Solvent extraction of molybdenum from various acid media by Alamine 336, Aliquat 336, TOPO, and DEHPA in kerosene was studied. The extraction efficiency of molybdenum by diisobutyl ketone (DIBK), the effects of various parameters like diluents, mineral acids, extractant concentration, and applications of these extractants on molybdenum extraction contained in the uranium-bearing ore solutions were investigated. DIBK used as solvent can indeed extract the molybdenum without adding any extractants in the range of 20-50 mg/L. Molybdenum was extracted by Aliquat 336 in all mineral acids at more than 90%. On the basis of slope analysis, the compositions of the extracted species were expressed by R 3 NH +. HM oO − 4 , MoO 2 (NO 3)2 (DEHPA) 2 , and H 2 MoO 4 .TOPO. Extraction from synthetic solutions showed that molybdenum was extracted by TOPO, Aliquat 336, and Alamine 336 at 99% until [Mo] = 5 g/L. For DEHPA the percentage of extraction was decreased from [Mo] = 2 g/L. The application of these extractants for the extraction efficiency of molybdenum contained in uranium-bearing solutions showed that TOPO, Aliquat 336, and Alamine 336 extracted the molybdenum beyond 60% until the fifth contact. As for DEHPA, it was extracted effectively only at the first contact by 66%.

This study focuses on the liquid-liquid extraction of uranium by anionic extractants of Alamine 336 and Aliquat 336. The objective of this study is to determine the parameters allowing the optimization of the extraction percentage of uranium, and other metals such as molybdenum, zirconium and vanadium. The extraction kinetics of uranium is achieved in 2 minutes. Sulfuric acid solutions are the media per excellence when using Alamine 336 as extractant. However,with Aliquat 336, it is orthophosphoric acid. Uranium is extracted at 99% in a single contact from the ratio: organic phase over aqueous phase (O/A) equals 1. The extraction of uranium with Alamine 336 depends on the initial pH of the aqueous phase as well as the Alamine 336 concentration. Alamine 336 tends to release the uranium and the extracted zirconium until the 3 rd contact to the benefit of the molybdenum due to the natural occurrence of 𝐶𝑙−,𝑁𝑂3 − and 𝐹 − ions in the uranium-bearing solutions which have the tendency of breaking the anion complexes. Vanadium, which is not extracted by Alamine 336 and Aliquat 336, can, in the hydrodynamic conditions of this work, be extracted by increasing the redox potential to 800 mV and pH ≥ 1.

Les sociétés uranifères du Niger utilisent l'Alamine 336 comme extractant. Toutefois, cet extractant se dégrade en amine primaire et secondaire entrainant une baisse du rendement d'extraction. L'objectif de ce travail est d'étudier l'extraction de l'uranium ainsi que certains métaux issus des jus uranifères par l'acide di-2éthylhexylphosphorique (HDEHP) et l'oxyde de trioctylphosphine (TOPO). Après extraction, le dosage des métaux a été effectué par spectrométrie d'absorption atomique pour le vanadium et le molybdène. L'uranium et le zirconium ont été analysés par spectrophotométrie UV-visible. Les meilleurs résultats d'extraction avec E > 99% d'uranium dans divers acides minéraux aux pH ≤ 1 ont été obtenus avec les systèmes TOPO/toluène/HNO 3 et HDEHP/toluène/HNO 3. L'analyse du tracé log D respectivement en fonction du pH et du log [HDEHP] du système Uranium/HDEHP a montré la formation d'un complexe de type [UO 2 (DEHP) 2 ]. La formation d'un complexe de type [UO 2 (NO 3) 2 (TOPO) 2 ] a été obtenue avec le système Uranium/TOPO. Le zirconium et le molybdène ont été extraits avec E > 50% pour tous les extractants. L'extraction du vanadium est efficace aux potentiels redox supérieurs à 800 mV. La faible formation de la 3 ème phase lors de l'extraction et l'efficacité importante d'extraction de l'uranium font du HDEHP une alternative pour ces sociétés.

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