Chemistry of Diglycolamides: Promising Extractants for Actinide Partitioning

An optical scanner includes a light source, an optical coupler, an optical line image unit, a deflector, and an optical scanning unit. The optical scanning unit includes scanning lenses that guide the beams to a surface to be scanned. A surface on the deflector side of the scanning lens closest to a deflection reflecting surface has a negative power in a vertical scanning direction, and is a special toric surface in which a radius of curvature in a vertical scanning changes from an optical axis of the lens surface toward a periphery of the horizontal scanning direction. An F number of the beams toward the surface to be scanned of the scanning lens in the vertical scanning direction is larger in a peripheral part than in a central part in an effective scanning width.

Optical scanner and image forming apparatus

N,N,N′,N′‐Tetraoctyl diglycolamide (TODGA) has been evaluated as an extractant for the partitioning of minor actinides from simulated high level nuclear waste solutions. Acid uptake studies suggested that TODGA is more basic (KH: 4.1) as compared to TRUEX and DIAMEX solvents viz. CMPO (KH: 2.0) and DMDBTDMA (KH: 0.32), respectively. TODGA molecules display a tendency toward aggregation in n‐dodecane at lower acidities. Effect of diluent on the distribution behavior of Am(III) was studied employing diluents of different dielectric constants. N,N‐dialkyl amides with different alkyl groups viz. dibutyl decanamide (DBDA), di(2‐ethylhexyl) acetamide (D2EHAA), di(2‐ethylhexyl) propionamide (D2EHPRA), di(2‐ethylhexyl) isobutyramide (D2EHIBA), dihexyl octanamide (DHOA) and dihexyl decanamide (DHDA) were evaluated as phase modifiers. Distribution behavior of various metal ions viz. Am(III), Pu(IV), U(VI), Eu(III), Fe(III), Sr(II) and Cs(I) was studied from pure nitric acid solution as well as from simulat...

N,N,N′,N′‐Tetraoctyl Diglycolamide (TODGA): A Promising Extractant for Actinide‐Partitioning from High‐Level Waste (HLW)

Two new extraction chromatographic resins containing the diglycolamide class of molecules have been prepared and characterized, and potential applications identified. The new resins consist of 40 weight percent N,N,N′N′ tetraoctyldiglycolamide (TODGA) and N,N,N′N′ tetrakis‐2‐ethylhexyldiglycolamide (TEHDGA) sorbed onto 50–100 µm particle size Amberchrom® CG‐71. The new resins have capacities for Eu of approximately 0.086 mmol/mL of bed and are quite stable to extractant leaching. The resins were characterized by measuring the batch uptake of actinides, lanthanides, and yttrium, alkaline earths and 13 selected transition and post‐transition elements from HNO3 and HCl. Based on the uptake data, a number of very efficient separations were achieved using 0.5–2 mL bed volume columns and room temperature operation.

Novel Extraction of Chromatographic Resins Based on Tetraalkyldiglycolamides: Characterization and Potential Applications

NdFeB permanent magnets have different life cycles, depending on the applications: from as short as 2–3 years in consumer electronics to 20–30 years in wind turbines. The size of the magnets ranges from less than 1 g in small consumer electronics to about 1 kg in electric vehicles (EVs) and hybrid and electric vehicles (HEVs), and can be as large as 1000–2000 kg in the generators of modern wind turbines. NdFeB permanent magnets contain about 31–32 wt% of rare-earth elements (REEs). Recycling of REEs contained in this type of magnets from the End-of-Life (EOL) products will play an important and complementary role in the total supply of REEs in the future. However, collection and recovery of the magnets from small consumer electronics imposes great social and technological challenges. This paper gives an overview of the sources of NdFeB permanent magnets related to their applications, followed by a summary of the various available technologies to recover the REEs from these magnets, including physical processing and separation, direct alloy production, and metallurgical extraction and recovery. At present, no commercial operation has been identified for recycling the EOL NdFeB permanent magnets and the recovery of the associated REE content. Most of the processing methods are still at various research and development stages. It is estimated that in the coming 10–15 years, the recycled REEs from EOL permanent magnets will play a significant role in the total REE supply in the magnet sector, provided that efficient technologies will be developed and implemented in practice.

