Ralph C. Gatrone

UPTAKE OF METAL IONS BY A NEW CHELATING ION-EXCHANGE RESIN. PART 1: ACID DEPENDENCIES OF ACTINIDE IONS*

ABSTRACT The uptake of several actinide ions [U(VI), Pu(IV), Np(IV), Th(IV] and Am(DI)) from nitric and hydrochloric acid solutions, and of U(VI) from near-neutral solutions by the new chelating ion-exchange resin, DiphonixTM, has been investigated. Diphonix is a polyfunctional resin containing sulfonic and gem-diphosphonic acid groups chemically bonded in a styrene-divinylbenzene polymeric network. Comparison of the acid dependencies of the actinide ions uptake measured with Diphonix with those obtained using a commercial sulfonic -type resin and a resin containing both sulfonic and monophosphonic aCid groups, hat Shown that Diphonix binds the actinides via a different kind of chemical interaction, involving the.formation of chelate complexes through the phosphoryl groups of the gem-diphosphonic acids. As a consequence, Diphonix is superior to other resins in extracting actinide ions from very acidic solutions. A better performance of Diphonix is also observed with the uptake of uranium from neutral solu...

The Synthesis and Purification of the Carbamoylmethylphosphine Oxides

ABSTRACT The details of the synthesis and purification of symmetrical and unsymmetrlcal carbamoylmethylphosphine oxides (CMPO s) are described. The approaches used to provide a variety of substitution patterns around the two potential donor groups include the Arbusov, Michaelis-Becker and Grignard reactions. Several methods for purifying the extractants were studied. The use of acidic and basic ion exchange resins in conjunction was developed for the removal of acidic impurities which are very troublesome to the extraction performance of these compounds.

Hydrolytic and Radiolytic Degradation of Oφd(iB)Cmpo: Continuing Studies

Abstract The hydrolytic and radiolytic degradation of octyl(phenyl)-N, N-diisobutylcarbamoyl-methylphosphine oxide (CMPO) in tetrachloro-ethylene (TCE) and in tributylphosphate-TCE mixtures (TRUEX process solvent) in contact with HNO3 has been investigated. Gas chroma-tographic analysis of the degraded solutions has allowed identification and quantitation of a variety of organophosphorus degradation compounds derived from CMPO. The effect of degradation of the extractant solutions on the extraction and stripping of americium has been addressed, as has the effectiveness of Na2CO3 scrub procedures for restoring extractant performance. Extrapolation of these results to normal process application conditions indicates that neither hydrolysis nor radiolysis should compromise the americium extraction performance of TRUEX-TCE.

Behavior of americium in the strip stages of the TRUEX process

ABSTRACT The TRUEX (TRansUranium Extraction) process, recently developed at Argonne National Laboratory, separates and concentrates transuranium elements from acidic nuclear wastes. It is based on the use of the neutral extractant octyl(phenyl)–N,N–diisobutylcarbamoylmethylphosphine oxide (CMPO). CMPO Is combined with tributylphosphate (TBP) and a diluent to formulate the TRUEX process solvent. An attractive feature of the TRUEX process is that it allows the separation of americium from plutonium by using two different strip solutions. A detailed knowledge of the chemistry of americium in the stripping stages is essential for a successful Am/Pu separation. In this work the distribution ratio of Am(III) between TRUEX process solvent and diluted nitric acid has been measured in up to six successive strip experiments. The behavior of americlum during stripping has been correlated to the purity of the CMPO and the composition of the feed solution. With simulated waste solutions and with SX-grade CMPO, it is p...

