Silica-Based 2-AminomethylpyridineFunctionalizedAdsorbent for Hydrometallurgical Extraction of Low-Grade Copper Ore.

A silica-based 2-aminomethylpyridine functionalized adsorbentwassynthesized to extract copper. Characterization of the adsorbent wascarried out to determine the surface morphology, specific surfacearea, pore size, and grafting ratio of 2-aminomethylpyridine groups.The adsorption selectivity of the adsorbent for Cu(II) ions was 1353times higher than that for Fe(III) ions. The adsorption capacity forCu(II) ions maintained a stable value of 0.53 mmol/g with and withoutperturbation of Fe(III) ions. Density functional theory (DFT) calculationsrevealed a mechanism of selective adsorption of copper, through theformation of 2-aminomethylpyridine-Cu(II) complexes. Semi-industrialscale experiments revealed that Cu(II) ions in the acidic leachateof low-grade copper ore could be efficiently extracted by the adsorbenteven in perturbation of substantial amounts of Fe(III) and other metalions. Based on the adsorbent, a new process for copper hydrometallurgicalextraction was developed, in which the adverse environmental impactsin traditional solvent extraction processes could be avoided. [ABSTRACT FROM AUTHOR]