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REE Recovery from End-of-Life NdFeB Permanent Magnet Scrap: A Critical Review

The novel extractants, six diglycolamides synthesized in our laboratory, were investigated for actinide extraction from nitric acid into n-dodecane. The dependence of the distribution coefficients of Eu(III) and Am(III) on the length of alkyl chain in the extractants was examined. Among the diglycolamides studied, N,N,N′,N′-tetraoctyl-3-oxapentanediamide (TOOPDA) and N,N,N′,N′-tetradecyl-3-oxapentanediamide (TDOPDA) showed a sufficient solubility in n-dodecane, due to their appropriate lipophilicity modified by increasing the length of the alkyl chain attached to amidic N atoms. The distribution coefficients, D M, of actinides obtained by TOOPDA increased with an increase in HNO3 concentration. The number of diglycolamide molecules coordinated to the actinide ions was estimated to be three for Th(IV), U(VI), Pu(IV), and four for Am(III) and Cm(III) by slope analysis. The order of D M for the actinides at high nitric acid concentrations is An(III), An(IV) > An(VI) > An(V) and that for lanthanides, heavier ...

THE NOVEL EXTRACTANTS, DIGLYCOLAMIDES, FOR THE EXTRACTION OF LANTHANIDES AND ACTINIDES IN HNO3–n-DODECANE SYSTEM

N,N,N  ′,N  ′-Tetraoctyl-3-oxapentanediamide (TODGA) in n-dodecane solvent was studied to clarify the characteristics of third phase formation in extraction of lanthanides(III) and to modify the solvent. The loading capacity of the solvent was found to be dependent not only on the aqueous acidity and the temperature but also on molecular size of alkane solvent and kinds of aqueous anions. The loading capacity of 0.1 M TODGA-n-dodecane was 0.008 M Nd(III) with an aqueous phase of 3 M HNO3. Addition of N,N,-dihexyloctanamide (DHOA) of more than 0.5 M to the solvent eliminated the third phase in the extraction of Nd(III). The modified solvent of 0.1 M or 0.2 M TODGA with 1 M DHOA exhibited a satisfactorily high metal loading and slightly lower extractability for Nd(III) and moderately higher extraction of HNO3 than neat TODGA.

MODIFICATION OF TODGA- n -DODECANE SOLVENT WITH A MONOAMIDE FOR HIGH LOADING OF LANTHANIDES(III) AND ACTINIDES(III)

A method for the determination of extraction capacity and its application to N,N,N′,N′-tetraalkylderivatives of diglycolamide-monoamide/n-dodecane media

N,N,N′,N′‐Tetraoctyl‐3‐oxapentane diamide (TODGA) and its homologues were shown to be usefully applied to the extraction of divalent alkaline earth metal: M(II) ions from aqueous solutions of high nitric acid concentration, specifically around 3 M. The stoichiometry of the extracted Sr(II)‐DGA species was found to depend mainly on the concentration of nitric acid and molecular structure of DGA. The degree of extraction of M(II) by TODGA decreases in the order of Ca(II) > Sr(II) > Ba(II).

Solvent Extraction of Alkaline Earth Metal Ions by Diglycolic Amides from Nitric Acid Solutions

The present invention provides a near-infrared reflective film and a near-infrared reflector, which can be used over large areas and are flexible, and have low haze and high visible light transmittance. The near-infrared reflective film comprises at least one unit composed of a high refractive index layer and low refractive index layer on a substrate, and is characterized in that the refractive index difference between an adjacent high refractive index layer and low refractive index layer is at least 0.1, and said high refractive index layer contains at least one type of compound (A) selected from: 1) a rutile-type titanium oxide having a volume-average particle diameter of not more than 100 nm; 2) a water-soluble polymer; and 3) the following group of compounds. Group of compounds: a carboxyl group-containing compound, hydroxamic acids, pyridine derivatives.

Shinichi Suzuki

Papers

THE NOVEL EXTRACTANTS, DIGLYCOLAMIDES, FOR THE EXTRACTION OF LANTHANIDES AND ACTINIDES IN HNO3–n-DODECANE SYSTEM

MODIFICATION OF TODGA- n -DODECANE SOLVENT WITH A MONOAMIDE FOR HIGH LOADING OF LANTHANIDES(III) AND ACTINIDES(III)

A method for the determination of extraction capacity and its application to N,N,N′,N′-tetraalkylderivatives of diglycolamide-monoamide/n-dodecane media

Solvent Extraction of Alkaline Earth Metal Ions by Diglycolic Amides from Nitric Acid Solutions

Near-infrared reflective film, method for manufacturing near-infrared reflective film, and near-infrared reflector