Rare earths

Japanese researchers have reported the discovery of vast deposits of rare earth minerals. The discovery was made by a team led by Yasuhiro Kato, an associate professor of earth science at the University of Tokyo, and included researchers from the Japan Agency for Marine-Earth Science and Technology. The deposits are in international waters east and west of Hawaii, and east of Tahiti in French Polynesia at depths of 3,500 to 6,000 metres (11,500-20,000 ft) below the ocean surface.

Currently, China supplies around 95 percent of the world’s demand for rare earth minerals. Over the past few years, it has tightened its grip on the precious resource by restricting exports. This has sparked an increasing number of international search and mining projects for the minerals.

The recent find is expected to come as a relief to Western nations, as dependence on rare earths grows with the advancement of modern life. It can be said that rare earths are the basis and drive of all modern technologies. Rare earths are a collection of 17 elements in the periodic table. They are found in the earth’s crust and are not as rare as the name would have one believe. They are usually bound to other, sometimes radioactive elements from which they must be separated. Technologies developed in the mid 20th century have made it easier to do this, paving the way for science to exploit their properties.

Ubiquitous rare earth elements

Today, rare earths can be found in just about all gadgets in every-day life, from flat-screen television sets and iPods to LED lights. One of them, Neodymium, is the key element used in today’s most powerful magnets. Klaus-Martin Blechert from the magnet company Deutsche Techna explains that large-scale deployment has only been around for about 15 years. He adds that advancements using such batteries continue "because these magnets have much better magnetic properties in smaller quantities. That allows us to make things much smaller. And it also allows the magnets to be used in highly specialized applications, for example in computers, hard discs and mobile phones, to name a few."

Modern military technologies are also dependent upon the use of rare earths. Mark Brown, CFO of the company Rare Element Resources in Canada, says such technologies would be unthinkable without rare earths. Some of the elements that are more in demand these days are Lanthanum, Neodymium and Seryium. "These ‘smart bombs’ you hear about, some of the stealth fighter and stealth ship technologies - many of those technologies use these," Brown adds, saying it is no wonder China’s grip on rare earths has worried nations dependent on such technologies.

Green technologies and environmental concerns

In other areas, especially that of green technologies, there is no question that humankind's dependence on rare earths is increasing steadily. For instance, no fewer than 15 kilos of rare earths are required for the batteries of a hybrid car. But many experts are concerned with the ecological impact of mining and producing rare earths. Herman Wotruba, professor and head of research at RWTH Aachen’s Department of Mineral Processing says it is vital to separate out radio active elements. He says, while there are processes that allow the separation of Uranium and Thorium from the rare earths, "you have Uranium and Thorium left over that has to be disposed of or stored somewhere. And the question is: how well is this being done? Another question is: can there be radioactive leakage during processing if there is no proper controlling?"

He says that the equipment and technology used in mining in China is behind Western standards. Not only that, but Chinese regulations are also cause for concern. But Michael Meyer, professor for Mineralogy and Geochemistry at Aachen's technical university, RWTH, dismisses concerns and says mining and processing rare earths is like the treatment of any other mineral: "Whether or not the processing of rare earths poses a problem for the environment depends on regulations and the technical standards used. Basically, if the best available technology is used, no harm can really be done to the environment." But there are concerns rare earth production is harmful to the environment if the correct procedures are ignored.

Need for research

Though rare earths are mainly used in highly technologically advanced applications, they have other uses as well. Professor Ewald Schnug of the Institute of Animal Nutrition at Germany’s Federal Agricultural Research Centre in Braunschweig has studied the effects of rare earths in agriculture and cattle farming. Agriculture scientists worldwide have been looking for alternatives to growth hormones (such as antibiotics) for cattle to increase returns. One such alternative is the use of rare earths, and China has a long track record using them in fertilizers and animal feed. But Schnug believes using the elements for these purposes is highly risky because of the radioactivity involved. In animal feed, he compares it to the use of copper: "You feed them concentrations which are nearly toxic but the organism reacts with increased metabolic rates to it. As a result, this can produce faster or more intensive growth. So it might be some sort of a stress reaction, but another idea is that it is some sort of a promoter of the calcium metabolism in the organism." Schnug adds that, though some in China are using this kind of growth enhancer, it is not yet officially recommended on a national scale because the full impact has yet to be studied.

For all the uses of rare earths, it is clear that the progress in the world of today will continue to be dependent upon them. Many countries have started investing in costly and time-consuming exploration projects to set up their own production and thus reduce dependence on Chinese rare earths. Countries such as South Africa, Australia, the USA and Canada are expected to be able to produce around 50,000 tons of rare earths by 2014. But being that world demand is expected to grow to 180,000 tons annually, it looks like exploration like the successful Japanese efforts in the Pacific will become more and more important in the coming years.

Author: Sarah Berning
Editor: Grahame Lucas