الفهرس | Only 14 pages are availabe for public view |
Abstract The present work is mainly concerned with the production of high pure phosphoric acid deductible from the Egyptian wet process phosphoric acid produced by Abu Zaabal fertilizers and chemicals Co. This target would be realized in the same way with obtaining a higher uranium grade metals phosphate fertilizer precipitate. The last by-product, (fertilizer precipitate), have been suggested to be dissolved in the pretreated phosphoric acid, the working phosphoric acid, giving a higher uranium grade phosphoric acid which in turn decrease the uranium separation cost by conventional solvent extraction process. The applied procedures are summarized in using organic miscible solvent for repelling of impurities as metals phosphate precipitate while keeping the majority of phosphorous pentoxide dissolved in the organic layer. It has been suggested that dissolving the metals phosphate precipitate in a pretreated phosphoric acid lead to upgrading the uranium concentration for the conventional solvent extraction by the synergistic mixture of D2EHPA and TOPO in kerosene. For achieving these targets, two organic miscible solvents, acetone and isopropyl alcohol, have been applied. Different factors have been studied in order to reach the optimum conditions for impurities precipitation. These factors include solvent / acid ratio, oxidation reduction potential and precipitating agent addition. The formed precipitate, contains nearly the total uranium content in the working acid with the majority of undesirable other elements e.g. Fe, Cd which was separated and characterized before dissolving in the pretreated phosphoric acid. The second prong of the study is the partially purified phosphoric acid mixed with the organic layer which subjected to more purification by addition of a precipitating agent or passing through ion exchange resin in H+ form e.g. Amberlite IR 120 H. Finally the organic layer is condensed and distilled yielding the free solvent and the purified phosphoric acid. A flow sheet diagram has been suggested and summarized the purification process. |