Extraction and recovery of the strategic element gallium from an iron mine tailing

Abstract

Strategic elements become essential in recent years due to the extensive technological development of electronics and energy industries. One of the elements of greatest demand is gallium, since its compounds are used as semiconductors mainly in the manufacture of solar panels and LED diodes. Gallium is relatively abundant in the world; however, only a small percentage of these sources can be used as a commercial resource. There are studies in which gallium is recovered from both electronic wastes and mining activities wastes. In this project, gallium was recovered from an iron non-oxidized mine tailing. The tailing has a total content of Ga of approximately 13 mg/kg. The iron tailing was leached with 8 M HCl for 48 h, achieving total dissolution of the Ga present. To separate and concentrate Ga, there were performed solvent extraction experiments with the extractants: tributylphosphate (TBP), trioctylphosphine oxide (TOPO), and a mixture of both, with 3 different diluents: benzene, toluene and hexane to study the effect of these parameters. The results indicate that it was possible to extract up to 100% of Ga with tributylphosphate (TBP) and less than 35% of the Fe present. In the stripping stage it was recovered up to 100% of the extracted Ga with 0.1 M H2SO4.