Cobalt Extraction from Sulfate/Chloride Media with Trioctyl(alkyl)phosphonium Chloride Ionic Liquids

Dairo E Chaverra; Oscar J Restrepo-Baena; María C Ruiz

doi:10.1021/acsomega.9b03266

Cobalt Extraction from Sulfate/Chloride Media with Trioctyl(alkyl)phosphonium Chloride Ionic Liquids

ACS Omega. 2020 Mar 13;5(11):5643-5650. doi: 10.1021/acsomega.9b03266. eCollection 2020 Mar 24.

Authors

Dairo E Chaverra^{1

2}, Oscar J Restrepo-Baena¹, María C Ruiz²

Affiliations

¹ Department of Materials and Minerals, School of Mines, Universidad Nacional de Colombia, Calle 59A No. 63-20 Bloque 54, Medellín 050034, Colombia.
² Department of Metallurgical Engineering, University of Concepcion, Edmundo Larenas 285, Concepción 3349001, Chile.

Abstract

The application of phosphonium-based ionic liquids (ILs) on the selective extraction of cobalt is presented. The extraction mechanism is established, and different parameters of the process are evaluated. It has been found that it is possible to extract cobalt from aqueous solutions in sulfate media, with the addition of sodium chloride, using phosphonium ILs. The cobalt extraction was selective with respect to nickel and strongly dependent on the chloride concentration in the aqueous solution. The cobalt extraction is given by an anion exchange mechanism through an endothermic process. Cobalt extractions greater than 98% were obtained using the proposed methods. Cobalt stripping from the loaded IL phase using water was proved. Therefore, an alternative extraction process to traditional organic solvents is proposed. This alternative has additional advantages such as easy handling, lower costs in reagents and equipment, and risk reduction.