Neptunium suspensions

Neptunium V sorption on hematite (a-Fe20 ) in aqueous suspension the effect of CO2. Radiochim. Acta 85 3348 Kolb, E.D. Caporaso, A.J. Laudise, R.A. 

Solid Phase Analyses. Portions of the Np solids from several suspensions were removed after 200 days, rinsed and dissolved in HC1. The Np oxidation state analyses of the dissolved solids (Table II) indicate that while the solids from various low pH suspensions contain predominantly Np(IV), high pH suspensions contain Np solids of mixed-Np oxidation states. Even though the TTA values are lower, the sum of the extracted and non-extracted neptunium (relative to the total Np solution concentration) does not account for all the Np. This may indicate that the Np(IV) values could be higher. Recoveries in predominantly Np(V) solutions were nearly 100%. 

Strickert, R. G. Rai, Dhanpat, "Solubility-Limited Neptunium Concentrations in Redox-Controlled Suspensions of Np02M> U.S. Department of Energy Report PNL-SA-10590,... 

Die Reindarstellung gelingt durch fraktionierte Vakuumsublimation. Tetrakis(cyclopentadienyl)neptunium(IV) (C5H5)4Np, der erste reine Aromatenkomplex des Neptuniums, wurde durch Umsetzung von NpCl4 mit einer benzolischen Suspension von KC5H5 als rotbraunes Produkt dargestellt 243> ... 

Much less work has been reported for the 6-valent elements as compared with the volume of literature for the actinides in lower valence states. Hydrated neptunium and plutonium trioxides are now known, Np03 H2O and PUO3 (0.8)H2O being readily obtained by the action of ozone on an aqueous suspension of neptunium (V) or plutonium (IV) hydroxides at 90°C. (23) Np03 2H2O is obtained in a similar manner at 18°C. (23) or by ozone oxidation of neptunium (V) in a molten lithium-potassium nitrate eutectic at 150°C. (42). 

Mhere materials are labelled with an asterisk, a large number of powders were successfully deposited using the suspension medium described. Mizuguchi et al included alumina barium, strontium and calcium carbonates magnesia, zinc oxide, titanium dioxide, silica, indium oxide, lanthanum boride, tungsten carbide, cadmium sulfide and several metals and phosphors. The list of materials described by Gutierrez et al included several metals carbides of molybdenum, zirconium, tungsten, thorium, uranium, neptunium and plutonium zirconium hydride, tantalum oxide and uranium dioxide. In addition, many metallic and oxide powder suspensions in alcohols, acetone and dinitromethane were studied by Brown and Salt ... 

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