The use of a soaking procedure combined with the sintering process to reach a high cerium content in a cerium-bearing Y-britholite

Kamel, N.; Aït-Amar, H.; Zahri, A.

doi:10.1016/j.pnucene.2007.03.002

Cited by 6 publications

(12 citation statements)

References 37 publications

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“…R 1 α Zero-order equation (2) 0.9090 (2) Polany-Winger equation [37]. R 2 1 À(1 Àα) 1/2 Phase boundary controlled reaction 0.9090 (3) Wagner equation [41,42]. R 3 1 À(1 Àα) 1/3 0.9609 (4) Ginstling-Brounshtein equation.…”

Section: Synthesis Of Sry 2 (Sio 4 ) 3 O Phasementioning

confidence: 99%

“…The values of a and b coefficients depend on the valence of M, X and Y species. This structure provides apatites with great capacity to form solid solutions and, particularly, to accept several substitutes (Me=Na, K and possibly Mg; XO 4 =CO 3 2 À and Y=1/2 CO 3 2À ) [2][3][4][5][6][7][8]. The most common apatite compound in nature is Ca 10 (PO 4 ) 6 F 2 , which crystallizes in the hexagonal system with the space group P6 3 /m.…”

Section: Introductionmentioning

confidence: 99%

“…The CO 3 2 À ions substitute both PO 4 3 À and OH À sites of the apatite lattice. The substitutions of PO 4 3 À and OH À by CO 3 2 À are referred to as B-and A-type, respectively.…”

Section: Introductionmentioning

confidence: 99%

“…The CO 3 2 À ions substitute both PO 4 3 À and OH À sites of the apatite lattice. The substitutions of PO 4 3 À and OH À by CO 3 2 À are referred to as B-and A-type, respectively. Since CO 3 2 À anion has a planar structure differing from the linear structure of OH À and from tetragonal structure of PO 4 3 À , the numerous geometric configurations are possible for CO 3 2 À substituting for both ions [19][20][21].…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the structure of some natural britholite samples was found to remain stable, although it contained some radioactive elements or fission products. Their general chemical formula is Ca 4À x REE 6 þ x (PO 4 ) 5 [3,10,[26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Preparation, kinetics of sinter-crystallization and properties of hexagonal strontium-yttrate-silicate apatite phase: SrY4[SiO4]3O

Ptáček

Bartoníčková

Švec

et al. 2015

Ceramics International

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Section: Synthesis Of Sry 2 (Sio 4 ) 3 O Phasementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…The CO 3 2 À ions substitute both PO 4 3 À and OH À sites of the apatite lattice. The substitutions of PO 4 3 À and OH À by CO 3 2 À are referred to as B-and A-type, respectively.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Preparation, kinetics of sinter-crystallization and properties of hexagonal strontium-yttrate-silicate apatite phase: SrY4[SiO4]3O

Ptáček

Bartoníčková

Švec

et al. 2015

Ceramics International

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Geochemical implications of uranium-bearing thucholite aggregates in the Upper Permian Kupferschiefer shale, Lubin district, Poland

Syczewski,

Panajew,

Marynowski

et al. 2024

Miner Deposita

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New inorganic and organic geochemical data from thucholite in the Upper Permian (Wuchiapingian) Kupferschiefer (T1) shale collected at the Polkowice-Sieroszowice Cu-Ag mine in Poland are presented. Thucholite, which forms spherical or granular clusters, appears scattered in the T1 dolomitic shale at the oxic-anoxic boundary occurring within the same shale member. The composition of thucholite concretions and the T1 shale differs by a higher content of U- and REE-enriched mineral phases within the thucholite concretions compared to the T1 shale, suggesting a different mineralising history. The differences also comprise higher Ntot, Ctot, Htot, Stot contents and higher C/N, C/S ratios in thucholite than in the T1 shale. The hydrocarbon composition of the thucholite and the surrounding T1 shale also varies. Both are dominated by polycyclic aromatic compounds and their phenyl derivatives. However, higher abundances of unsubstituted polycyclic aromatic hydrocarbons in the thucholite are indicative of its pyrogenic origin. Pyrolytic compounds such as benz[a]anthracene or benzo[a]pyrene are more typical of the thucholite than the T1 shale. Microscopic observations of the thucholite and its molecular composition suggest that it represents well-rounded small charcoal fragments. These charcoals were formed during low-temperature combustion, as confirmed by semifusinite reflectance values, indicating surface fire temperatures of about 400 °C, and the absence of the high-temperature pyrogenic polycyclic aromatic hydrocarbons. Charred detrital particles, likely the main source of insoluble organic matter in the thucholite, migrated to the sedimentary basin in the form of spherical carbonaceous particulates, which adsorbed uranium and REE in particular, which would further explain their different contents and sorption properties in the depositional environment. Finally, the difference in mineral content between thucholite and the T1 shale could also have been caused by microbes, which might have formed biofilms on mineral particles, and caused a change in the original mineral composition.

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The field of solid solutions in ternary system of synthetic apatite-type alkaline earth element-yttrium-silicate oxybritholite phases of the composition: AEE Y10−[SiO4]6O3−0.5, where AEE=Ca, Sr and Ba

Ptáček

Opravil

Šoukal

et al. 2016

Ceramics International

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The use of a soaking procedure combined with the sintering process to reach a high cerium content in a cerium-bearing Y-britholite

Cited by 6 publications

References 37 publications

Preparation, kinetics of sinter-crystallization and properties of hexagonal strontium-yttrate-silicate apatite phase: SrY4[SiO4]3O

Preparation, kinetics of sinter-crystallization and properties of hexagonal strontium-yttrate-silicate apatite phase: SrY4[SiO4]3O

Geochemical implications of uranium-bearing thucholite aggregates in the Upper Permian Kupferschiefer shale, Lubin district, Poland

The field of solid solutions in ternary system of synthetic apatite-type alkaline earth element-yttrium-silicate oxybritholite phases of the composition: AEE Y10−[SiO4]6O3−0.5, where AEE=Ca, Sr and Ba

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