The InGaGe project was presented at the ICHS 2026 – 2nd International Circular Hydrometallurgy Symposium, held on 2-4 September in Belgium through a scientific poster by NTUA. The poster, entitled “Gallium Recovery from Bauxite Residue: Closing the Loop in the Alumina Refining Value Chain” presented NTUA’s work carried out within the project on circular approaches for the recovery of gallium from bauxite residue. The symposium brought together researchers, innovators and industrial stakeholders working on sustainable resource recovery and circular hydrometallurgical technologies, providing an excellent opportunity to exchange knowledge and discuss emerging solutions for critical raw materials.
As part of its broader mission to recover indium (In), gallium (Ga), germanium (Ge), arsenic (As) and antimony (Sb) from industrial waste streams, waste electronics, metallurgical residues and semiconductor scrap, the project is investigating sustainable and circular routes for unlocking the value of materials that are currently underutilised or discarded. Gallium is an essential material used in semiconductors, LED technologies and high-frequency electronics, yet global supply remains highly concentrated. Bauxite residue, which is produced in millions of tonnes annually and contains approximately 50 ppm gallium on average, represents a potentially valuable secondary resource while also posing environmental challenges when stored or landfilled.
The poster introduced several circular bauxite residue valorisation concepts designed to recover aluminium-bearing phases while investigating the pre-concentration of gallium for subsequent recovery. The proposed approaches include sodium carbonate sintering, alkali-assisted roasting, hydrothermal alkaline treatment and selective alkaline leaching. These pathways aim to transform refractory aluminium phases into recoverable streams while assessing how gallium partitions throughout the process and identifying opportunities to concentrate this critical metal in specific process fractions.
In addition to evaluating aluminium extraction and gallium enrichment, the planned research will compare the different processing routes in terms of reagent demand, phase transformations and impurity behaviour. The work will also investigate downstream gallium recovery technologies, including selective precipitation, ion exchange, solvent extraction and electrochemical recovery, with the objective of establishing efficient and sustainable recovery pathways.
Through this research, InGaGe is advancing circular solutions contributing to more resilient European semiconductor sector. The valorisation of industrial residues and the recovery of high-purity materials support resource efficiency and the transition towards more sustainable and circular semiconductor value chain.
