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AssigneeDirector-General of Agency of Industrial Science and Technology
InventorNaganori Rokukawa
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The invention provides a novel method for selectively recovering molybdenum nd vanadium values from a spent catalyst used for the hydrogenation desulfurization of petroleums by the extraction with an alkaline extractant solution without the necessity of preliminary calcination of the spent catalyst containing, in addition to the molybdenum and vanadium values, nickel, cobalt and other heavy metals as well as sulfur and carbonaceous matters as the contaminants supported by or deposited on an alumina carrier. The inventive method utilizes an aqueous alkaline solution of sodium carbonate with admixture of hydrogen peroxide as an oxidizing agent whereby an unexpectedly high percent extraction is obtained for the molybdenum and vanadium values reaching 99% or higher for the former and about 85% for the latter while the extraction of nickel, cobalt and aluminum can be minimized.
A method for selectively recovering molybdenum and vanadium values from a spent catalyst used for the hydrogenation desulfurization of petroleums containing molybdenum, vanadium, nickel and cobalt values supported by or deposited on an alumina catalyst carrier which comprises (a) suspending and agitating the spent catalyst in an aqueous extractant solution of sodium carbonate and hydrogen peroxide to effect selective extraction of the molybdenum and vanadium values into the aqueous solution and (b) separating the aqueous solution from the undissolved residue.
Dependencies are inferred from the claim text.