Process for recovering vanadium accumulated on spent catalyst

Abstract From the Canadian patent

This invention relates to a process for selectively recovering vanadium from spent catalysts which were used in hydrodesulufurization, hydrodemetallization etc. of heavy oils, until metals in said heavy oils accumulated thereon. More particularly it relates to a process for recovering vanadium, and if desired, vanadium along with nickel from spent catalysts in such a way that said spent catalysts are chlorinated with chlorinating agent(s) at a temperature below 600°C without being subjected to calcination so as to convert almost all the vanadium compounds to vanadium tetrachloride which is recovered in the form of a gas, including the chlorination of nickel compounds to nickel chloride …