摘要 |
A method for recovering vanadium from a spent slurry catalyst for hydrocarbon oil hydroprocessing is disclosed. In one embodiment after de-oiling, the spent catalyst is treated with ammonia and air, forming a leach slurry. The leach slurry is subsequently treated with a flocculant. After solid-liquid separation to recover the solid residue containing coke and ammonium metavanadate, the solid residue is washed with an ammonium sulfate solution and leached with hot water. After solid-liquid separation to recover a solution containing ammonium metavanadate, the ammonium metavanadate is crystallized and purified from the leach solution. |