| abstract |
Provided is a process for recovering high-purity, nickel, cobalt, molybdenum, and vanadium from a waste catalyst by a simple means in a high yield. The process comprises the step of heating a waste catalyst containing valuable metals in a non-oxidizing atmosphere to deoil the waste catalyst via the pyrolysis of adhering oil, the step of co-pulverizing the deoiled waste catalyst and a chloride to form chloride of nickel and/or cobalt, the step of leaching the co-pulverized waste catalyst with water to dissolve nickel and/or cobalt in water, the step of oxidizing the obtained leach residue, which remains after the water leaching and contains molybdenum and/or vanadium, to form oxide of molybdenum and/or vanadium, and the step of subjecting the resulting leach residue, which contains oxide of molybdenum and/or vanadium, to alkaline leaching to dissolve molybdenum and/or vanadium in an alkaline solution. |