Fast, Efficient and Environmentally Friendly Extraction of Cu(II) and Zn(II) by Hybrid Silicas Impregnated with Acidic Organic Extractants

Abstract

The extraction of copper and zinc by mesostructured silicas impregnated with organic acidic chelators, an acylisoxazolone 3-phenyl-4-benzoyl-5-isoxazolone (HPBI), an acylpyrazolone 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone (HPMSP) and an organophosphoric acid di-(2-ethylhexyl)-phosphoric acid (DEHPA) was performed in a sulfate medium. Various factors such as the pH of the aqueous phase, the chelators concentration in the silica matrix, the extraction equilibrium time and the extraction capacity of the two cations on silica were studied. The cations were extracted at very acidic pH with very high extraction rates. The stripping of cations was achieved at pHs that were more acidic than those utilized for the extraction by maintaining the structure intact. Finally, their separation was successfully conducted in the cases of the three chelators.