Purification of refractory metals

Claim 1

A PROCESS FOR REMOVING A BY-PRODUCT SALT CONTAMINANT FROM A SOLID REFRACTORY METAL REACTION PRODUCT RECOVERED FROM THE REDUCTION OF A METAL HALIDE WITH A REDUCING METAL, COMPRISING CHARGING SAID REACTION PRODUCT UPWARDLY AND IN INTERMITTENT STAGES THROUGH A CLOSED, ELONGATED TREATING CONDUIT INCLINED AT AN ANGLE FROM THE HORIZONTAL AND FROM AN INLET TO A DISCHARGE OUTLET OF SAID CONDUIT, DURING ITS PASSAGE THROUGH SAID CONDUIT HEATING SAID REACTION PRODUCT, UNDER SUBSTANTIALLY ATMOSPHERIC PRESSURE, TO A TEMPERATURE ABOVE THE MELTING POINT OF SAID SALT CONTAMINANT BUT BELOW THE THE MELTING POINT OF THE METAL COMPONENT PRESENT IN SAID REACTION PRODUCT, REMOVING SAID BY-PRODUCT FROM SAID REACTION PRODUCT AND THE SYSTEM DURING SAID HEATING AND WHILE SAID PRODUCT IS BEING SUCCESSIVELY PASSED THROUGH MELTING, DRAINING AND VAPORIZATION ZONES MAINTAINED IN SAID CONDUIT, MAINTAINING A COUNTERFLOW OF AN INERT GAS OVER THE REACTION PRODUCT DURING ITS TREATMENT IN SAID VAPORIZATION ZONE AND FLOWING SAID GAS FROM SAID VAPORIZATION ZONE INTO AND THROUGH SAID MELTING AND DRAINING ZONES, AND PRIOR TO DISCHARGE OF THE RESULTING PURIFIED METAL PRODUCT FROM SAID CONDUIT COOLING IT TO A NON-REACTIVE TEMPERATURE.