Investigations on a novel process to recycle valuable metals from spent Al2O3-based catalyst

Based on X-ray phase analysis and exploratory experiments, a novel process was proposed to recycle multiple valuable metals like Al, V, Mo, Ni and Co from spent Al2O3-based catalyst. The spent catalyst was roasted by adding sodium carbonate with certain mol ratio, after water leaching, Al, V and Mo could be extracted into leach liquor, whereas Ni and Co were enriched in the leaching residue. V and Mo were precipitated in step from leach liquor by adding CaO and BaAl2O4, respectively. After removal of V and Mo, Al(OH)(3) was prepared from sodium aluminate solution with carbonation decomposition process, and the purity of Al2O3 is 99.98%. With sodium bicarbonate leaching-purification-precipitation-calcination process, V2O5 could be prepared from V-bearing residue. Ni and Co were leached from water leaching residue with sulfuric acid. Recoveries of Al, V, Mo, Ni and Co from spent catalyst are 87.0%, 88.7%, 92.1%, 97.8% and 98.6%, respectively.