The rare metal
The rarest metal in the world – one that very few found in nature. The discrepancy may arise from the fact that in the periodic system (Mendeleev compiled) there is a group of elements called "rare earth". In fact, it does not mean that their planet is not enough. Their number is often not less than that of other widespread metals such as copper, zinc, chrome and so on).
According to the Guinness Book of world records, the rarest metal on planet Earth – rhenium in the periodic table under 75 serial number. In fact, its discoverer can name the most periodic, as in compiling his table he predicted the existence of an element with relative atomic mass 180 (this was in 1870). But to prove the existence of this item and find it in practice it appeared not such simple task.
Many scientists spoke about their find since the times of the periodic, but in fact it wasn't true. And only in 1925 the German academic family Nodak opened this very rare metal.
Application of rhenium
Most people name this metal will not say anything. Because it is rare, and therefore, has a rather narrow spread. In industrial circles and among scientists rhenium is valued even more than other expensive metal – platinum. In particular, the blades of aircraft engines of modern aircraft are made of rhenium. In addition, the metal used in the creation of high-precision equipment, such as a gyroscope. Gasoline with a high content of octane was also synthesized by using this item. One of the modern developments filters of rhenium, which are installed on the exhaust pipe of the car.
Extraction of rhenium
Only here the use of rhenium is almost an impossible task, as there is no acute shortage in nature (what is rare). Until recently it was believed that on our planet there are deposits of this metal. And only in 1992 year, the South Kuril Islands, on the volcano Curly, it was discovered the world's only deposits of rhenium.
Rhenium is extracted from molybdenum and copper ores. To this concentrate is calcined. The procedure is very complex, and to obtain one kilogram of rhenium is required to process 12 thousand tons of ore. A year around the world, but produce only about 40 tons of this rare metal.