Uranyl oxalate

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Uranyl oxalate
U Oxalate Trihydrate.tif
Names
Other names
Uranyl oxalate trihydrate; uranyl oxalate hydrate
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
  • InChI=1S/C2H2O4.2O.U/c3-1(4)2(5)6;;;/h(H,3,4)(H,5,6);;;/q;;;+2/p-2
    Key: PRWGGWFEEGTKSV-UHFFFAOYSA-L
  • C(=O)(C(=O)[O-])[O-].O=[U+2]=O
Properties
UO2C2O4
Molar mass 358 g/mole (412 g/mol as trihydrate)
AppearancePale yellow powder
Partially soluble
Related compounds
Related uranium oxides
Uranyl peroxide
Triuranium octoxide
Uranium dioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Uranyl oxalate (UO2C2O4) is a pale yellow powdered uranyl salt. It is often encountered in industrial nuclear processes at both the front and back-end of the nuclear fuel cycle. Due to its hygroscopicity, uranyl oxalate rarely exists in the dehydrated state and is usually instead found in the trihydrate form (UO2C2O4·3H2O) at room temperature. [1] At room temperature, the powder exhibits a monoclinic crystal structure in the P21/c space group. [2]

Production

Uranyl oxalate trihydrate can be produced by the reaction of uranyl nitrate hexahydrate with oxalic acid. [3]

Uranyl oxalate has been used in actinometers. [4]

Related Research Articles

<span class="mw-page-title-main">Oxalate</span> Any derivative of oxalic acid; chemical compound containing oxalate moiety

Oxalate is an anion with the chemical formula C2O2−4. This dianion is colorless. It occurs naturally, including in some foods. It forms a variety of salts, for example sodium oxalate, and several esters such as dimethyl oxalate. It is a conjugate base of oxalic acid. At neutral pH in aqueous solution, oxalic acid converts completely to oxalate.

A solubility chart is a chart describing whether the ionic compounds formed from different combinations of cations and anions dissolve in or precipitate from solution.

<span class="mw-page-title-main">Uranium trioxide</span> Chemical compound

Uranium trioxide (UO3), also called uranyl oxide, uranium(VI) oxide, and uranic oxide, is the hexavalent oxide of uranium. The solid may be obtained by heating uranyl nitrate to 400 °C. Its most commonly encountered polymorph is amorphous UO3.

<span class="mw-page-title-main">Uranyl peroxide</span> Chemical compound

Uranyl peroxide or uranium peroxide hydrate (UO4·nH2O) is a pale-yellow, soluble peroxide of uranium. It is found to be present at one stage of the enriched uranium fuel cycle and in yellowcake prepared via the in situ leaching and resin ion exchange system. This compound, also expressed as UO3·(H2O2)·(H2O), is very similar to uranium trioxide hydrate UO3·nH2O. The dissolution behaviour of both compounds are very sensitive to the hydration state (n can vary between 0 and 4). One main characteristic of uranium peroxide is that it consists of small needles with an average AMAD of about 1.1 μm.

<span class="mw-page-title-main">Uranyl chloride</span> Chemical compound

Uranyl chloride refers to inorganic compounds with the formula UO2Cl2(H2O)n where n = 0, 1, or 3. These are yellow-colored salts.

<span class="mw-page-title-main">Ammonium uranyl carbonate</span> Chemical compound

Ammonium uranyl carbonate (UO2CO3·2(NH4)2CO3) is known in the uranium processing industry as AUC and is also called uranyl ammonium carbonate. This compound is important as a component in the conversion process of uranium hexafluoride (UF6) to uranium dioxide (UO2). The ammonium uranyl carbonate is combined with steam and hydrogen at 500–600 °C to yield UO2. In another process aqueous uranyl nitrate, known as uranyl nitrate liquor (UNL) is treated with ammonium bicarbonate to form ammonium uranyl carbonate as a solid precipitate. This is separated from the solution, dried with methanol and then calcinated with hydrogen directly to UO2 to obtain a sinterable grade powder. The ex-AUC uranium dioxide powder is free-flowing, relatively coarse (10 μ) and porous with specific surface area in the range of 5 m2/g and suitable for direct pelletisation, avoiding the granulation step. Conversion to UO2 is often performed as the first stage of nuclear fuel fabrication.

<span class="mw-page-title-main">Uranium nitrides</span> Chemical compound

Uranium nitrides is any of a family of several ceramic materials: uranium mononitride (UN), uranium sesquinitride (U2N3) and uranium dinitride (UN2). The word nitride refers to the −3 oxidation state of the nitrogen bound to the uranium.

<span class="mw-page-title-main">Potassium ferrioxalate</span> Chemical compound

Potassium ferrioxalate, also called potassium trisoxalatoferrate or potassium tris(oxalato)ferrate(III) is a chemical compound with the formula K3[Fe(C2O4)3]. It often occurs as the trihydrate K3[Fe(C2O4)3]·3H2O. Both are crystalline compounds, lime green in colour.

