Patent ID: 6673732
Filing Date: 2004-01-06
Classification: B01J,C01C,C22B,Y02P,Y10S

Abstract:
Process for the recovery of catalytic components from an ammonia synthesis catalyst comprising ruthenium as a catalytically active metal promoted with one or more components selected from the groups of alkali metals, alkaline earth metals and lanthanides, the catalytically active metal being supported by a magnesium oxide material, wherein the magnesium oxide material has a specific surface area of at least 40 m2/g, the ruthenium concentration is between 3 wt % and 20 wt % and the promoter content is between 0.2-5.0 mole of promoter per mole of ruthenium, the process comprising the steps of:a) Washing the promoters off the catalyst with a basic solvent thus forming a promoter-depleted catalyst, and obtaining a solution rich in dissolved promoter hydroxides; b) dissolving the magnesium oxide from the promoter-depleted catalyst in an acidic solvent in which ruthenium is not soluble, thus obtaining a ruthenium metal remnant in a solution rich in the dissolved magnesium compound; and c) recovering the ruthenium metal remnant from the solution rich in the dissolved magnesium compound by means of liquid-solid separation, thereby obtaining said solution rich in the dissolved magnesium compound, and ruthenium metal.