Leaching of vanadium from spent sulphuric acid catalysts

Recovery of vanadium contained in spent catalysts from the manufacture of s ulphuric acid has been studied, resulting in an industrial multistage proce ss avoiding direct deposition or dumping. Characterization of spent catalys t samples supplied confirmed vanadium levels given in the literature. The s tudy of variables influencing the leaching process: leaching agent concentr ation, sn ratio, stirring speed and temperature, allowed more advantageous industrial conditions to be determined and verified that the process is dif fusion controlled. The work was completed by developing an industrial leach ing cycle simulation with the aim of reproducing the real performance of sp ent catalyst, proposed operating conditions, and verifying that the final r esidue obtained was not toxic. (C) 2001 Elsevier Science Ltd. All rights re served.