Leaching of vanadium from spent sulphuric acid catalysts

Recovery of vanadium contained in spent catalysts from the manufacture of sulphuric acid has been studied, resulting in an industrial multistage process avoiding direct deposition or dumping. Characterization of spent catalyst samples supplied confirmed vanadium levels given in the literature. The study of variables influencing the leaching process: leaching agent concentration, S/L ratio, stirring speed and temperature, allowed more advantageous industrial conditions to be determined and verified that the process is diffusion controlled. The work was completed by developing an industrial leaching cycle simulation with the aim of reproducing the real performance of spent catalyst, proposed operating conditions, and verifying that the final residue obtained was not toxic.