Solvent extraction separation of Mo and Co from chloride solution containing Al

Abstract

Solvent extraction studies were carried out to investigate the selectivity of some extractants towards Mo and Co from synthetic acidic chloride leach solution of spent HDS catalyst. The composition of the synthetic solution was (in ppm): Mo-394, Co-119, Al-1782 and 3 kmol/m3 of HCl. Among the several solvating and amine extractants that were tested, TOPO and Alamine 308 showed some potential towards the extraction of Mo and Co, respectively. The reasons for this greater extraction tendency of the corresponding extractants were also described thoroughly. Furthermore, the separation of Co and Al was investigated by varying the concentration of HCl. Finally, a possible extraction system for the separation of Mo and Co was presented. Our results can be utilized in developing a process for the recovery of Mo and Co from spent catalysts. © 2012 The Japan Institute of Metals.