Removal of Metal Impurities from the Spent Hydroprocessing Catalyst and Acid Leaching Kinetics of Aluminum

摘要

The impurity metal of Al in spent hydroprocessing catalyst (Mo-Ni/Al_2O_3) was removed by HCl, and the metals of Mo and Ni were preliminarily enriched. The results show that the leaching efficiency of Al was 88.62%, and the leaching efficiency of Mo and Ni were 16.32% and 28.74%, respectively. The results were achieved under optimal leaching conditions: the particle size was 150 μm, the concentration of HCl was 4 mol/L, the leaching temperature was 90 °C, and the leaching time was 120 min. The kinetics of the leaching behavior of Al showed that the acid leaching reaction of Al was in accorded with the equation 1-2/3X-(1-X)~(2/3)=K2t, R~2=0.97734, which was controlled by internal diffusion. X-ray diffraction analysis of the leaching residue revealed the existence of residual metals Mo(MoO_3, MoO_2(ClO_4)_2)and Ni(NiS). The separation of Al from Mo and Ni has been preliminarily realized, which is conducive to further efficient recovery of Mo and Ni.