Leaching process for extraction of cobalt from spent Co/Al2O3 catalysts

In this work hydrometallurgical route for processing spent commercial catalysts (Co/Al2O3) are investigated for leaching the Cobalt component. The used catalysts were initially pre-oxidized at 500 °C and 5 h in order to eliminate coke and other volatile species present. Pre-oxidized catalysts were dissolved in solvents such as H2SO4, HNO3, HCl and H2O at 80-90 °C, and the remaining residues separated from the solution. These experiments were performed at different concentrations, presence and absence H2O2 solution. Also effect of reflux on leaching process investigated. The result show the yield of the pre-oxidized catalysts extracted with highly concentration of extractant is higher than non pre-oxidation catalysts and also H2O2 is not effective matter for leaching the cobalt. The reflux system is necessary for avoid from volatile solvent and for environmental and economical aspects. All result showed that H2SO4 is suitable solution for cobalt leaching from the used catalyst in commercial and economical aspects.

کلیدواژه ها:

Fischer-Tropsch ، Deactivation ، Cobalt catalyst ، Pre-oxidation ، Leaching ، Extractant ، Reflux