Synthesis and characterization of a bifunctional ion exchange resin with polystyrene-immobilized diphosphonic acid ligands

A new ion exchange resin for the selective complexation of metal ions has been synthesized by functionalizing vinylbenzyl chloride-styrene-divinylbenzene copolymer beads with the sodium salt of tetra(isopropyl) methylene diphosphonate. The effects of bifunctionality, matrix rigidity, degree of functionalization, and macroporosity on final resin properties have been quantified. A sulfonic acid-diphosphonic acid bifunctional resin is highly selective with rapid complexation kinetics. A macroporous polymer matrix crosslinked with 10% divinylbenzene provides optimum results; for example, 99.7% Eu(III) is complexed from a 1M nitric acid solution with a 30-min contact time. The importance of physical crosslinking as well as chemical crosslinking in limiting access of substrates into polymer-supported reagents is discussed.

THE SYNTHESIS AND PROPERTIES OF SOME NEW CARBAMOYL( ALKYL) PHOSPHINE OXIDES

ABSTRACT Several substituted carbamoyl( alkyl) phosphine oxides have been synthesized and characterized with regard to their spectral properties and extraction capability for trivalent actinides from nitrate media. The effects that structural variation have upon the solubility, the extraction data, and the propensity to form third phases have been determined

Am(III) AND Eu(III) EXTRACTION BY ALIQUAT-336 AND BENZYL SUBSTITUTED QUATERNARY AMMONIUM SALTS FROM NITRATE AND THIOCYANATE SOLUTIONS*

ABSTRACT The extraction of Am(III) and Eu(III) from HN03 - L1NO3 or from HCOOH -NH4SCN solutions by different quaternary ammonium salts dissolved in o-xylene was investigated as function of the aqueous phase composition. As extractants, the nitrate or thiocyanate salts of Aliquat*336, tridodecylmethylammonium, benzyl-dimethyldodecylammonium, p-methoxybenzyldimethyldodecylammonium and p-trifluoromethylbenzyldimethyldodecylammonium were used. The extraction data obtained with the thiocyanate - formic acid aqueous solutions were quantitatively interpreted by a reaction scheme that takes into account the aqueous metal complexation and the competition of formic acid and metal species for the extractant reaction center. The effect of the benzyl group (whether substituted or not) on the metal and acid extraction by the different quaternary ammonium salts was interpreted on the basis of the inductive effect of the substituents. In the thiocyanate system, Aliquat*336 provided the highest Am/Eu separation factors.

THE SPECTRAL PROPERTIES OF THE CARBAMOYLMETHYLPHOSPHINE OXIDES

ABSTRACT The details of the NMR spectra (31P, 13C, 1H), for selected carbamoylmethylphosphine oxides are provided. A correlation between the 31P chemical shift and the nitric acid extraction constant (kHNO 3) has been determined for these compounds. The carbon and proton spectral data are usually very complex but a number of generalities in this data are noted which aid in the structural assignments. The mass spectral data is presented and some indication of the probable fragmentation pattern Is given.

The Synthesis and Decomposition of Novel Organophosphorus Complexants

Abstract Aqueous soluble organic diphosphonic acids have been synthesized as aids in the extraction/recovery of metal values from nuclear waste, ground water, or hydrometallurgical processes. The reagents form aqueous soluble complexes at very low pH values (< 1). After use, these compounds do not represent an additional waste management problem as they are readily decomposed to innocuous materials (phosphoric acid and carbon dioxide) by warming and/or by the action of a mild oxidizing agent.

THE EFFECT OF STERIC HINDRANCE OF THE AMIDIC SUBSTITUENTS OF THE CARBAMOYLMETHYLPHOSPHINE OXIDES ON THIRD PHASE FORMATION

Abstract Increasing the steric hindrance of the substituents on the amidic nitrogen of the carbamoylmethylphosphine oxide class of extractants leads to a significant decrease in the tendency of these compounds to form a third phase during the extraction of nitric acid. An increase in steric hindrance leads to a reduction in the accessibility of the nitrogen and in the dipole-dipole and dipole-induced-dipole attractions between extractant molecules, thereby reducing the tendency to form a third phase. A corresponding increase in the amount of uranium that could be extracted without third phase formation was not observed due to a reduction in the interaction of the extractant with the diluent because of coordination with the metal ion by both polar groups.