LAUSR

The targeted capture of platinum from complex and harsh acidic digests such as those platinum-containing secondary resources is essential from the perspectives of green development. Here, a polyamine chelating resin (CMPs-PEI) with excellent selectivity and acid resistance was prepared by nucleophilic substitution reaction using chloromethylated polystyrene as the parent and polyethyleneimine as the modifier. The experimental results revealed that the adsorbent showed excellent adsorption effect on platinum under different acidity, and its maximum adsorption capacity was up to 337nullmg/g at pH 2. More impressively, a rather high capacity of 162.41nullmg/g was achieved in 1 + 1 aqua regia (pH -0.7), which was much higher than other adsorbent materials under the same conditions. In addition, the recovery of platinum by CMPs-PEI in practical platinum-containing iron concentrate abatement solution was 100%. Mechanistic studies showed that the protonated amine groups on CMPs-PEI bound PtCl62- and partially reduced PtCl42- by electrostatic attraction in 1 + 1 aqua regia isoacid solution. Meanwhile, the excellent regeneration performance of CMPs-PEI exhibited in five adsorption-desorption cycles indicated that it showed great potential for green and economic recovery of precious metal ions.