High-tech and low tech, boron's on the rise. But can you get access?
"Boron is a truly schizophrenic element. It's an element of complete frustration. It doesn't know what it wants to do. The outcome is something horribly complicated."
—Professor Artem R. Oganov, Stony Brook University, New York as quoted in the New York Times on Feb. 2, 2009
While boron may not know what it wants to do with itself (there are more than 200 naturally occurring boron-bearing minerals), we as humans certainly know what to do with it. We have been using it now, in different guises, for about 4,000 years. Estimates of the number of its different uses range anywhere from 300 to 500. And, currently, its most publicized use, if not its most useful, is in those rare-earth, neodymium-iron-boron magnets that go into wind turbines and other important industrial applications.
What Is Boron?
Designated number 5 (and on the top right-hand side) in the periodic table, and extraordinarily simple in atomic structure, boron is, however, one of those problematic elements categorized, along with antimony, arsenic, germanium, polonium (arguably), silicon and tellurium, as a metalloid; that is, it is neither true metal nor nonmetal. And this, perhaps, accounts for a great deal of its versatility.
Boron was discovered relatively recently—in 1808 by the triumvirate of England's Sir Humphrey Davy, and Joseph Louis Gay-Lussac and Louis-Jacques Thénard from France. It occurs naturally only in boron-bearing compounds, not conveniently lying around in pure ores, and is extremely difficult to separate and purify into its elemental form. Following false claims to have done so by chemist Henri Moissan, it was only in 1909 that William Weintraub actually produced 99 percent pure boron.
At low temperatures, crystalline boron is an insulator and, at higher temperatures a conductor. It is also highly refractory, with its melting and boiling points given by one source as 2,076 °C and 3,927 °C, respectively. (The Los Alamos National Laboratory gives its boiling point as 4,000 °C.)
Although ubiquitous, boron is still not particularly abundant in the Earth's crust, constituting only around 0.001 percent thereof—less than that of lead, but certainly more than that of hafnium, beryllium and tin. And indeed, significant, useful deposits of borates (the form in which it is most usually found) are few and, literally, far between.
The largest borate deposits currently being mined are in California's Death Valley and in central and western Turkey, with Argentina, Chile, Turkey and the U.S. constituting the world's four largest producers of boron minerals.
Source: U.S. Geological Survey (USGS)