THE OXIDATION OF URANIUM AND SOME URANIUM COMPOUNDS IN LIQUID AMMONIA

Thesis/Dissertation · Sun Jan 01 00:00:00 EST 1961

OSTI ID:4783922

Kershner, C J

A study is made to determine conditions and find effective oxidizing agents for accomplishing the oxidation of uranium in liquid ammonia. After establishing suitable systems, the valence state of uranium in the oxidized uranium compound and the composition of this compound are determined. In view of the possibility of the formation of an ammonia system analog to the dioxouranium(VI) ion, an effort is made to identify any uranium(VI) species formed. Precautions are employed to exclude water vapor and air from the reaction systems. All reagents are prepared or purified by methods designed to render them as anhydrous as possible. Hygroscopic or air-sensitive materials are handled and weighed in a dry box under a nitrogen atmosphere. A vacuum line is employed for the manipulation and addition to the reaction vessel of the ammonia solvent and the reactants. Most of the reactions are carried out at room temperature in sealed heavy-walled Pyrex vessels. These reaction vessels are separated into two chambers by a sintered glass disk, which furnishes a means of separating the insoluble and soluble reaction products while the vessel is sealed and free from atmospheric contamination. Microcrystalline uranium metal, UH/sub 3/, UO/sub 2/, and U(OAc)/sub 4/ are used as reducing agents and AgNO/sub 3/, AgI, AgOAc, HgI/sub 2/, Hg(CN)/sub 2/, CuCl/sub 2/, and CuI are used as oxidizing agents. The reaction products are investigated by chemical, x-ray, and infrared methods. After the products are identified, quantitative studies are made to determine the stoichiometry of the reactions. The only systems that react with high enough rates to be useful for stoichiometric studies are those containing acetate. Both uranium metal and uranium (IV) acetate react with silver acetate to produce silver metal, acetamide, and uranium(VI). In the reaction with uranium metal, evidence is found that indicates that the various oxides of uranium are formed in the course the reaction. Initially, in both reactions involving uranium the metal and uranium(IV) acetate as reducing agents, the oxidized uranium is present as a soluble acetate-complexe species of the dioxouranium(VI) ion, but the acetates associated with the uranium(VI) slowly solvolyze to produce acetamide and the uranium precipitates as solvated ammonium diuranate. The uranium(VI) species in the system containing acetate is formulated as (NH/sub 4/)UO/sub 2/(OAc)/sub 4/, and two possible mechanisms for the redox reaction between silver acetate and uranium(IV) acetate are given on the basis of the chemical, x-ray and infrared evidence acquired. In the first mechanism, an activated complex are bridged by an acetate group. Nucleophilic attack by ammonia on the carbonyl carbon of the bridged acetate is proposed as the mechanism for the production of acetamide and of dioxouranium(VI) ion. The second mechanism proposes an intermediate uranium(V) species, U(OAc)/sub 5/, which disproportionates and undergoes solvolysis to produce uranium(IV) acetate, acetate-complexed dioxouranium(VI) species, and acetamide. There is no evidence for the formation of an ammonia solvent system analog to the dioxouranium(VI) ion. (Dissertation Abstr., 22: No. 7,

• Research Organization: Originating Research Org. not identified
• NSA Number: NSA-17-000175
• OSTI ID: 4783922
• Resource Relation: Other Information: Thesis. Orig. Receipt Date: 31-DEC-63
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHEMISTRY
ACETATES
AMMONIA
AMMONIUM COMPOUNDS
COPPER CHLORIDES
COPPER IODIDES
CYANIDES
GLASS
HUMIDITY
IMPURITIES
INERT GASES
INFRARED RADIATION
LIQUIDS
MERCURY COMPOUNDS
MERCURY IODIDES
NITROGEN
OXIDATION
PRECIPITATION
QUALITATIVE ANALYSIS
REACTION KINETICS
SEALS
SILVER COMPOUNDS
SILVER IODIDES
SILVER NITRATES
URANATES
URANIUM
URANIUM COMPLEXES
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM HYDRIDES
VACUUM
VESSELS
X RADIATION