Recovering metal compounds from used catalysts obtained from hydroprocessing hydrocarbon feedstocks

Abstract From the Canadian patent

A process for recovery of valuable metals such as principally nickel and vanadium deposited on used catalyst from catalytic hydroprocessing of hydrocarbon metals-containing feedstocks. In the process, the used catalyst containing metals deposits is treated with a fresh dilute acid solution such as sulfuric acid to extract and remove the metals deposits without damage to the catalyst, after which the resulting spent acid solution containing metal salts is neutralized to a pH of about 3.5-12 with a hydroxide solution sufficient to form a metal salts precipitate material. The precipitate material is removed from the liquid such as by filtering, and the precipitate is then heated to evolve …