Method of purifying zirconium tetrachloride and hafnium tetrachloride in a vapor stream

摘要

A vapor stream from a sand chlorinator containing principally zirconium tetrachloride, hafnium tetrachloride and silicon tetrachloride contaminated with ferric chloride is purified by cooling the vapor to a temperature of about 335 DEG C. to about 600 DEG C. The cooled vapors flow through a gaseous diffusion separative barrier where a silicon tetrachloride vapor stream contaminated with metal chlorides flows from the separative barrier as a "fast" stream; ferric chloride is adsorbed by the separative barrier; and a vapor stream principally containing zirconium tetrachloride, hafnium tetrachloride and silicon tetrachloride is screened by the separative barrier.