Predicting radioactive accessory mineral dissolution during chemical weathering: The radiation dose at the solubility threshold for epidote-group detrital grains from the Yangtze River delta, China

Price, James E.; Wilton, Derek H. C.; Tubrett, Michael; Schneiderman, Jill S.; Fan, Xudong; Peresolak, Katherine

doi:10.1016/j.chemgeo.2014.11.022

Cited by 5 publications

(3 citation statements)

References 121 publications

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“…

D_{α} = 8 N_{238} ([], e^{λ_{238} t} - 1) + 7 N_{235} ([], e^{λ_{235} t} - 1) + 6 N_{232} ([], e^{λ_{232} t} - 1),

where D α is the absorbed α‐dose in events mg −1 ; N 238 , N 235 , and N 232 are the present number of atoms for 238 U, 235 U, and 232 Th, respectively, in atoms mg −1 ; λ 238 , λ 235 , and λ 232 are the decay constants or inverse of half‐life, T 1/2 , in years −1 given by λ i = ln(2)/T 1/2 ; t is the geological age of the mineral or the time that the mineral has been exposed to radiation, in unit of years; the constants 8, 7, and 6 correspond to the number of α‐decays for 238 U, 235 U, and 232 Th, respectively. N 235 is assumed to be (1/139) N 238 based on natural abundances . The number of atoms, N i , is calculated using Equation

N_{i} = \frac{C_{i} \times N_{A}}{A_{i}},

where A i is the atomic weight in g mol −1 and C i is the concentration of the radionuclide.…”

Section: Methodsmentioning

confidence: 99%

“…The energy of the α‐particle, which ranges from 4.0 to 6.0 MeV, is dissipated by ionization over a 10‐ to 20‐μm path and yields ~100–200 atomic displacements. The α‐recoil nucleus, on the other hand, with a lower energy of about 70–100 keV transfers its energy by creating ~1,000–2,000 atomic displacements along ~10‐ to 40‐nm track . The extent of the radiation damage effect in the mineral's crystalline structure is dependent on the α‐radiation dose due to the progressive overlap of α‐recoil collision cascades .…”

Section: Introductionmentioning

confidence: 99%

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Determination of the REE content, geological age, and absorbed alpha dose of allanite mineral from Palawan, Philippines

Dingle

Jecong²,

Hila³

et al. 2019

X-Ray Spectrometry

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Allanite is a common accessory mineral in igneous rocks that contains significant amounts of rare‐earth elements (REEs), thorium (Th), and uranium (U). The presence of Th and U in the allanite exposes it to radiation resulting in radiation damage in its crystal structure and further leads to metamictization. Hence, allanite can be used as a natural analogue to assess the long‐term radiation effects in materials for high‐level nuclear waste disposal. It provides information on the effect of α‐decay on the crystal structure including the stability and integrity of the material. In this study, the absorbed α‐dose of allanite from Ombo, Palawan, Philippines, was estimated from the Th and U content and geological age of the mineral using X‐ray fluorescence and gamma‐ray spectrometry. The amount of Th and REE was measured to be around 1.37 and ~30.4 wt.%, respectively. Radiometric dating using gamma‐ray spectrometry estimated the age of the allanite mineral to be around 24–35 million years. Having obtained the amount of radioactivity and the time of exposure, the corresponding absorbed α‐dose was estimated to be at 2.84 × 1014 α‐decays/mg. Results suggest that the allanite mineral studied has not accumulated significant radiation damage to cause amorphization and still exhibit a crystalline structure. This study may provide data on the properties of allanite or silicate matrices as part of the ongoing studies on silicate minerals as natural analogues.

