Recovery of nickel, cobalt, and aluminum from molybdenum extraction residue of spent hydrodesulfurization catalyst

Abstract

ABSTRACT Spent hydrodesulfurization (HDS) catalyst is an important secondary resource for extracting molybdenum. After the extraction of Mo from the spent HDS catalyst, a molybdenum extraction residue containing aluminum, nickel, and cobalt was obtained. In the work presented herein, the extraction of nickel, cobalt, and aluminum from the molybdenum extraction residue by hydrochloric acid leaching was investigated. The effects of hydrochloric acid leaching on the extraction of nickel, cobalt, and aluminum as well as the kinetics of nickel and aluminum leaching were studied in detail. The leaching of nickel, cobalt, and aluminum reached up to 98.4%, 99.6%, and 83.5% respectively, under the optimal conditions including the molybdenum extraction residue leached at 95°C for 4 h with 5 mol/L HCl, as well as a liquid/solid ratio of 10 mL/g. The kinetics analysis showed that both nickel and aluminum leaching was controlled by chemical reactions, and the leaching apparent activation energies were 90.52 KJ/mol and 73.63 KJ/mol, respectively.