The element that became known as gallium was another of those elements (like rhenium - see Rhenium: Son of Moly) predicted by Dmitri Mendeleev, the Russian chemist, when he constructed the periodic table, but not yet, at that time, found.
Nestled, as it is, in between zinc on its left, germanium on its right and below aluminum, it took the French chemist Paul Emile Lecoq de Boisbaudran until 1875 (some six or so years after the discovery of the periodic table) to find this elusive metal.
Boisbaudran pinned down the metal first spectroscopically (spectroscopy was one of his specialties) and only thereafter did he actually isolate the metal itself - a minute amount extracted from a number of tons of zinc ore! Being a Frenchman, and patriotic, he named the metal gallium after the ancient name for his country - Gallia.
Again, like rhenium, gallium does not exist in its pure metallic form in nature. Unlike rhenium, it may be scarce, but it is certainly not rare. In fact, its concentration in the Earth's crust is similar to that of arsenic and lead. As in the periodic table, it is most usually found in association with its neighbors there: aluminum, germanium and zinc. These days, the alumina industry is the major source of primary gallium.
Some Physical Properties
While gallium may have been a little slippery and difficult to pin down at first, now that it has been, it remains slippery in another, totally different, way. Like mercury (and, indeed, caesium, francium and rubidium), gallium is a liquid around room temperature - albeit a pretty warm room! Its melting point is actually only 85.58°F (29.76°C). This means that, if you held a lump of the metal in your hand, it would melt. Unlike mercury, however, at high temperatures it has a low vapor pressure.
On the other hand, one of gallium's peculiar characteristics is that it can be easily supercooled, i.e., cooled to below its freezing point without becoming a solid. And its boiling point is high, at 3,999°F (2,204°C). Indeed, it has the longest liquid range of all elements.
And even when it's solid, gallium is so soft you can cut it with a knife.
When combined with the elements arsenic and nitrogen, the resulting gallium compounds - gallium arsenide [GaAs] and gallium nitride [GaN], respectively - display both significant optoelectronic and semiconductor properties. It is here that the main importance of the metal in our lives now lies.
Both gallium arsenide and gallium nitride are used in, amongst other things, integrated circuits (chips/microchips) - especially for mobile phones, LEDs, laser diodes, photodetectors and solar cells. Gallium nitride is, in addition, used in amplifiers for cable TV and wireless communications base stations, certain advanced transistors, highly specialized chips and, perhaps a little closer to home, specifically in the blue laser diodes used in Blu-ray DVD devices.
According to the latest (published in January 2008) U.S. Geological Survey (USGS) mineral commodity summary for gallium, consumption of these two compounds accounted for some 98% of U.S. domestic consumption of the metal.
US Gallium Consumption - 2007
Gallium metal is used in high-temperature thermometers, to create high-quality mirrors, and in certain dental applications - often as a substitute for mercury. It is also used, together with rare earth metals, in magnets, and in certain catalysts.
Whence The Gallium?
Total global production of gallium is probably only around 220 tonnes a year, with a significant portion of that coming from secondary production, or the recycling of GaAs scrap.
Most primary gallium is extracted from the smelter "liquor" resulting from the Bayer process used to produce alumina from bauxite (in which gallium is, essentially, a contaminant).
The major primary gallium-producing countries (and companies) are:
- China - Aluminum Corporation of China (aka Chalco/Chinalco) (Bloomberg Ticker - ACH:US)
- Germany - Recapture Metals Ltd/Mining & Chemical Products Limited (MCP)
- Japan - Dowa Holdings (Bloomberg Ticker - DWMNF:US)
- Ukraine - Mykolayivsky Hlynozemny Zavod
Other primary gallium-producing countries include Hungary, Kazakhstan, Russia and Slovakia.
Figures for primary gallium production (and, indeed, any gallium production, whether primary or secondary), are extraordinarily difficult to come by. As the USGS understatedly says: "Data on world production of primary gallium are unavailable because data on the output of the few producers are considered to be proprietary."
Some indication can, however, be gleaned from those figures that are available. (The USGS estimated primary gallium production in 2007 was 80 tonnes.)
