Thermodynamics of uranyl minerals: Enthalpies of formation of uranyl oxide hydrates

Karrie Ann Kubatko; Katheryn Helean; Alexandra Navrotsky; Peter C. Burns

doi:10.2138/am.2006.1856

Thermodynamics of uranyl minerals: Enthalpies of formation of uranyl oxide hydrates

Karrie Ann Kubatko, Katheryn Helean, Alexandra Navrotsky, Peter C. Burns

Research output: Contribution to journal › Article › peer-review

45 Scopus citations

Abstract

The enthalpies of formation of seven uranyl oxide hydrate phases and one uranate have been determined using high-temperature oxide melt solution calorimetry: [(UO₂)₄O(OH)₆] (H₂O)₅, metaschoepite; β-UO₂ (OH)₂; CaUO₄; Ca(UO₂)₆ O₄(OH)₆(H₂O)₈, becquerelite; Ca(UO₂)₄O₃(OH)₄ (H₂O)₂; Na(UO₂)O(OH), clarkeite; Na₂(UO₂)₆O₄ (OH)₆(H₂O)₇, the sodium analogue of compreignacite, and Pb₃(UO₂)₈ O₈(OH)₆(H₂O)₂, curite. The enthalpy of formation from the binary oxides, ΔH_f-ox, at 298 K was calculated for each compound from the respective drop solution enthalpy, ΔH_ds. The standard enthalpies of formation from the elements, ΔH_f^o, at 298 K are -1791.0±3.2, -1536.2±2.8, -2002.0± 3.2, -11389.2±13.5, -6653.1±13.8, -1724.7±5.1, -10936.4± 14.5, and -13163.2±34.4 kJ/mol, respectively. These values are useful in exploring the stability of uranyl oxide hydrates in auxiliary chemical systems, such as those expected in U-contaminated environments.

Original language	English (US)
Pages (from-to)	658-666
Number of pages	9
Journal	American Mineralogist
Volume	91
Issue number	4
DOIs	https://doi.org/10.2138/am.2006.1856
State	Published - Apr 2006
Externally published	Yes

Keywords

Becquerelite
Calorimetry
Compreignacite
Curite
Enthalpy
Metaschoepite
Uranium
Uranyl

ASJC Scopus subject areas

Geophysics
Geochemistry and Petrology

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10.2138/am.2006.1856

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@article{51328ab8e3a74768b5c5c970b6109a8c,

title = "Thermodynamics of uranyl minerals: Enthalpies of formation of uranyl oxide hydrates",

abstract = "The enthalpies of formation of seven uranyl oxide hydrate phases and one uranate have been determined using high-temperature oxide melt solution calorimetry: [(UO2)4O(OH)6] (H2O)5, metaschoepite; β-UO2 (OH)2; CaUO4; Ca(UO2)6 O4(OH)6(H2O)8, becquerelite; Ca(UO2)4O3(OH)4 (H2O)2; Na(UO2)O(OH), clarkeite; Na2(UO2)6O4 (OH)6(H2O)7, the sodium analogue of compreignacite, and Pb3(UO2)8 O8(OH)6(H2O)2, curite. The enthalpy of formation from the binary oxides, ΔHf-ox, at 298 K was calculated for each compound from the respective drop solution enthalpy, ΔHds. The standard enthalpies of formation from the elements, ΔHfo, at 298 K are -1791.0±3.2, -1536.2±2.8, -2002.0± 3.2, -11389.2±13.5, -6653.1±13.8, -1724.7±5.1, -10936.4± 14.5, and -13163.2±34.4 kJ/mol, respectively. These values are useful in exploring the stability of uranyl oxide hydrates in auxiliary chemical systems, such as those expected in U-contaminated environments.",

keywords = "Becquerelite, Calorimetry, Compreignacite, Curite, Enthalpy, Metaschoepite, Uranium, Uranyl",

author = "Kubatko, {Karrie Ann} and Katheryn Helean and Alexandra Navrotsky and Burns, {Peter C.}",

year = "2006",

month = apr,

doi = "10.2138/am.2006.1856",

language = "English (US)",

volume = "91",

pages = "658--666",

journal = "American Mineralogist",

issn = "0003-004X",

publisher = "Mineralogical Society of America",

number = "4",

}

TY - JOUR

T1 - Thermodynamics of uranyl minerals

T2 - Enthalpies of formation of uranyl oxide hydrates

AU - Kubatko, Karrie Ann

AU - Helean, Katheryn

AU - Navrotsky, Alexandra

AU - Burns, Peter C.

PY - 2006/4

Y1 - 2006/4

N2 - The enthalpies of formation of seven uranyl oxide hydrate phases and one uranate have been determined using high-temperature oxide melt solution calorimetry: [(UO2)4O(OH)6] (H2O)5, metaschoepite; β-UO2 (OH)2; CaUO4; Ca(UO2)6 O4(OH)6(H2O)8, becquerelite; Ca(UO2)4O3(OH)4 (H2O)2; Na(UO2)O(OH), clarkeite; Na2(UO2)6O4 (OH)6(H2O)7, the sodium analogue of compreignacite, and Pb3(UO2)8 O8(OH)6(H2O)2, curite. The enthalpy of formation from the binary oxides, ΔHf-ox, at 298 K was calculated for each compound from the respective drop solution enthalpy, ΔHds. The standard enthalpies of formation from the elements, ΔHfo, at 298 K are -1791.0±3.2, -1536.2±2.8, -2002.0± 3.2, -11389.2±13.5, -6653.1±13.8, -1724.7±5.1, -10936.4± 14.5, and -13163.2±34.4 kJ/mol, respectively. These values are useful in exploring the stability of uranyl oxide hydrates in auxiliary chemical systems, such as those expected in U-contaminated environments.

AB - The enthalpies of formation of seven uranyl oxide hydrate phases and one uranate have been determined using high-temperature oxide melt solution calorimetry: [(UO2)4O(OH)6] (H2O)5, metaschoepite; β-UO2 (OH)2; CaUO4; Ca(UO2)6 O4(OH)6(H2O)8, becquerelite; Ca(UO2)4O3(OH)4 (H2O)2; Na(UO2)O(OH), clarkeite; Na2(UO2)6O4 (OH)6(H2O)7, the sodium analogue of compreignacite, and Pb3(UO2)8 O8(OH)6(H2O)2, curite. The enthalpy of formation from the binary oxides, ΔHf-ox, at 298 K was calculated for each compound from the respective drop solution enthalpy, ΔHds. The standard enthalpies of formation from the elements, ΔHfo, at 298 K are -1791.0±3.2, -1536.2±2.8, -2002.0± 3.2, -11389.2±13.5, -6653.1±13.8, -1724.7±5.1, -10936.4± 14.5, and -13163.2±34.4 kJ/mol, respectively. These values are useful in exploring the stability of uranyl oxide hydrates in auxiliary chemical systems, such as those expected in U-contaminated environments.

KW - Becquerelite

KW - Calorimetry

KW - Compreignacite

KW - Curite

KW - Enthalpy

KW - Metaschoepite

KW - Uranium

KW - Uranyl

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DO - 10.2138/am.2006.1856

M3 - Article

AN - SCOPUS:26944480287

VL - 91

SP - 658

EP - 666

JO - American Mineralogist

JF - American Mineralogist

SN - 0003-004X

IS - 4

ER -

Thermodynamics of uranyl minerals: Enthalpies of formation of uranyl oxide hydrates

Abstract

Keywords

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