Industrial & Engineering Chemistry Research · 2010 · 18 citations · 20 references
Natural SciencesChemical EngineeringChemistryCatalysisSurface ChemistrySurface ScienceAcid-base ChemistryCatalytic Reaction KineticsSurface CatalysisSurface KineticsSurface Reaction KineticsSurface ReactionsCatalytic Surface KineticsChemical Surface ModificationCobalt CatalysisCobalt Oxide CatalystsDissolution ReactionsMetal DissolutionMineral Dissolution KineticsMineral Dissolution Mechanisms
In this study, the dissolution of CoO from CoO/Al 2 O 3 catalyst with HCl, H 2 SO 4, and HNO 3 solutions was investigated in a batch reactor employing parameters that were expected to affect the dissolution rate of cobalt, such as stirring speed, temperature, and acid concentration. It was found that 99.82% of cobalt was dissolved after 4 h with HCl at 2 M, 75 °C, and a liquid-to-solid ratio (l/s) of 100 mL/g, while only 31.96% and 13.57% cobalt dissolutions were reached with H 2 SO 4 and HNO 3, respectively, under the same operation conditions. The difference in dissolution rates was due to the presence of different anions (Cl −, NO 3 −, and HSO 4 − ) involved in the surface reactions. Dissolution kinetic of cobalt was examined according to a heterogeneous model. It was found that the dissolution rate was controlled by surface chemical processes in all cases.
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Leaching of copper oxide with different acid solutions
N. Habbache, N. Alane, Souad Djerad et al. · Chemical Engineering Journal · 2009 · 287 citations