Injection Technology To Recover Nickel And Cobalt From Spent Catalysts

The petroleum refining industry generates over a million tons of spent catalyst per year, containing valuable metals. Currently, these materials are recycled to smelting furnaces, but the fundamental mechanisms controlling the recovery processes are poorly understood. Furthermore, submerged injection of finely divided materials is potentially a means to obtain high recoveries of pay metals. In this study, a catalyst containing 10% Ni and 1% Co was injected into 45 kg heats of matte. A copper matte was chosen so that the nickel and cobalt recoveries were measurable. It was found that the recovery ranged from 40 to 700Al, increasing with catalyst feed rate, decreasing with catalyst particle size and decreasing with the oxygen content of the carrier gas. A mathematical model was developed to account for the results, and to permit extrapolation to nickel mattes. The industrial implications are discussed.