gallium (gallium)

Gallium (Ga, atomic number 31) is a soft, silvery post-transition metal with the unusual property of melting in the hand (melting point 29.76°C). It does not occur as a primary ore and is produced exclusively as a by-product of aluminium smelting (Bayer process bauxite refining produces 50-70 g Ga per tonne of Al2O3) and to a lesser extent zinc smelting. Annual global primary production is approximately 750-800 tonnes — small enough that single-customer disruptions move global prices. India produces negligible primary gallium; the country imports virtually all its requirements.

The dominant end-use is compound semiconductors. Gallium arsenide (GaAs) chips power high-frequency RF amplifiers in mobile phone front-ends and base stations, microwave radar transmitters, photovoltaic concentrator solar cells, and laser diodes for fibre-optic communication. Gallium nitride (GaN) is the substrate of the entire blue and white LED industry — invented in 1993, commercialised at scale through 2000s, and now in roughly 100% of LED lighting — and of high-voltage power electronics in EV chargers and fast chargers. Aluminium gallium nitride (AlGaN) is used in deep-UV LEDs for water disinfection. Roughly 60% of global gallium consumption goes to integrated circuits, 30% to LEDs, and 10% to solar and specialty alloys.

India's Critical Mineral List notified by the Ministry of Mines in 2023 identifies gallium as one of 30 critical minerals. The strategic rationale is acute: 98% of global primary gallium is refined in China, which imposed export controls in August 2023 and September 2024 specifically targeting gallium and germanium — restricting export to specified end-uses with case-by-case licensing. The EU and US have responded by funding domestic Bayer-process recovery upgrades and secondary gallium recovery from end-of-life LEDs and PV modules.

Recovery from e-waste is technically challenging because gallium is dispersed thinly (a smartphone may contain 1-3 mg, an LED bulb 0.1-0.5 mg) and is intimately bonded with arsenic, phosphorus or nitrogen in semiconductor matrices that resist simple acid leaching. Pyrometallurgical concentration in copper smelters captures some gallium in the dust and slime, with subsequent recovery in dedicated solvent-extraction plants. Hydrometallurgy on LED concentrate uses NaOH leach, ion exchange and electrowinning. Capex for a gallium-recovery integrated unit is Rs 50-100 crore at smelter scale — viable only at a few thousand tonnes per year of LED/semiconductor feed, far above what any single Indian e-waste recycler currently aggregates. The pragmatic short-term path is concentration and export of LED and PV-module powders as a strategic material, with domestic recovery developing as the secondary supply chain matures.