RECOVERING METALS FROM SPENT HYDROPROCESSING CATALYSTS

摘要

OF THE DISCLOSURE A method of stripping an organic extraction solvent containing extracted metal constituents selected from the class consisting of Group Vb and Group VIb metals of the Periodic Table and quaternary alkyl ammonium comprising: contacting said organic extraction solvent with an aqueous stripping solution maintained at a temperature of not more than 50.degree.C, a pH of between 7 and 9, and containing at least 75 grams per liter of a salt of a bicarbonate ion, for a time sufficient to convert said metal quaternary alkyl ammonium complexes to aqueous soluble metal complexes; separating said organic extraction solvent and said aqueous stripping solution. This stripping method finds use in the recovery of Group Vb and Group VIb metals in solvent extraction processes used to treat spent hydroprocessing catalysts.