Uranyl oxalate (UO₂C₂O₄) is a pale yellow powdered

uranyl The uranyl ion with the chemical formula has a linear structure with short U–O bonds, indicative of the presence of multiple bonds between uranium and oxygen, with uranium in the oxidation state +6. Four or more ligands may be bound to the u ...

salt. It is often encountered in industrial

nuclear process In nuclear physics and nuclear chemistry, a nuclear reaction is a process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides. Thus, a nuclear reaction must cause a transformation ...

es at both the front and back-end of the

nuclear fuel cycle The nuclear fuel cycle, also known as the nuclear fuel chain, describes the series of stages that nuclear fuel undergoes during its production, use, and recycling or disposal. It consists of steps in the ''front end'', which are the preparation o ...

. Due to its

hygroscopicity Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance ...

, uranyl oxalate rarely exists in the dehydrated state and is usually instead found in the trihydrate form (UO₂C₂O₄·3H₂O) at room temperature. At room temperature, the powder exhibits a

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in t ...

crystal structure in the ''P''2₁/''c''

space group In mathematics, physics and chemistry, a space group is the symmetry group of a repeating pattern in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of the pattern that ...

Production

Uranyl oxalate trihydrate can be produced by the reaction of

uranyl nitrate Uranyl nitrate is a water-soluble yellow uranium salt with the formula . The hexa-, tri-, and dihydrates are known. The compound is mainly of interest because it is an intermediate in the preparation of nuclear fuels. In the nuclear industry, it ...

hexahydrate with

oxalic acid Oxalic acid is an organic acid with the systematic name ethanedioic acid and chemical formula , also written as or or . It is the simplest dicarboxylic acid. It is a white crystalline solid that forms a colorless solution in water. Its name i ...

. Uranyl oxalate has been used in

actinometer An actinometer is an instrument that can measure the heating power of radiation. Actinometers are used in meteorology to measure solar radiation as pyranometers, pyrheliometers and net radiometers. An actinometer is a chemical system or physical ...

References

{{Oxalates Oxalates Uranyl compounds