Efficient Recovery of Gallium and Iron from the Acid Leaching Solution of NdFeB Waste Based on Solvent Extraction

Gallium, a rare metal widely utilized in the electronics industry, has experienced increasing market demand due to the development of the semiconductor industry. Neodymium–iron–boron (NdFeB) waste presents a new potential secondary resource for gallium recovery. In this work, an advanced separation and purification process based on solvent extraction was proposed, realizing stepwise recovery of Ga(III) and Fe(III) from the acid leachate of NdFeB waste. The primary challenges in extracting gallium from the leachate are the enrichment of Ga(III) and the separation between Ga(III) and Fe(III). A multistage counter-current extraction using an organic phase composed of trioctyl/decylamine (N235) and isodecanol was employed to enrich and separate Ga(III) preliminarily. Subsequently, Fe(III) was recovered from the gallium-free leachate. After solvent extraction, stripping, precipitation, and calcination processes, products of Ga2O3 and Fe2O3 with a purity greater than 99% were successfully prepared, and the recovery rates of gallium and iron reached 86% and 92%, respectively. Overall, this study provides an environmentally friendly, economical, and stable technology for recovering Ga (III) and Fe (III) from NdFeB waste. Importantly, this technology offers an effective solution to address the current scarcity of gallium resources.