rare-earth absorbs NEEDED VERY FEW MINERALS
By: Thomas Unger
Diario El Comercio of November 17, 2009.
The technological development ideas have always preceded the invention, in many cases due to lack of appropriate materials. Leonardo delta wing had flown if instead of cane, canvas and rope, he would have duralumin tubes, steel wires and nylon. The basic design of motor cars Formula 1 dates from 1911, but metals, lubricants and fuels the time did not allow passing of 3,000 revolutions per minute, while passing the 16,000 today. In the digital age
our millions of electronic devices and infrastructure require materials with special characteristics. This is most noticeable when trying to produce in large scale artifacts ever smaller and lighter. Among the materials required, albeit in small quantities, is a leading metals group called rare earths. The name is not because they are scarce, but because the minerals are always combined in small quantities difficult to separate.
FAMILY
The family consists of 17 rare earth elements, all metals. Fifteen form a block in the periodic table (atomic number 57 to 61) called lanthanides, the other two elements, scandium and yttrium (atomic numbers 21 and 39), found elsewhere in the table but they closely resemble . For this reason, the International Union of Pure and Applied Chemistry (IUPAC) considers the elements that make up the rare earths are 17.
The first element of this family was discovered in 1787 in a black rock Ytterby the people of Sweden. Mineral analysis of Swedish chemists isolated several elements, among which was a they did not know, which they christened yttrium in honor to the town where he was found. By 1803 they had isolated another that cerium named in honor of the goddess Ceres, and was the first rare earth element identified as the lanthanides.
LASER TO OIL
The 15 elements from lanthanum, with atomic number 57, to lutetium, with atomic number 71, are similar in their physical characteristics and in their natural state are never alone. For physical and chemical characteristics that are similar in all have application in various electronic devices and as alloying elements, special features are metals and glass. Some examples may illustrate the variety of uses and the reason why it has increased the demand for rare earths.
Scandium (Sc), a silvery white metal discovered in 1869 in Sweden, with low weight and high melting point (1.541 ° C) is a component of some light alloy aerospace industry (aircraft MIG 21 and 29 is used). Small amounts are also used in halogen lamps and tubes of TV cameras. Yttrium (Y), although rare earth called, is 400 times more abundant in the earth's crust than silver, but is present in minerals in very small proportion. Interestingly, the rocks brought from the Moon has a relatively high content of yttrium. This metal is used in oxygen sensors (probe Delta) in the exhaust of automobiles, in the manufacture of light emitting diodes (LED) and the photographic lens glasses, among others.
Features similar to yttrium, lanthanum (La), is used in cigarette lighters and vacuum tubes. The film industry uses it for special optical glasses. Now a new use has attached great importance to lanthanum: in the nickel-metal hydride, such as those used by the Prius hybrid car. Cerium (Ce) is used in catalytic converters for automobiles, diesel fuel additives magnets and tungsten, among others.
The promethium (Pm) is an artificially obtained that NASA used in nuclear batteries. Samarium (Sm) is used for arc lights in cinema projectors in lasers and nuclear reactors. There are also magnets samarium in the headphones, electric guitars and other electronic instruments. Europium (Eu) is used in the manufacture of lasers, televisions and fluorescent lamps. Among its various uses are phosphorescent strips with euro banknotes to prevent counterfeiting.
Gadolinium (Gd) is used in TV tubes in certain types of computer memory and in alloy steel and chrome. Another use is an intravenous contrast agent for MRI. Terbium (Tb) is used in marine sonar sensors and deep green to the TV screens. Dysprosium (Dy) is used in the manufacture of lasers and compact discs, among others. The holmium (Ho) is the most magnetic of all known elements, so it is used in magnets and in some lasers and specialized microwave equipment. Erbium (Er) is a very important use in optical fiber transmission, which is also used in lasers to amplify the signal. The thulium ™
using X-ray and ytterbium (Yb) to produce gamma rays and steel alloys. Praseodymium (Pr) is also an amplifier for fiber optic lighting is used in coloring glass and optical. The most powerful permanent magnets are neodymium (Nd), so it is used for hard drives, headphones, microphones and electric guitars. Lens is also used in astronomy and the world's most powerful laser *. Lutetium (Lu) for their rarity and high price have fewer applications, but is always used in catalytic cracking of petroleum.
FUTURE Because
used in very small quantities of rare earth volumes consumed are relatively small. For example, neodymium, despite their many important applications, has a demand of only 7,000 tons a year, but growing. This is the case for all the rare earths. Until the 90's production was divided among China, USA, with a third each, and the remaining third divided mainly between Australia, Brazil, India and Sri Lanka. Due to cost, most mines have closed, and today 95% of production is in China, whose electronics industry uses two-thirds. For the remaining third, China is imposing quotas.
This situation and the demand for green technology has increased the search for mineral deposits containing rare earths. Despite the economic crisis are investing hundreds of million in this search. So far it has found new deposits in Australia and the mining companies are looking for in North America and South Africa. In South America, Chile and has deposits of rare earths and, given the similar geology of the Andes, we may have one, which would be a new source of wealth for our future. Britain to nuclear research has been built Helen, a neodymium-glass laser of a terawatt (one million million kW).
