The effectiveness of ion exchange resins in separating uranium and thorium from rare earth elements in acidic aqueous sulfate media. Part 1. Anionic and cationic resins

Abstract

Conventional ion exchange resins with different functional groups were evaluated for their potential application in separating uranium U(VI) and thorium Th(IV) from rare earth elements RE(III). The resins studied comprised strong-and weak-base anion exchange resins, and strong-and weak-acid cation exchange resins. The selectivity of these resins to adsorb U(VI) and Th(IV) in the presence of selected RE(III) was examined in sulfuric acid media of varying concentrations. It was evident that the adsorption performance of the resins was acid concentration-dependent. Most candidate resins had potentially feasible selective adsorption at or below 0.1 mol/L H 2 SO 4 (pH ≥ 0.7). Within the group of anion exchange resins, both the strong-and weak-base resins exhibited a similar selectivity with U(VI) adsorbed in preference to RE(III). The difference between them was their adsorption of Th(IV). The weak-base resin with primary amine functional group demonstrated superior separation of Th(IV) from RE(III). For this resin, 78% of U(VI) and 68% of Th(IV) were adsorbed while RE(III) co-adsorption was less than 5% at 0.0005 mol/L H 2 SO 4 (pH 3). In the case of the strong-acid cation exchange resins, Th(IV) and RE(III) were adsorbed in preference to U(VI), i.e., RE(III) > Th(IV) >> U(VI). The weak-acid cation exchange resins, on the other hand, displayed limited adsorption of all elements.

The Functionality of Ion Exchange Resins for Esterification, Transesterification and Hydrogenation Reactions

“…[19,42] The use of ion exchange resins for these chemical industrialized processes have also been widely reported. [43][44][45][46] A typical example is the esterification reaction of methanol and acetic acid reaction yielding methyl acetate. [47] Majorly, the reaction represented in Eq.…”

“…In order to enhance the reusability, selectivity, activity, ester contamination, effluent problems and cost management, the application of solid acidic catalysts is very effective . The use of ion exchange resins for these chemical industrialized processes have also been widely reported . A typical example is the esterification reaction of methanol and acetic acid reaction yielding methyl acetate .…”

Synergistic solvent extraction of neodymium form nitric acid medium using Cyanex 302 and D2EHPA

“…[3][4][5] In this regard, finding efficient mechanisms and techniques for their extraction from aqueous solutions has attracted great attention in these days. There are several methods for the recovery/removal of rare earths from different aqueous solutions, including ion exchange, [6] precipitation, [7,8] adsorption, [9,10] membrane separation, [11] and solvent extraction. [12,13] Due to the requirement for high purity neodymium, solvent extraction method is progressively applied to replace precipitation in unit operations of metallurgy due to sludge production.…”

Disposal of Uranium and Thorium Entering the Human Digestive System before Reaching the Blood by Adsorption on Simethicone and Forming a Non-absorbable Compound: A Full in vitro Analysis

“…9 Uranium dust content varies according to the type of the source, [10][11][12] it was determined by complex formation using piroxicam, 13 meloxicam, 14 2-(2-thiazolylazo)-p-cresol (tac), 15 arsenazo iii, 16 2-ethanolimino-2pentylidino-4-one, 17 a mixture of -xylene and benzene, 18 azide ions, 19 acetylacetonate. 20 Many procedures have been developed for determination of thorium including liquid-liquid extraction, 21,22 ion-exchange resins, 23,24 liquid membrane 25 and solid phase extraction (SPE). [26][27][28][29] According to U.S. Food and Drug Administration approval of simethicone, we were select it due to the safety on the human body and not need more tests on humans.…”