Gallium for those LEDs is a byproduct of zinc mining

[SwordfishMining]

I see where they can get more of the gallium we can all use instead of letting it go to landfills. Couple places at least & one is plasma in a lab for the purification.

https://www.sciencedirect.com/science/a ... 6620324746

High-pure gallium is one of the main components for the fabrication of AIIIBV type of semiconductor materials, the most important of that are gallium arsenide, gallium phosphide, and solid solutions based on them [1]. The volume of the world production of such materials exceeds 500 tons per year, while the annual growth rate is more than 10% [2]. The growing demand for gallium-based semiconductor materials is due to the unique electrophysical properties that determine their widespread use as active elements of computers and mobile communications (ultrafast integrated circuits), as well as in solar energy converters, light-emitting diodes and photodetectors of the Visible and IR range, including white-spectrum LEDs that have appeared on the market in recent years, microwave and photodiodes, injection lasers, optical filters and laser modulators [3]. As a result, gallium arsenide next generation semiconductors market is expected to grow to $22 billion by 2026 [4].


Recovery of gallium from leach solutions of zinc refinery residues: https://www.sciencedirect.com/science/a ... 6X21001717

A novel approach was proposed for the extraction of gallium from high-ferric and strongly acidic sulfate leach solutions from zinc refinery residue. The stepwise separation was carried out using N235 and Cyanex 272 in the first and second steps, respectively. The results showed that N235 could selectively remove iron and H2SO4 and provide suitable conditions for the subsequent extraction by Cyanex 272. The co-extracted zinc, gallium, and iron were separated by stepwise stripping. In batch tests, 97.9% of iron was selectively extracted from solutions through three-stage cross-current extraction by using an organic system consisting of 30% (v/v) N235 and 10% (v/v) tributyl phosphate in sulfonated kerosene with an aqueous/organic (A/O) ratio of 1:1, while the percentage extractions of other metals were <3% (the separation factors of βFe/Ga, βFe/Zn, βFe/Cu, and βFe/Cd, were determined to be 4.1×103, 1.7×103, 1.8×103, and 2.3×103, respectively). In the loaded organic system, 99.7% of iron was stripped using 0.5 mol/L H2SO4 followed by treatment with a sodium carbonate solution for regeneration. The raffinate with pH = 2.67 could be directly used for the extraction by Cyanex 272. A total of >99.9% gallium, >99.9% remaining iron, and 49.7% zinc were co-extracted through four-stage counter-current extraction by using an organic system consisting of 30% (v/v) Cyanex 272 in sulfonated kerosene with an A/O ratio of 1:1, while the percentage extractions of other metals (copper and cadmium) were negligible (the separation factors of βGa/Zn, βGa/Fe, βGa/Cu, and βGa/Cd, were determined to be 6.1×103, 2.7×10-1, 3.3×106, and ∞, respectively). Furthermore, >99.9% zinc, 99.7% gallium, and 98.9% iron in the loaded organic system were efficiently separated through a stepwise stripping process by using 6 mol/L HCl, 0.5 mol/L H2SO4, and 0.6 mol/L H2C2O4 (the separation factors of βZn/Ga, βZn/Fe, and βGa/Fe, were determined to be 1.1×106, 4.4×104, and 6.4×104, respectively). Overall, 99.7% of gallium was separated and extracted into the strip liquor, resulting in a concentration of 1502 mg/L.