Selective Separation and Preconcentration of Thorium(IV) in Bastnaesite Ore Using Thorium(IV)-Imprinted Cryogel Polymer

Abstract

I n this study, selective separation and preconcentration of Th(IV) in aqueous solutions and bastnaesite ore in the presence various lanthanide ions by using Th(IV)-imprinted polymer was conducted. For this purpose, Th(IV) was complexed with N-methacryloyl antipyrine (MAAP) and the prepared (MAAP)2-Th(IV) complex monomer was polymerized with 2-hydroxyethyl methacrylate (HEMA) cryogel to prepare pHEMA-(MAAP)2- Th(IV) cryogel polymer by free radical polymerization. Th(IV) was desorbed with 5.0 mol.L-1 HNO3 and thus Th(IV)-imrinted were created onto p-HEMA-(MAAP)2 cryogel polymer. To determine the optimum conditions, in the process of selective binding of Th(IV) ion to Th(IV)-imprinted p-HEMA-(MAAP)2 cryogel polymer, some parameters such as pH, flow rate, initial Th(IV) concentration were investigated. Under the optimum conditions, the maximum binding capacity was obtained as 48.30 mg.g-1. Selectivity studies were also carried out in the presence of Ce(III), La(III) and Eu(III) ions using Th(IV)-imprinted p-HEMA-(MAAP)2 cryogel polymer. It was found that p-HEMA-(MAAP)2 cryogel polymer displayed high selectivity toward Th(IV) ion.