Abstract: Antimony pentachloride is recovered from a spent antimony catalyst mixture in a simple manner by bubbling through the spent catalyst mixture an inactive gas such as trichlorotrifluoroethane at an elevated temperature to convert and to remove high melting point or high sublimating point substances as lower boiling point substances; converting fluorinated antimony into chlorinated antimony by means of a chlorinating agent such as carbon tetrachloride; converting antimony (III) into antimony (V) by oxidation with chlorine; and recovering antimony pentachloride by distillation. The antimony pentachloride thus recovered may readily be used as a catalyst for fluorination of a chlorinated hydrocarbon by reaction with hydrogen fluoride.