Akademik Veri Yönetim Sistemi
JOURNAL OF SUSTAINABLE METALLURGY, cilt.12, sa.1, ss.169-183, 2026 (SCI-Expanded, Scopus)
Spent Ni-Mo hydrodesulfurization (HDS) catalysts represent a valuable secondary resource of critical metals, yet their conventional hydrometallurgical recycling routes often involve environmentally hazardous reagents. In this study, a deep eutectic solvent (DES) based on choline chloride and p-toluenesulfonic acid (ChCl:PTSA) was investigated as a green leaching medium for the recovery of Ni, Mo, Al, and P from end-of-life Ni-Mo HDS catalysts. The effects of key operational parameters-grinding, stirring speed, temperature, HBA/HBD ratio, leaching time, and solid/liquid ratio-were systematically examined. Leaching kinetics were investigated using experimental data, and kinetic models, including shrinking core model (SCM) chemical reaction, film diffusion, and product layer diffusion control, were compared. The results highlight the dominant kinetic mechanisms governing metal dissolution in this DES system. Complementary characterization of the spent catalysts and leach residues was performed using SEM-EDS and related techniques to elucidate morphological and compositional changes. This work demonstrates the potential of ChCl:PTSA-based DES as a sustainable alternative to conventional leaching agents, offering an environmentally benign pathway for the valorization of spent Ni-Mo HDS catalysts.