Procedure and apparatus for subhalide refining of aluminum

Claim 1

A PROCESS FOR SEPARATING GASEOUS IMPURITY, OF PERMANENT GAS, FROM A FLOW OF ALUMINUM TRICHLORIDE GAS CONTAINING SUCH IMPURITY, COMPRISING ADVANCING SAID FLOW INTO A CONDENSING REGION AND THERE CONDENSING ALUMINUM TRICHLORIDE BY ABSORPTION IN A MOLTEN SALT MIXTURE CONTAINING ALUMINUM TRICHLORIDE, AT A TEMPERATURE OF SAID MIXTURE FOR A ABSORPTION OF ALUMINUM TRICHLORIDE THEREIN, WHILE WITHDRAWING THE UNCONDENSED REMAINDER OF SAID FLOW, COMPRISING SAID GASEOUS IMPURITY, FROM SAID REGION, AND THEREAFTER HEATING SAID ALUMINUM TRICHLORIDE-ENRICHED MOLTEN SALT MIXTURE TO EVAPORATE ALUMINUM TRICHLORIDE THEREFROM, FOR REESTABLISHING SAID ALUMINUM TRICHLORIDE IN GASEOUS FORM, PURIFIED WITH RESPECT TO SAID IMPURITY, SAID EVAPORATION OF ALUMINUM TRICHLORIDE FROM THE SALT MIXTURE BEING EFFECTED BY ADVANCING SAID MOLTEN SALT MIXTURE FROM THE CONDENSING REGION TO ANOTHER REGION AND THERE SUPPLYING HEAT TO SAID ENRICHED MOLTEN SALT MIXTURE TO EVAPORATE ALUMINUM TRICHLORIDE, SAID PROCESS INCLUDING COOLING THE MOLTEN SALT MIXTURE AFTER EVAPORATION OF ALUMINUM TRICHLORIDE THEREFROM AND RECIRCULATING SAID MIXTURE TO THE CONDENSING REGION FOR RESPECTED ABSORPTION OF ALUMINUM TRICHLORIDE THEREIN, SAID MOLTEN SALT MIXTURE BEING A MIXTURE WHICH CONSIST ESSENTIALLY OF ALUMINUM TRICHLORIDE AND OTHER METAL CHLORIDE, AND WHICH IN MOLTEN STATE IS CAPABLE OF ABSORPTION OF ALUMINUM TRICHLORIDE THEREIN AND OF EVAPORATION OF SAID NORMAL ALUMINUM TRICHLORIDE THEREFROM.