Germanium: A review of its US demand, uses, resources, chemistry, and separation technologies

Germanium (Ge) is one of the critical elements modern technologies, with supply risk, inefficient production, and increased demand. It used in high technology applications such as infrared systems, fiber optics, polymer catalysis, electronics, solar cells. Its demand expected to increase due lack suitable substitutes, increasing for cells 5G networks, continuous trend Ge past 20 years. Globally, 130 tonnes (t) are being produced (2020) primarily China. recovered a byproduct from Zn-refineries coal fly ash. Yet very low amount (<3%) contained Zn-ores ash worldwide, which suggests that criticality economical efficient extraction recovery process rather than resources. Worldwide, it estimated contain 7–13 kt Ge, ash, 25–112 kt. The production involves leaching followed by chlorination-distillation, precipitation, solvent extraction, ion flotation, supported liquid membranes, exchange, or solid-phase extraction. Leaching Zn-refinery residues done mineral acids, whereas achieved organic ligands. different common metal cations, exists neutral species acidic pH (1–7). Thus, ligands form anionic germanium-ligand complexes ion-exchange processes so can be separated through anion-exchange. Alternatively, chelating extractants, resins, ligand functionalized adsorbents (SPE) recover Ge. primary challenges hydrometallurgical energy chemical requirements precipitation/chlorination-distillation, consumption, impurities co-extraction, waste stream generation selective high-capacity SPE. An improved, efficient, method, utilizing unconventional resources, reduce risk. SPE has various advantages over other processes, makes an attractive option efficiently economically.