Résumé: Most of the phosphate rocks used commercially contain small quantities of metals such as uranium, lanthanides and yttrium. During the phosphate processing, by reacting the phosphate rocks with sulphuric acid, ca. 30% of lanthanide and yttrium and more than 80% of uranium, present initially in the rocks, end up in phosphoric acid. In this work the overall extraction of uranium and lanthanides from phosphoric acid has been studied. The influence of various factors such H3PO4, SO42:, Fe (III), DOPPA and TOPO concentration on the degree of extraction has been established. Kinetic study shows that the initial extraction rates of uranium and lanthanides are of the same order of magnitude.

Langue: Anglais