Preparation of Cyanex 272-containing silica composite by sol-gel method for neodymium adsorption

A kind of silica composite containing bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272) was prepared via a in situ sol-gel approach. 31P solid-state NMR and FT-IR spectra were employed to analyze the structure of the composite. The thermal stability and surface properties were characterized, and the adsorption ability towards trivalent neodymium (Nd(III)) was evaluated by batch experiments. The Cyanex 272 loaded silica composite showed the advantage of an effective adsorption of Nd(III) from low acidic or neutral solutions with a capacity of ∼50 mg/g. The influence of contact time, acidity and initial metal concentration of the stock solutions on the adsorption were comprehensively investigated. (author)