<span class="mw-page-title-main">Dysprosium titanate</span> Chemical compound

Dysprosium titanate (Dy2Ti2O7 or Dy2TiO5) is an inorganic compound, specifically a ceramic of the titanate family. Two common phases of this compound exist with differing properties: Dy2Ti2O7 and Dy2TiO5. Dysprosium titanate is commonly used throughout the nuclear industry in nuclear control rods and as a host for nuclear waste.

<span class="mw-page-title-main">Lead(II) oxalate</span> Chemical compound

Lead(II) oxalate is an organic compound with the formula PbC2O4. It is naturally found as a heavy white solid.

<span class="mw-page-title-main">Caesium oxalate</span> Chemical compound

Caesium oxalate, or dicesium oxalate, or cesium oxalate is a chemical compound with the chemical formula Cs2C2O4. It is a caesium salt of oxalic acid. It consists of caesium cations Cs+ and oxalate anions C2O2−4.

<span class="mw-page-title-main">Amorphous uranium(VI) oxide</span> Chemical compound

Amorphous uranium(VI) oxide(am-U2O7) is an orange diuranyl compound, most commonly obtained from the thermal decomposition of uranyl peroxide tetrahydrate at temperatures between 150 and 500 °C (300 and 930 °F). It exists at room temperature as a powder. Am-U2O7 does not comprise a regular, long-range atomic structure, as demonstrated by its characteristic diffuse scattering pattern obtained by X-ray diffraction. As a result, the molecular structure of this material is little understood, although experimental and computational attempts to elucidate a local atomic environment have yielded some success.

The borate oxalates are chemical compounds containing borate and oxalate anions. Where the oxalate group is bound to the borate via oxygen, a more condensed anion is formed that balances less cations. These can be termed boro-oxalates, bis(oxalato)borates, or oxalatoborates or oxalate borates. The oxalatoborates are heterocyclic compounds with a ring containing -O-B-O-. Bis(oxalato)borates are spiro compounds with rings joined at the boron atom.

<span class="mw-page-title-main">Yttrium oxalate</span> Chemical compound

Yttrium oxalate is an inorganic compound, a salt of yttrium and oxalic acid with the chemical formula Y2(C2O4)3. The compound does not dissolve in water and forms crystalline hydrates—colorless crystals.

The carbonate oxalates are mixed anion compounds that contain both carbonate (CO3) and oxalate (C2O4) anions. Most compounds incorporate large trivalent metal ions, such as the rare earth elements. Some carbonate oxalate compounds of variable composition are formed by heating oxalates.

<span class="mw-page-title-main">Oxalate phosphate</span> Chemical compound containing oxalate and phosphate anions

The oxalate phosphates are chemical compounds containing oxalate and phosphate anions. They are also called oxalatophosphates or phosphate oxalates. Some oxalate-phosphate minerals found in bat guano deposits are known. Oxalate phosphates can form metal organic framework compounds.

Manganese oxalate is a chemical compound, a salt of manganese and oxalic acid with the chemical formula MnC
2
O
4
. The compound creates light pink crystals, does not dissolve in water, and forms crystalline hydrates. It occurs naturally as the mineral Lindbergite.

An oxalate nitrate is a chemical compound or salt that contains oxalate and nitrate anions (NO3- and C2O42-). These are mixed anion compounds. Some have third anions. Oxalate acts as a ligand, which normally complexes two metal atoms.

<span class="mw-page-title-main">Europium compounds</span> Chemical compounds

Europium compounds are compounds formed by the lanthanide metal europium (Eu). In these compounds, europium generally exhibits the +3 oxidation state, such as EuCl3, Eu(NO3)3 and Eu(CH3COO)3. Compounds with europium in the +2 oxidation state are also known. The +2 ion of europium is the most stable divalent ion of lanthanide metals in aqueous solution. Many europium compounds fluoresce under ultraviolet light due to the excitation of electrons to higher energy levels. Lipophilic europium complexes often feature acetylacetonate-like ligands, e.g., Eufod.

An oxalate chloride or oxalato chloride is a mixed anion compound contains both oxalate and chloride anions.

References

  1. Thompson, Nathan B. A.; Stennett, Martin C.; Gilbert, Matthew R.; Hyatt, Neil C. (2021-01-06). "Nuclear forensic signatures and structural analysis of uranyl oxalate, its products of thermal decomposition and Fe impurity dopant". Journal of Radioanalytical and Nuclear Chemistry. 327 (2): 957–973. doi: 10.1007/s10967-020-07538-2 . ISSN   0236-5731.
  2. Jayadevan, N. C.; Chackraburtty, D. M. (1972-11-15). "The crystal and molecular structure of uranyl oxalate trihydrate". Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry. 28 (11): 3178–3182. Bibcode:1972AcCrB..28.3178J. doi:10.1107/s0567740872007691. ISSN   0567-7408.
  3. Tel, H; Bülbül, M; Eral, M; Altaş, Y (November 1999). "Preparation and characterization of uranyl oxalate powders". Journal of Nuclear Materials. 275 (2): 146–150. Bibcode:1999JNuM..275..146T. doi:10.1016/s0022-3115(99)00119-1. ISSN   0022-3115.
  4. Bryce-Smith, D. (1971). Photochemistry. Royal Society of Chemistry. p. 279. ISBN   978-0-85186-015-2.