In a report published in February 2008, Chalco said that: "In 2004, Chalco recycled the concomitant gallium of 29.7 tons from the spent liquor of alumina production, accounting for 30% of the total gallium production in the world in that year and turning Chalco into the largest gallium supplier in the world, with total value of 80 million Yuan created." It would, I believe, be safe to assume that Chinese production figures have risen, at least moderately, since then.
Recapture Metals describes the gallium production facility it runs in a joint venture with MCP (both are private companies) at Stade in Germany, as having a capacity of some 35 tonnes a year and a planned output for 2008 of 25 tonnes. Their plan was most probably met, or even exceeded.
Recent figures for neither Japanese nor Ukrainian gallium production were available.
Recycled gallium, from GaAs scrap (produced both in wafer manufacturing and from old electronics), accounts for a major proportion of the metal in the market. Even back in 2005, the Mining Journal estimated that it "...may account for up to half the supply into the world market." There is no reason to think that the proportion now is any smaller. "However," according to a recent industry presentation on gallium, "it is virtually impossible to increase the recycled quantities. Because of the Ga value and the toxicity of As, this has already been optimized."
A number of primary gallium producers also recycle (and refine) gallium-containing scrap, often on either a toll conversion basis or having purchased it themselves. New GaAs scrap is recycled in the U.S. (in particular by Recapture Metals at its Blandings, Utah plant), Germany (by PPM - part of the Recylex Group [Bloomberg Ticker - RX:FP]), Japan and the U.K. (by MCP).
According to USGS figures, "World primary gallium production capacity in 2007 was estimated to be 184 metric tons; refinery capacity, 167 tons; and recycling capacity, 78 tons."
Having dropped from a high in mid-2007 to low at the end of 2008, the price of gallium has started to rise again.
Some Interesting Developments
There have been a number of quite interesting developments over the past several years involving the use of gallium. Two particular areas of use are of note: in solar cells and in the defense industry.
A recent brief story (January 20, 2009) on LowCarbonEconomy.com stated that, "The most efficient solar cells to date have been developed, by German scientists." The scientists claim that their solar cells are able to convert sunlight into electricity "at a rate of 41.1 per cent." Of particular interest is the fact that "their success was achieved by finding a new way to combine the component materials - gallium indium phosphate and gallium indium arsenide on a germanium substrate."
And only last year, in December 2008, Global Solar Energy, the Arizona-based solar cell manufacturing company, announced that the world's largest CIGS solar electric array - a 750 kW system - was now operational at its manufacturing facility in Tucson. (CIGS is copper indium gallium (di)selenide.)
If thin-film photovoltaics [TFPV] are the way forward for solar cells, then CIGS could well hold a key to success - albeit with a deal of work needing to be done on the way. While the silicon vs. CIGS debate continues, with strong arguments on both sides, it is perhaps worth noting that, should CIGS win the day (and all the many outstanding materials problems associated with it getting solved), the impact on gallium demand could be significant. Using CIGS, an estimated 15-30 tonnes just of gallium would be needed to produce 1,000 MW per year.
Because of their unique properties, there are currently, in a range of defense-related applications, no effective substitutes for either GaAs or GaN.
For example, in radar applications, three particular characteristics of gallium nitride make it particularly valuable: a very high output impedance, good substrate thermal conductivity and a breakdown electric field 10X greater than GaAs. In addition to radar, modern active array antennae (using GaN) in fighters and surveillance planes have the bandwidth and power to "perform offensive jamming and communications." In this context, the use of GaN will be particularly important in the development of amplifiers (used especially for jamming) that are both very high bandwidth and high power.
In the field of military communications, developing the use of GaN in high-power high-frequency [HPHF] electronic device technology, particularly for use in missiles, has been amongst the U.S. Department of Defense's recent initiatives.
In the past, a gallium alloy has been used, also in the plutonium pits (the core of an implosion weapon) of nuclear weapons to stabilize the allotropes (the different metal phases/forms) of the plutonium. (Carbon, for instance, has two allotropes: diamond and graphite.)
