An integrated process for the recovery of metals and fused alumina from spent catalysts

摘要

An integrated process for the treatment of spent catalysts containing mainly molybdenum, vanadium, nickel, cobalt and, alumina to produce ammonium metavanadate, vanadium pentoxide, molybdic trioxide, fused alumina and a high grade nickel/cobalt alloy essentially free of aluminum. Spent catalysts are first subjected to roasting in the presence of a sodium salt such as Na2 CO3 to convert Mo and V into their soluble sodium salts. The roasted material is leached with water to obtain a solution laden with Mo and V and a residue containing all the alumina, nickel, cobalt and a portion of the molybdenum and vanadium and some sodium. The leach solution is chemically treated to separate vanadium and molybdenum values. The leach residue is dried and reduced with carbon in an electric furnace to produce a high grade Ni/Co alloy and fused alumina substantially free of sodium.