Récupération de métaux lourds par des extractants organophosphorés et leur mélange synergique. Détermination des complexes (Recovery of heavy metals by organophosphorus extractants and their synergistic mixture. Determination of the complexes)

In the present work, two transition metals (Zn Fe) and uranium are extracted by the tri-n-octylphosphine oxide (TOPO), the hexadecyl-amino-di-methylene-di-phosphonic acid (AHDADMD P) and their synergistic mixture. In zinc extraction by TOPO, a study on the influence of anions bound to a metal (ZnF2, ZnBr2, ZnCl2 and ZnI2) is performed. The results show that regardless of the bound anion, the extraction efficiency of zinc is the same. Similarly, in iron extraction by TOPO, the influence of anions is studied. In fact, different salts such as FeCl3, Fe(NO3)3, Fe2(SO4)3 (hydrated) and FeSO4 are tested. The results show that for trivalent iron, the anion influence is negligible. On the other hand, divalent iron show a completely different behavior compared to Fe (III). In the case of uranium, the effect of the nature of the extraction medium is studied. Here, various acids are tested. The acids used are: HCl, HNO3, H2SO4 and H3PO4. The results show that the best efficiency is obtained with hydrochloric acid, 36% in one step. Besides, the extraction of these metals by AHDADMDP and the TOPO-AHDADMDP mixture are performed