Process for regeneration of antimony halide catalysts

Abstract

Abstract Spent antimony halide catalysts resulting from the fluorination of chlorinated hydrocarbons and containing in the spent condition a mixture of antimony (III)- and antimony (V)-halides are regenerated by A. DISSOLVING THE SPENT CATALYST IN WATER TO FORM AN AQUEOUS ACIDIC SOLUTION THEREOF; B. ADDING A CONCENTRATED SOLUTION OF AMMONIA TO SAID AQUEOUS SOLUTION UNTIL THE SOLUTION IS SLIGHTLY ALKALINE AND MAINTAINING THE SOLUTION AT THE RESULTING INCREASED TEMPERATURE UNTIL THE ANTIMONY OXIDES ARE PRECIPITATED FROM THE SOLUTION, FORMING A SUSPENSION THEREIN; C. FILTERING OFF THE PRECIPITATE; D. DISSOLVING THE PRECIPITATE IN CONCENTRATED HYDROCHLORIC ACID; E. INTRODUCING SULFUROUS ACID, A SALT THEREOF OR SODIUM THIOSULFATE INTO THE SAID SOLUTION, WHILE ADDING A REDOX CATALYST IN CASE OF SULFUROUS ACID OR SALT THEREOF, SO AS TO CAUSE REDUCTION OF THE ANTIMONY (V)-chloride present in said mixture of antimony chlorides to antimony (III)-chloride; F. ADDING A CONCENTRATED AQUEOUS AMMONIA SOLUTION TO THE HYDROCHLORIC ACID SOLUTION TO PRECIPITATE THE ANTIMONY COMPOUND IN THE FORM OF ANTIMONY (III)-oxide or antimony (III)oxychloride; G. SEPARATING THE WEB PRECIPITATE FROM THE SOLUTION; H. DISSOLVING IT IN CONCENTRATED HYDROCHLORIC ACID, AND I. SUBJECTING THE HYDROCHLORIC ACID SOLUTION TO FRACTIONAL DISTILLATION TO OBTAIN ANTIMONY (III)-chloride which can be used as fresh catalyst in the above fluorination reaction. If the fluorine ion contents of the spent catalyst is not in excess of 1 percent, the reduction may be performed directly with the aqueous acidic solution of the catalyst without alkalizing the solution with ammonia solution and dissolving the precipitate in hydrochloric acid.

Inventors

• 👤 W Becher
• 👤 J Massonne
• 👤 W Pohlmeyer

Bibliographic Details