Highly selective removal of Ga3+ ions from Al3+/Ga3+ mixtures using graphite oxide

In this paper, we present a simple solution to a major technological issue, the extraction of gallium from bauxite ore and aluminium–gallium separation. Due to its extremely large surface area and oxygen functional groups, graphite oxide was used for the highly selective sorption of Ga3+ from Al3+/Ga3+ mixtures. Graphite oxide prepared according to the Hummers method has various oxygen functionalities which form coordination bonds with metal ions. Sorption capacity and selectivity of graphite oxide towards Al3+, Ga3+ and their mixtures were investigated. Since the results of these experiments revealed much higher affinity of graphite oxide to Ga3+ ions, we tested the procedure on aluminium–gallium oxide prepared by Bayer process from real bauxite ore. In this case too, the results showed that Ga3+ accumulated on the graphite oxide surface. This suggests that high sorption selectivity can be used for the extraction of gallium on an industrial scale and, thus, as a rich source of gallium for the semiconductor industry.