Synthesis of polyacrylate-divinylbenzene hydroxamic resins and its gallium adsorption performance in sulfuric acid solution

Abstract

In this study, the adsorption behavior of gallium ions on a synthesized hydroxamic acid resin from sulfuric acid solution was investigated, aiming to recover Ga directly from pressure leaching solution in zinc hydrometallurgical plant. Hydroxamic acid chelating resin (HA-PDR) was prepared by introducing hydroxamic acid groups into the pre-made polyacrylate resin (PDR) with methyl ester group through hydroxylamine reaction. Polyacrylate-divinylbenzene hydroxamic resins with a nitrogen content of up to 3.85 % were obtained at a divinylbenzene (DVB) content of 13 % and an optimal raw material ratio of NH2OH·HCl: NaOH: −CH3 = 4:4.5:1 (molar ratio). The obtained materials was characterized using FTIR, XPS and SEM to verify the successful introduction of hydroxamic acid groups. The results of adsorption experiments showed that the adsorption capacity of 27.65 mg/g could be obtained with a chemical, multilayered, and heterogeneous adsorption process, and film diffusion and intra-particle diffusion rate controlled mainly the adsorption efficiency. It has been proven that polyacrylate-divinylbenzene hydroxamic resins has extremely high adsorption selectivity for gallium in sulfuric acid solution, and the desorption effect is obvious, which can be applied promisingly in the industrial development of gallium extraction technology from zinc leaching residue in sulfuric acid system.