Selective recovery of metals from spent desulfurization catalyst

Valuable metals including V, Mo, Ni, Co, and Al were selectively recovered from spent desulfurization catalyst by means of extractive separation. Prior to selective metal recovery the spent catalyst was roasted at temperatures of 400–800 °C, and BET, SEM, and XRD data showed that roasting the spent catalyst at 550 °C gave birth to the surface and pore structures accounting for good extractibility of the roasted spent catalyst. A sequential scheme consisting of leaching and chelate extraction was developed to recover the metals from the spent catalyst roasted at 550 °C and oxygen space velocity of ca. 1800 hr⁻¹.