NaCl eAlCl_3 was studied. Experimental results showed that the titanium contained in the slurry can be effectively recovered by reactive distillation with molten NaCl-AlCl_3. More than 99% of titanium was volatilized from the slurry by distilling at 453 K for 40 min with slurry to molten salt (S/M) ratio of 1.8:1. Experiments found that the recovered titanium includes the chloride and oxychloride as the TiOCl_2 containing in the slurry was changed into TiCl_4 by the complex reactions of TiOCl_2 with AlCl_3 and NaAlCl_4 during reactive distillation. The behavior of molten NaCl-AlCl_3 during vacuum distillation was studied and NaCl-AlCl_3 was recovered from the reactive distillation residue (RD residue) by vacuum distillation. The study showed that high temperature and vacuum were favorable to the evaporation of NaCl-AlCl_3. Meanwhile, 97.8% of AlCl_3 and 66.8% of NaCl were recovered from RD residue as distillate. The distillate was a mixture of AlCl_3 and NaAlCl_4, which can be returned to reactive distillation by adding a small amount of NaCl.