Cobalt and nickel uptake by silica-based extractants. Issue 10 (3rd July 2018)

• Record Type: Journal Article
• Authors: Pepper, Sarah E.; Whittle, Karl R.; Harwood, Laurence M.; Cowell, Joseph; Lee, Taek Seung; Ogden, Mark D.
• Is Part Of: Separation science and technology. Volume 53:Issue 10(2018)
• Page Start: 1552
• Page End: 1562
• Publication Date: 2018-07-03
• Subjects: Ion exchange -- silica-based resin -- Purolite S950 -- cobalt -- nickel; Separation (Technology) -- Periodicals; 660.284205
• DOI: 10.1080/01496395.2017.1405034
• Languages: English
• ISSNs: 0149-6395

Abstract

ABSTRACT: The pKa s of ethyl/butyl phosphonate silica (EBP-Si) have been determined, and the removal of cobalt and nickel from solution was investigated as a function of various parameters and compared with those of Purolite S950. pH uptake experiments suggested a combination of ion exchange and acid dissociation of the surface occurring. Isotherm data, fitted using the Langmuir and Dubinin–Radushkevich (D-R) models, indicated that stronger complexes formed with S950 than with EBP-Si. Kinetic data, fitted using a pseudo-second-order model, suggested that the rate-determining process is the reaction of metal ions with the chelating functionality of the resin. Uptake by EBP-Si is two to three times faster than that on S950.