Preparation Of High Resistance, ¦Â-diketone Extractant And Its Ammoniacal Solution Of Copper And Zinc Extraction Performance

"Ammonia Leaching-Solvent Extraction-Electrowinning" process is an ideal means of recovering zinc and copper from low grade ores having basic gangues with high acid consumption. The most important problem of this process is to choose and design some excellent extractants. Considering the drawbacks of commercialβ-diketone extractants (such as:poor stability, poor selectivity of Cu2+ and low extractability of Zn2+), we prepared someβ-diketone molecules with very different structures, systematically studied the relationship between the structures ofβ-diketone molecules and their extractability and stability, and finally found that the excellent sterically hinderedβ-diketone extractant for separation of copper and the best synergistic solvent extraction system for separation of zinc from ammoniacal/ammonium chloride solutions.1.β-diketone molecules with different steric hindrances and trifluoromethyl were prepared by Claisen condensation reactions, including 1-phenyl-2-hexyl-1,3-butanedione (Ⅲ1), 1-phenyl-4-ethyl-1, 3-octanedione (Ⅲ2), 1-(4'-dodecy)phenyl-3-tert-butyl-1,3-propanedione (Ⅲ3), and 1-(4'-dodecy)phenyl-3-trifluoromethyl-1,3-propanedione (Ⅲ4). The structures of these compounds were identified by spectroscopic analytical methods (FTIR,1HNMR, MS).2. The relationships between the structures ofβ-diketone molecules and their extractability and stability were systematically investigated. The results indicated that with the increase of the acidity ofβ-diketone molecules, the extractability of them could be enhanced but the selective ability for separation of Cu2+ could decline. On the other hand, with the increase of the sterically hindered effect ofβ-diketone molecules, the extractability of them could descend but the selectivity for separation of Cu2+ could grow dramatically.3. Comparing the stability ofβ-diketone molecules with different steric effects, the investigation showed that sterically hinderedβ-diketone were more stable thanβ-diketone molecules with lower steric hindrances under industrially operating conditions.4. In many extraction systems of zincβ-diketone chelates, the presence of some neutral organic Lewis bases significantly enhanced the extractability, from which trioctylphosphine oxide (TOPO, B) gave rise to the largest synergism in comparison with other oxygen-containing Lewis bases. The extraction of zinc by TOPO is negligibly small while the extracted complex byⅢ2 (HA) is ZnA2. The synergistic adduct extracted by their mixture is determined to be ZnA2B which has a stability constant of 2.08. The mixture of two extractants shows evident synergistic effects and the synergistic enhancement factor was calculated to be 3.36.