Noble Metals and Spinel Settling in High Level Waste Glass Melters

Sundaram, S. K.; Perez, J.M.

doi:10.2172/786806

Cited by 11 publications

(10 citation statements)

References 15 publications

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“…IR spectra were recorded as nujol mulls using a JASCO-610 FITR spectrometer. 1 H NMR spectra were recorded using a Bruker AMX-300 spectrometer or Varian 500 MHz instruments. The chemical shifts (δ) are reported in ppm and coupling constants ( J) are reported in hertz.…”

Section: Methodsmentioning

confidence: 99%

“…Yield (80%). 1 (7) To a solution of Pd(NO 3 ) 2 •2H 2 O (1 mmol) in acetonitrile, ligand L1 (2 mmol) was added and stirred for 5 hours. This solution was evaporated to dryness and the resulting residue was washed with hexane and dried.…”

Section: General Synthesis For Complexes Of Palladium Chloridementioning

confidence: 99%

“…The separation of platinum group metals (PGM) from spent catalysts obtained from automotive petroleum industries and high level liquid waste (HLW) from nuclear processes has been a topic of recent interest and offers an opportunity for hydrometallurgist and separation scientists, arising from the value of the metals and their application in various fields. [1][2][3][4] Various new extractants containing soft sulphur and nitrogen atoms have been explored for this purpose in recent years. 5 Among them, extractants based on dithiodiglycolamide (Fig.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis, structural and theoretical studies of dithiodiglycolamide compounds of palladium(ii)

et al. 2015

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The reaction of palladium(ii) halide with dithiodiglycolamide ligands yielded compounds of the type [PdX2L] (where X = Cl, L = (CH2SCH2CON(i)Pr2)2 (1); L = (CH2SCH2CON(i)Bu2)2 (2); L = (CH2SCH2CONBu2)2 (3); L = C7H6(SCH2CON(i)Bu2)2 (4); X = Br, L = (CH2SCH2CON(i)Bu2)2 (5); X = I, L = (CH2SCH2CON(i)Bu2)2 (6)), whereas palladium(ii) nitrate yielded compounds of the type [PdL2](NO3)2 (where L = (CH2SCH2CON(i)Pr2)2 (7); L = (CH2SCH2CON(i)Bu2)2 (8)). All compounds were characterized by using IR, (1)H NMR spectral techniques and CHN analyses. The structures of compounds 4, 5 and 7 have been determined by using X-ray diffraction methods. The structures show that the ligands bond through the thioether group to the metal centre in all compounds. They show further that the palladium(ii) ion is surrounded by four atoms (two halogens and two thio groups in 4 and 5 and four thio groups in 7) in a square planar arrangement. The dithiodiglycolamide ligand acts as a bidentate chelating ligand and bonds through both the thioether groups to the metal centre, leaving the carbamoyl groups uncoordinated. Theoretical studies reveal that the 1 : 2 compound is energetically more stable and nicely correlates with the IR carbamoyl stretching frequencies as compared to the 1 : 1 compound in which the ligand acts as a tetradentate ligand.

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Section: Methodsmentioning

confidence: 99%

Section: General Synthesis For Complexes Of Palladium Chloridementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Synthesis, structural and theoretical studies of dithiodiglycolamide compounds of palladium(ii)

et al. 2015

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“…Three major melter test campaigns testing noble metals have been completed in the past: 1) PNNL test, 2) German melter test, and 3) Integrated DWPF (Defense Waste Processing Facility) Melter System (IDMS). Noble metals have been included in glass development studies since some of the earliest waste solidification and vitrification work at PNNL (Sundaram and Perez, 2000). The insolubility of noble metals in glasses was observed at those early stages and was also known from the literature; however, the effect this insolubility could have on melter operation was not known.…”

Section: Summary Of Past Melter Datamentioning

confidence: 99%

Evaluation and Testing of Noble Metals Surrogates

Sundaram¹,

D.²,

Cooper³

et al. 2002

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This report summarizes the results of testing and evaluation of noble metal surrogates that will support testing of noble metals in melters. The candidate system, potential surrogates, model glass systems, and test conditions have been chosen based on the existing reported data in literature as well as expertise existing at various sites, thermodynamics, physical properties, and cost of materials. The methodology involves testing interaction of RuO 2 and WO 3 and other surrogates in the test melt followed by characterization of the bulk glass and oxide-glass melt interfaces. The report explains different techniques used for studying settling, crystallization, rheology, and partitioning of noble metals or surrogates or spinel phases in the selected systems. The report presents and discusses how these results support the selection of the suitable surrogate for RuO 2. Finally the report concludes with identification of the best-suited surrogate (solubility and redox surrogate WO 3 and conductivity surrogate Cr 2 O 3) proposed and makes suitable recommendations for the follow up melter test activities.

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“…Other phases commonly reported include molybdates and the so-called yellow phase. 5,[9][10][11] The presence of these secondary phases may have significant and deleterious effects on material performance as a wasteform. For example, yellow phase is more soluble in water than the glass matrix, providing an efficient route for radionuclides to escape the wasteform.…”

Section: Introductionmentioning

confidence: 99%

Atomic-scale description of interfaces in rutile/sodium silicate glass–crystal composites

Fossati

Rushton

Lee

2018

Phys. Chem. Chem. Phys.

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In this work interfaces between (Na2O)x(SiO2)1-x glasses (for x = 0.0, 0.1 and 0.2) and TiO2 crystals are simulated using molecular dynamics and empirical potentials. Interfaces are presented for the distinct terminating surfaces of TiO2 with Miller indices ≤2, the properties of which have been investigated using atomistic models. Simulations showed that partially ordered layers had been induced in the glass close to the interfaces, with successive oxygen-rich and cation-rich planes being noted. The first silicate layer in contact with the crystal tended to be highly-structured, with Si ions occupying well-defined positions that depend on the orientation of the crystal at the interface, and showing 2-dimensional ordering depending on glass composition. Finally, interface energies were calculated. These indicated that the interface formation may stabilise a crystal surface in comparison to maintaining a free surface. Results are presented suggesting that the structural flexibility of the glass network allows it to conform to the crystal, thereby providing charge compensation and avoiding large relaxation of the crystal structure close to the interfaces. Such interfacial properties could be crucial to improving phenomenological models of glass-crystal composite properties.

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Noble Metals and Spinel Settling in High Level Waste Glass Melters

Cited by 11 publications

References 15 publications

Synthesis, structural and theoretical studies of dithiodiglycolamide compounds of palladium(ii)

Synthesis, structural and theoretical studies of dithiodiglycolamide compounds of palladium(ii)

Evaluation and Testing of Noble Metals Surrogates

Atomic-scale description of interfaces in rutile/sodium silicate glass–crystal composites

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