Metal recovery and rejuvenation of metal-loaded spent catalysts

Metal recovery and/or rejuvenation technologies of the spent catalysts resulting from various sources are reviewed. The fluid cracking catalyst (FCC), resid fluid cracking catalyst (RFCC), hydrodesulfurization (HDS) catalyst, supported and unsupported precious metal containing catalysts, i.e., reforming catalyst, auto catalyst and other catalysts from a variety of industrial processes are targeted. The precious metal recovery technologies such as the processes using aqua regia, chlorination, segregation and Rose (metallurgical) method are discussed in detail. A series of the FCC demetalation/regeneration processes such as Met-X, Demet, Demet II, Demet III and Demet IV is also described from the view point of the developmental history. Two physical processes using the high gradient magnetic and density grading separator are also reviewed.