April 6, 2013 § Leave a comment
“Rare earths” are vital components in the production of a range of high technology equipment. The elements are integral to modern life, and are used in everything from disc drives, hybrid cars, smartphones, catalytic converters, and sunglasses to lasers and aircraft used by the military.
Japan is celebrating the recent find of an “astronomically” high level of rare earth deposits at the bottom of the Pacific Ocean, a discovery which will further undermine China’s failing attempts to control the global supply of the substances, Phil Muncaster wrote on March 25 in The Register’s (register.co.uk) science section.
China claims it holds less than a third of global rare earth reserves despite providing more than 90 per cent of the world’s supply.
Rare earth elements or rare earth metals, according to Wikipedia, are a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrium. Scandium and yttrium are considered rare earth elements since they tend to occur in the same ore deposits as the lanthanides and exhibit similar chemical properties.
Despite their name, rare earth elements (with the exception of the radioactive promethium) are relatively plentiful in the Earth’s crust, with cerium being the 25th most abundant element at 68 parts per million (similar to copper). However, because of their geochemical properties, rare earth elements are typically dispersed and not often found concentrated as rare earth minerals in economically exploitable ore deposits. It was the very scarcity of these minerals (previously called “earths”) that led to the term “rare earth”. The first such mineral discovered was gadolinite, a compound of cerium, yttrium, iron, silicon and other elements. This mineral was extracted from a mine in the village of Ytterby in Sweden; several of the rare earth elements bear names derived from this location.
All of which reminds me of Texas’ only rare earth deposits, those of Barringer Hill, now far below Lake Buchanan (the first of the Colorado River’s Highland Lakes chain), near the dam itself. Only a small mound of rock and dirt 34 feet taller than the surrounding country, Barringer Hill was not even remotely interesting in appearance, but in the words of the U.S. Geological Survey, “Few if any deposits in the world, and certainly no others in America, outside of the localities where monazite is found, have yielded such quantities of rare earth metals as that at Barringer Hill.”
The Japanese deposits, Muncaster’s article continues, were found around 5.8 km under the ocean surface near Minami Torishima island southeast of Tokyo.
“We detected an astronomically high level of rare earth minerals in the mud we sampled,” Tokyo University boffin Yasuhiro Kato told Reuters.
“When researchers brought back the data to me, I thought they must have made a mistake, the levels were so high. The fact is this discovery could help supply Japan with 60 per cent of its annual needs merely with the contents of a single vessel.”
The find follows a much larger discovery by Japanese marine researchers in the Pacific two years ago and if the rare earths can be extracted cheaply enough, it could crucially give Tokyo the tactical upper hand over China in the on-going cat-and-mouse game between the two over supplies.
Beijing halted exports to Japan in September 2010 after a maritime dispute and has actively restricted exports to all countries since in a bid to drive up prices and force manufacturing investment onto its shores.
However, despite being investigated by the WTO for such policies, China has suffered in recent months as a slowdown in global demand combined with other countries re-starting their own mining operations, has sent prices tumbling.
In October last year, its largest mining company for light rare earths, Inner Mongolia Baotou Steel Rare Earth Hi-Tech Company, was forced to suspend operations for a month to let demand pick up. Japan takes more than half of China’s supply but is thought to have imported just 10,000 tons in 2012 – its lowest volume in a decade.
While the recent undersea discovery will be well-received in Tokyo, it’s unlikely to have any big repercussions in the near term, short of forcing China to keep its prices low.
The U.S. Geological Survey has looked at all known national reserves of the elements as part of a larger assessment of the threat posed to defense by limited rare earth supplies.
It found that the domestic pipeline is “rather thin.” The U.S. boasts the third largest reserves (13 million tons) in the world after China and the nations that were formerly part of the Soviet Union. But the only rare earths mines the US has ever operated, are currently inactive, with the exception of the mine at Mountain Pass, California, discovered in 1949. Once the largest and most profitable rare-earth mine in the world, rare-earth mining began there in the early 1950s, and by the mid-1980s the mine supplied 60 percent of global demand and 100 percent of U.S. needs. But as Chinese production increased, operations at Mountain Pass dwindled, until 2012, when production ramped up dramatically in the face of Chinese attempts to manipulate the world market to its advantage.
