The alkalyne leaching of spent alumina-based catalysts from the petroleum industry, containing molybdenum and/or vanadium among other metals, yields a solution rich in Mo(VI), V(V) and Al(III). In order to recover the two heavy metals aluminum must be first quantitatively separated. Several routes were theoretically tested by computer simulation. Finally, the extraction of aluminum with oxine was chosen. A commercial reagent similar to oxime, LIX 26 (Henkel), was used. The extraction of the three metals with several organic phases containing LIX 26 /n-octanol /hexane was systematically studied.|The best separation conditions were found to be 7<pH<8, 0.3% LIX 26 and 10% n-octanol. A two step counter-current extraction with equal volumes of the two phases gives 99.6% extraction of Al(III) with less than 1 ppm of Mo(VI) and V(V). The organic phase can be regenerated by contacting with sulphuric acid, at pH<2, where aluminum is quantitatively stripped.