Details

Autor(en) / Beteiligte

• Gabitov, Rinat
• Migdisov, Artas
• Nguyen, Anh
• Van Hartesveldt, Noah
• Perez-Huerta, Alberto
• Sadekov, Aleksey
• Sauer, Kirsten Benedict
• Baker, Jason
• Paul, Varun
• Caporuscio, Florie
• Xu, Hongwu
• Roback, Robert

Titel

Uptake of uranium by carbonate crystallization from reduced and oxidized hydrothermal fluids

Ist Teil von

• Chemical geology, 2021-03, Vol.564, p.120054, Article 120054

Ort / Verlag

United States: Elsevier B.V

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• This work evaluated the immobilization of uranium (U) through incorporation into calcite under reduced and oxidized conditions. We investigated how much U could be entrapped by calcite crystallizing in chloride solutions in autoclaves at temperatures from 162 to 300 °C. The oxidation state of U was set by controlling oxygen fugacity via redox buffers. Uranium was introduced into calcite growth media as a solid oxide compound or U aliquot. We found the uptake of tetravalent U by calcite is higher than that of hexavalent U by up to four orders of magnitude. We estimate that crystallization of a few mg of calcite immobilizes all dissolved U when 1 kg of solution is saturated with UO2 under reduced hydrothermal conditions. •Aragonite transforms to calcite and uptakes U from solutions at 162–350 °C.•U4+ has a higher affinity of incorporating into calcite compared with U6+.•Calcite has strong potential in immobilizing U4+ at 250-3000 °C.