Now, back to Barringer Hill. Barringer Hill was named for John Barringer, a carpenter who acquired the land in 1886 when its owner was unable to pay Barringer $50 for a house he had built for the man. At that time, the Llano area was gripped with dreams of mineral wealth, especially iron. A few months later, Barringer, while out prospecting his newly acquired land, stumbled upon an outcropping of heavy, greenish-black ore. No one in the neighborhood knew what the mineral was and later that year, Professor N.J. Badu of Llano sent ore samples to Philadelphia and New York. Meanwhile Mr. Barringer had taken out a quantity of gadolinite estimated at 800 to 1,200 pounds, which was largely picked up and carried off by persons in the neighborhood as curiosities. Some of the choicer pieces, showing crystal form, found their way into various museums. Specimens were sent to a number of places before it was finally identified.
The samples were found to be composed primarily of a radioactive yttria mineral, known as gadolinite, that had previously only been found in small amounts in Russia and Norway. Yttria minerals were extremely valuable. In 1887, pure yttrium brought $144 an ounce, at a time when pure gold brought only $19 an ounce on the London exchange. The minerals from this deposit were so valuable that they were wrapped in tissue paper, packed in iron-bound boxes, and shipped by Wells Fargo express at 100 pounds a box. At best, obtaining each pound of ore cost $10.00.
The discovery of gadolinite at Barringer Hill attracted the interest of Thomas Edison and George Westinghouse. William E. Hidden, a Newark, New Jersey, mineralogist with connections to both companies read a newspaper account about the discovery and obtained a piece. At that time, Edison and Westinghouse were looking for gadolinite to use in the creation of a filament for electric light bulbs but had found no accessible sources of the mineral. Hidden sent Dr. William Niven, a Scottish born Texan, to investigate Barringer Hill in 1889. Niven identified forty-seven minerals there, including five previously unknown rare earth elements.
Edison experimented with all 47 Barringer Hill minerals, but by 1903, the company could find no use for any of them. Meanwhile, German chemist Hermann Nernst, working for Westinghouse, had developed a street lamp that used raw gadolinite as a filament. Nernst had patented the lamp that bore his name in 1897, but his original design for the lamp was commercially useless, because the lamp had a life of only two hours. Another Westinghouse engineer, Marshall Hank, was able to increase this number to 700 hours. The improved lamp’s design featured a filament consisting of 25 percent yttria and 75 percent zirconia. These ingredients were made into a paste, squirted into strips, baked, and then cut into the proper lengths. When the mixture was cold, it was nonconductive, but after being heated, it became a conductor that gave off a brilliant light with wavelengths penetrating deep into the infrared.
With its technical problems solved, the Nernst Lamp Company decided to put the lamp into production and bought Barringer Hill through William E. Hidden.
George Westinghouse had developed and introduced the Nernst lamp to the commercial market in the United States, organizing the Nernst Lamp Company in 1901. Production took place in Pittsburg in a five-story factory building with a total floor area of 101,000 square feet. By 1904 a total of over 130,000 Nernst glowers had been placed in service throughout the country.
During the winter of 1902-03, the Nernst Lamp Company sent Hidden to begin excavation. In 1903, Marshall Hanks, the engineer who had improved the Nernst Lamp, arrived to run the mining operation.
A little gadolinite went a very long way in those days, and only sporadic mining was necessary. When large-scale mining began, it lasted only a year. The incandescent light bulb had been invented, and the need for gadolinite was fading, in the face of the much cheaper wire filament that would soon become the essential element in light bulbs for the next century. The Barringer Hill mine ceased large-scale operations in 1904. Only sporadic mining was done at Barringer Hill thereafter and it was one of the first areas to be covered by Lake Buchanan.
The demand for rare earth minerals lay rather fallow from that point until the 1950s and the opening of the Mountain Pass mine, when their current modern usages began.
The story of Barringer Hill is told at length in Hill Country, in the chapter, “Hermit of the Hills/The Highland Lakes.”