Reactor design for nickel recovery from HDS waste catalyst

In Mexico, many tonnes of nickel from waste petrochemical catalysts are dumped every year. In order to recover all that nickel, a hydrometallurgical reactor was designed. This design was performed in a systematical fashion, which included the chemistry of the system under study, both a kinetic and mass transfer study, and finally the use of the RTD function, to optimize the reactor size. It was found that the NiO leaching with sulfuric acid is well represented by a first order reaction. The mass transfer results are in good agreement with the experimental results, obtaining over 95% nickel extraction in both cases. A marketing study was also completed that determined that it is possible to make a good profit by processing this residue provided the capital cost was low.