Gallium is not produced in the United States and there is no government stockpile. U.S. gallium demand is satisfied by imports, with domestic import sources from 2014 to 2017 as: China, 32%; United Kingdom, 28%; Germany, 15%; Ukraine, 14%; and other, 11%. In 2018, gallium metal imports from China to the United States increased by about 60% from those of 2017 and primary low-grade (99.99%-pure) gallium prices in China increased by about 40% in 2018.
World demand for gallium is expected to remain high as gallium is particularly important for clean energy technologies. In 2018, Integrated Circuits accounted for 68% of U.S. gallium consumption, optoelectronic devices accounted for 30%, and research and development accounted for 2%.
The small market for gallium creates little incentive for refiners of zinc, copper, and aluminum ores to invest in improvements to increase the byproduct recovery of gallium. At the same time, China controls more than 80% of worldwide primary gallium capacity. Because of the likelihood of rapid growth in the areas of photovoltaics and clean energy technologies, there is a very real chance of a bottleneck in the gallium supply pipeline. It cannot be disputed that trade wars with China could limit the ability of the U.S. to secure necessary gallium resources in the future.
Beyond the basics above, what else should we know about gallium? Check out the 20 interesting facts below!
- The existence of gallium was predicted in 1871 by Dmitri Mendeleev, the Russian chemist who published the first periodic table of the elements. Mendeleev noted a gap in his table and named the missing element “eka-aluminum” because he determined that its location was one place away from aluminum in the table.
- The French chemist Paul-Emile Lecoq de Boisbaudran discovered gallium in sphalerite (a zinc-sulfide mineral) in 1875 using spectroscopy. He named the element “gallia” after his native land of France (formerly Gaul; in Latin, “Gallia”).
- Gallium first became recognized as a critical mineral resource during World War II and was used in the core of the first atomic bomb to help stabilize the plutonium crystal structure of a gallium-plutonium alloy developed as part of the Manhattan Project.
- The development of a gallium-based direct band-gap semiconductor in the 1960s led to what is now one of the most well-known applications for gallium-based products – the manufacture of smartphones and data-centric networks.
- No primary (low-grade, unrefined) gallium has been recovered in the United States since 1987.
- In 2017, the value of worldwide radio frequency GaAs device consumption increased by 7% due to a growing wireless telecommunications infrastructure in Asia, growth of third- and fourth-generation smartphones (which use 10 times the amount of GaAs), and strong demand in military radar and communications applications.
- In May 2018, the U.S. Department of the Interior, in coordination with other executive branch agencies, published a list of 35 critical minerals (83 FR 23295), including gallium. This list was developed to serve as an initial focus, pursuant to Executive Order 13817, ‘‘A Federal Strategy to Ensure Secure and Reliable Supplies of Critical Minerals” (82 FR 60835).
- Gallium occurs in very small concentrations in ores of other metals. Most gallium is produced as a byproduct of processing bauxite, with the remainder produced from zinc processing residues.
- The average gallium content of bauxite is 50 parts per million. Some zinc ores contain up to 50 parts per million gallium. However, less than 10% of the gallium in bauxite and zinc resources is potentially recoverable.
- Gallium is the 34th most abundant element found in Earth’s crust with an abundance of 19 parts per million by weight. In our solar system, gallium has an abundance of 40 parts per billion by weight.
- Gallium is a liquid across a wider range of temperatures than any other element. Solid gallium has a low melting temperature (~29 degrees Celsius, or °C) and an unusually high boiling point (~2,204 °C).
- Unlike most substances, gallium expands when it freezes.
- Gallium is a silvery, glass-like, soft metal.
- The crystal structure of gallium is orthorhombic.
- In the periodic table, gallium lies in group 13 (former group 3A), between aluminum and indium, and in the same group as thallium. Consequently, its properties resemble those of these three elements. In addition, it is situated in period 4, between zinc and germanium. It is also said to be one of the “poor metals” – elements located between the transition metals and metalloids in the periodic table.
- Gallium can form a number of compounds. Chief among them in economic importance are: Gallium(III) arsenide (GaAs), Gallium(III) hydroxide (Ga(OH)3), Gallium(III) nitride (GaN), and Gallium(III) phosphide (GaP).
- Analog integrated circuits and optoelectronic devices (laser diodes, light-emitting diodes [LEDs], photo detectors, and solar cells) are the primary applications for gallium, with essential use found in aerospace and defense applications, high-performance computers, industrial equipment, medical equipment, and telecommunications equipment.
- The Neutrino Observatory in Italy uses large amounts of gallium trichloride to study solar neutrinos produced in the sun.
- Gallium is used to “wet” glass or porcelain to create brilliant mirrors.
- An alloy of gallium, indium, and tin (trade name Galinstan) is used in high-grade thermometers to replace the obviously problematic mercury.