Process for extracting metals from spent desulphurization catalysts

Claim 1

A process for the extraction of vanadium and molybdenum from a spent desulfurization catalyst containing the same, and having an aluminum oxide carrier, said spent catalyst not having been subjected to previous oxidative roasting, comprising the steps of: (a) intimately admixing comminuted spent catalyst with an amount of a solid alkali metal carbonate sufficient to convert the vanadium, molybdenum, and any sulfur which may be present, into water-soluble compounds; (b) heating the mixture produced in step (a) in the solid state in the presence of air at a temperature between about 650° C and about 850° C for a period between about 1 and about 2 hours; and (c) leaching the product of step (b) with water to dissolve the vanadium and molybdenum compounds and recovering said compounds from the extract; the amount of solid alkali metal carbonate also being sufficient so that the extract of step (c), after filtration, has a pH higher than 7.5 but lower than 10.0.