Química Nova (Jan 2008)

Extração líquido-líquido de urânio(VI) do colofanito de itataia (Santa Quitéria, Ceará) por extratantes orgânicos em presença de ácido fosfórico Liquid-liquid extraction of uranium(VI) from colofanite of itataia (Santa Quitéria, Ceará) by organic extractants in the presence of phosphoric acid

  • Valeria Aparecida Leitão Ribeiro,
  • Júlio Carlos Afonso,
  • Glória Regina da Silva Wildhagen,
  • José Waldemar Silva Dias da Cunha

DOI
https://doi.org/10.1590/S0100-40422008000800042
Journal volume & issue
Vol. 31, no. 8
pp. 2159 – 2164

Abstract

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This work describes the liquid-liquid extraction of uranium after digestion of colofanite (a fluoroapatite) from Itataia with sulfuric acid. The experiments were run at room temperature in one stage. Among the solutions tested the highest distribution coefficient (D > 60) was found for 40%vol. DEHPA (di(2-ethyl-hexyl)phosphoric acid) + 20% vol. TOPO (trioctylphosphine oxide) in kerosene. Thorium in the raffinate was quantitatively extracted by TOPO (0.1% vol.) in cyclohexane. Uranium stripping and separation from iron was possible using 1.5 mol L-1 ammonium or sodium carbonate (room temperature, one stage). However, pH control is essential for a good separation.

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