Preparation of silicas impregnated with HPBI, HPMSP and DEHPA and their application in the solid-liquid extraction of Cu(II) and Zn(II)

The synthesis of mesostructured silicas impregnated with 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 undertaken. The different solids were characterized by physico-chemical methods: XRD, FTIR, thermal analysis, TEM, and N2-sorption. The porous integrity of the silica was preserved after impregnation. The amount of ligand was evaluated by UV-Visible analysis of washings, weight loss after calcination and thermal analysis. More than 90% of the ligand used for the impregnation was trapped into the functionalized solids. These materials achieved encouraging extractive performances in removing copper with HPBI below pH 1 and in removing zinc with DEHPA below pH 3 in sulfate media.