SEPARATION OF COBALT FROM EUROPIUM WITH MESOPOROUS HYBRID SlLlCA-POLY(STYRENE) IMPREGNATED CHELATING RESIN

摘要

This article describes resins for extraction chromatography capable of separating cobalt from europium. Radionuclides Eu-152 and Co-57 were used to represent the REEs and heavy metals. Resins were prepared by immobilizing poly(styrcne) on porous silica particles and impregnating the particles with an organic extractant: Octyl(pheuyl)-N,N-disiobutylcarbamoyhnethylphosphineoxide (CMPO), bis(2,4,4-1rimethylphentyl)dithio-phosphinic acid (Cyanex-301), 2-thenoyl trifluoroacetone (HTTA), tributylphosphate (TBP) or dibenzo-21-crown-7 (DB2IC7). The specific adsorption of Eu(IIl) and Co(II) was studied by measuring distribution coefficients and uptake percentages as a function of contact time, solution pH and metal ion concentration. The new resins, especially Cyanex 30IISiO_2-P, provide rapid kinetics and high adsorption selectivity for Co(II). The efficient and selective adsorption of Eu(III) on SiO_2-P impregnated with CMPO, a bifunctional organophosphorus compound and HTTA, a fl-diketone compound, is attributed to strong complex formation between the soft donor atom of each chelating ligand and trivalcnt ion.