Due to the fact that uranium and ferric iron are co-extracted by D2EHPA (Di-2-ethyl hexyl phosphoric acid), different trials were investigated to overcome this difficulty. These trials involved the use of masking and reducing agents as well as the application of Di-2-ethyl hexyl phosphoric acid-Tri octyl phosphine oxide (D2EHPA/ TOPO) as a synergism. The obtained data revealed that the separation of uranium from ferric iron sulfate leach liquor of G.Gattar ore material is not satisfactory by using tartaric acid, oxalic acid, DTPA (Di ethylene tri amine penta acetic acid) and NaF as a masking agents or ascorbic acid as a reducing agent. On the contrary, the addition of these agents increased the extraction of ferric iron with great pronounce acceleration effect. This can be referred to the salting out effect. However, when using ascorbic acid as a reducing agent, the iron extraction efficiency was decreased with no simultaneous effect upon uranium extraction efficiency. On the other hand, the investigation of the D2EHPA/TOPO synergism revealed that successful separation of uranium from ferric iron was achieved by increasing TOPO concentration. The uranium extraction reached completion when using 0.1 M D2EHPA and 0.05 M TOPO, at a contact time of 10 minutes. In the meantime the ferric iron extraction efficiency reached as low as 10%. |