Gallium is also important for defense purposes not only because it can be used in specialized cameras to create images using electromagnetic radiation from the ultraviolet (UV) wavelengths (especially useful if you want to track missile launches, analyze shellfire, or, indeed, detect suspicious biological agents), but also because it can be employed in specially designed, and necessarily compact, shortwave infrared cameras for use, for example, either in space or in unmanned aerial vehicles [UAVs] or "drones."
Finally, the Department of Defense, amongst others, has been instrumental in providing funds for continuing research into both more efficient, and the more efficient use of, LEDs, especially those employing gallium.
However, while military interest in gallium, and particularly GaN, is sure to continue, as an article in compoundsemiconductor.net so rightly put it: "...the shroud of secrecy surrounding the defense market means that it is very hard to determine what dollar value the interest in the area is likely to turn into." It is obviously high enough, though, for a number of firms to want to participate in the market.
Currently there are no "pure" gallium plays. For all the main primary producers - and there are really only three (one of which is a joint venture between two privately owned companies) - gallium extraction is just one of a number of activities.
For secondary producers, the situation is similar, but with the additional factor that some of the main primary producers are also important secondary producers. For example, for Recylex, once again, gallium recycling is just one of many recycling activities.
Perhaps this is not surprising if you take into account that the actual size of the global gallium market - at today's prices - is probably only on the order of $110 million.
There is, currently, no primary gallium recovery in the U.S. And, unfortunately, any prospect of there being any soon, seems, in today's economic environment, to be receding rapidly. For those seeking primary gallium opportunities closer to home, unfortunately, the choices are dwindling.
Strategic Resource Acquisition Corporation (Bloomberg Ticker - SRZ/H:CN), which has zinc mines in Tennessee with, in the company's words, "Germanium and Gallium value-added byproducts," filed for Chapter 11 protection in mid-January 2009.
Gold Canyon Resources Inc. (Bloomberg Ticker - GCU:CN), another Canadian company, controls a 100% interest in the Cordero Gallium Project in north central Nevada. While the company describes it as "North America's largest known primary gallium occurrence," there is little to indicate that anything further has been done to exploit it following some initial drilling and evaluation in 2006. Indeed, in a recent communication, it was stated that, in light of what's going on in the financial markets, "...[the] Company has elected to suspend, at this time, the preparation of a preliminary feasibility study at the Cordero Gallium Project."
For those prepared to look a little further afield, and at a recent start-up operation for which gallium extraction is, again, just one aspect of its businesses, then Emerging Metals Limited (Bloomberg Ticker - EML:LN) could be of interest. One of company's first projects is the planned extraction, if it proves viable, of germanium, gallium and zinc from the slag produced by, and stockpiled from, the Tsumeb Smelter in the Oshikoto region of Namibia.
Although there appear to be some interesting prospects for more gallium being used in the likes of solar cells using CIGS, LEDs and some advanced defense applications, cell phones probably still remain their primary destination. (In 2006, some 56% of all gallium went into cell phones, with the next largest amount, some 17%, going into lighting.) On the demand side, therefore, in the present economic climate, there could be some challenges ahead for the metal. The corollary to this, however, is the fact that there do not seem to be many, if any, ways to gain significant, unalloyed, exposure to the business of primary gallium extraction.
Similarly, only alloyed exposure to the business of secondary gallium extraction appears currently possible, through recyclers such as Recylex. But, once again, as with the current primary metal extractors, gallium will only be one of a number of metals recycled.
With so few opportunities available in the metal itself, those still interested in its promises could do worse than look at the companies at the forefront in developing gallium's further use in either CIGS or LEDs.
Unfortunately, when it comes to defense applications, many of the contractors in this field will either be subsidiaries of larger companies or tightly held private firms. So, finding anything of interest may be difficult.
While industrial-scale chip manufacturing is another aspect entirely, looking laterally at gallium use could throw up some other interesting prospects. For example, now that Blu-ray has the field to itself, who is going to make all those blue lasers? They do use gallium!
Mining & Chemical Products Limited [MCP]
Minor Metals Trade Association [MMTA]
U.S. Geological Survey [USGS]