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.