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“…

D_{α} = 8 N_{238} ([], e^{λ_{238} t} - 1) + 7 N_{235} ([], e^{λ_{235} t} - 1) + 6 N_{232} ([], e^{λ_{232} t} - 1),

N_{i} = \frac{C_{i} \times N_{A}}{A_{i}},

where A i is the atomic weight in g mol −1 and C i is the concentration of the radionuclide.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determination of the REE content, geological age, and absorbed alpha dose of allanite mineral from Palawan, Philippines

Dingle

Jecong²,

Hila³

et al. 2019

X-Ray Spectrometry

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show abstract

“…The remaining ∼99.9% of P 5+ is derived from primary apatite dissolution, and consequently for the LVW, the mineralogic source of the REEs is not the primary P 5+ producer. Rare earth elements also may be sourced from highly soluble silicate minerals such as allanite (e.g., Price et al, 2005Price et al, , 2014. These observations seriously call into question the validity of indiscriminately using REE isotopes as P 5+ tracers.…”

Section: Introductionmentioning

confidence: 99%

Climatic controls on phosphorus concentrations in The Loch, Loch Vale Watershed, Rocky Mountain National Park, Colorado, USA since the last glacial maximum

et al. 2022

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The alpine–subalpine Loch Vale watershed (LVW) of Colorado, USA, has relatively high natural lithogenic P5+ fluxes to surface waters. For 1992–2018, the largest number of stream samples with P5+ concentrations ([P5+]) above detection limits occurred in 2008, corresponding with the highest frost-cracking intensity (FCI). Therefore, relatively cold winters and warm summers with a comparatively low mean annual temperature partly influence stream [P5+]. Sediment cores were collected from The Loch, an outlet lake of the LVW. Iron-, Al-, and Mn-oxide-bound phosphorus (adsorbed and authigenic phosphates; NP) serves as a proxy measurement for paleolake [P5+]. The highest NP in the core occurred during the cold and dry Allerød interstade. The lowest NP concentrations in the core occurred during climatically very wet periods in the Late Pleistocene and Early Holocene. Therefore, [P5+] are highest with relatively cold winters followed by relatively warm summers, relatively low mean annual temperatures, and relatively little rainfall and/or cryospheric melting. Currently the LVW is experiencing warming and melting of the permanent cryosphere with a rapidly declining FCI since 2008. This has the potential to dramatically decrease [P5+] in surface water ecosystems of the LVW, reducing biological productivity, enhancing P-limitation, and increasing ecosystem reliance on aeolian P5+.

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Low Temperature Leaching Behavior of Allanite-(Ce) in Treating an Allanite-Concentrate by Sulfuric Acid

Kärenlampi,

Väänänen,

Roivainen

et al. 2023

J. Sustain. Metall.

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Allanite is a common REE-bearing silicate mineral, which is found in potentially mineable abundances in many areas but has not been economically exploited for the REEs in an industrial scale. Conventional methods, such as sulfuric acid baking at high temperatures (200 to 650 °C) followed by extended water leaching near boiling temperature, have proven effective in decomposing allanite but come with substantial economic and environmental drawbacks. This study presents an alternative approach, investigating the dissolution behavior of allanite at low temperatures through direct treatment of an allanite concentrate with sulfuric acid. Through parametric optimization, the study reveals the practical and selective dissolution of allanite from a relatively coarse concentrate sample (particle size distribution D50 = 327 µm) after a 3-h leaching period with a mild dilute (2 M) H2SO4 solution at 22 °C, yielding overall recoveries of approximately 80% for light REEs and 60% for heavy REEs. The dissolved gangue elements, predominantly derived from allanite (e.g., Th, Fe, Al, Si, and Ca), exhibit contents in the leach solution comparable to or slightly higher than those reported in other studies utilizing acid bake–water leach processes. The notable efficiency of low-temperature sulfuric acid extraction is likely attributed to the heightened chemical reactivity of metamict allanite-(Ce) within the investigated concentrate. While these results are encouraging and demonstrate the potential of low-temperature leaching for allanite concentrates, additional research is necessary before testing the procedure on a larger scale. Graphical Abstract

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Predicting radioactive accessory mineral dissolution during chemical weathering: The radiation dose at the solubility threshold for epidote-group detrital grains from the Yangtze River delta, China

Cited by 5 publications

References 121 publications

Determination of the REE content, geological age, and absorbed alpha dose of allanite mineral from Palawan, Philippines

Determination of the REE content, geological age, and absorbed alpha dose of allanite mineral from Palawan, Philippines

Climatic controls on phosphorus concentrations in The Loch, Loch Vale Watershed, Rocky Mountain National Park, Colorado, USA since the last glacial maximum

Low Temperature Leaching Behavior of Allanite-(Ce) in Treating an Allanite-Concentrate by Sulfuric Acid

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