Extraction of Ga(III) by Di-(2-ethylhexyl)phosphoric acid (D2EHPA)-Modified XAD-4 Resins Prepared by Solvent-Nonsolvent Modification

Gallium (Ga) is one of the most important elements that are widely used in electronic devices. The development of Ga recovery technology is an important issue for resource recycling. In this study, di-(2-ethylhexyl)phosphoric acid (D2EHPA)-modified XAD-4 resin (DMR) is prepared by the solvent-nonsolvent method. The evolution of pore characteristics demonstrates that the solvent-nonsolvent treatment is advantageous for the immobilization of D2EHPA in XAD-4 resin. The adsorption isotherm of Ga(III) can be described by the Langmuir isotherm model. The Ga(III) adsorption kinetics follows the pseudo-second-order model. The immobilized D2EHPA shows good stability. The reusability study indicates that DMR can maintain the performance after three cycles of adsorption and stripping. The results for the treatment of a practical leaching solution from GaN/Al₂O₃ wafer further demonstrate that DMR can be applied effectively for Ga(III) recovery.