To provide a chlorination treatment method for waste catalysts ensuring high-purity vanadium tetrachloride to be recovered in high yield from the waste catalysts, and to provide a method for isolating vanadium tetrachloride from a reaction product obtained from waste catalysts.
This method for recovering vanadium from waste catalysts containing both vanadium and sulfur comprises the following consecutive steps: a chlorination process which is conducted in a reactor 12 comprises chlorinating a waste catalyst with a chlorinating agent under a pressure exceeding the atmospheric pressure at 100-350°C without burning it and without chlorinating a catalyst carrier and the metal carried thereon to produce a mixed vapor composed of vanadium tetrachloride and sulfur dichloride; a condensation process which is conducted in a condensation arrangement 14 comprises cooling the above mixed vapor to effect condensation into a mixed liquid composed of vanadium tetrachloride and sulfur dichloride; and the final process which is conducted in a distillation arrangement 16 comprises subjecting the above mixed liquid to distillation by pressure distillation method with an overhead pressure of 5-15 kg/cm-2 to respectively issue a sulfur dichloride liquid from the distillation column overhead and a vanadium tetrachloride liquid from the bottom.
MAEJIMA TETSUO
KAWASE TAKEO
ENDO SHIGERU
KAERUISHI KENICHI
