The rarest metal on Earth
We all know about metals such as aluminium, iron, chromium, platinum, gold. They have hearing and are the most common. But there are those metals that many people are not familiar with. Let’s find out what is the most rare metal on Earth exists, and what it has features.
Rhenium: a rare and persistent
The rarest metal in the world – such software can be considered as rhenium, whose appearance was predicted by Mendeleev in 1870. In those days, the great chemist claimed that soon will be discovered compound having the weight of an atom 180. However, many scientists struggled with this, but open a previously unknown metal it was only in 1925 Walter and IDA Noddack opened resistant material, which was named after the German river Rhine.
A lot of people do not even guess about the existence of this rare metal, but in the industry know about it firsthand – the value of rhenium is recognized much higher than the value of platinum. In 1992 it was discovered a rare Deposit of rhenium in Russia – a volcano Curly (South Kuril Islands). Today this field is in a stage of active formation. However, to obtain this the liquid metal is quite difficult to get a kilogram of material, to produce at least 2000 tons of molybdenum and copper ore. For the year to about forty tons of liquid metal.
Characteristics of liquid metal
This metal can be attributed to one of the most refractory. But despite this, it is quite plastic. Easy to forging, rolling, stretching in the wire. But plastic properties of the material depend directly on how clean is the resulting rhenium. Since this item is more plastic than tungsten, and the demand is a little higher. But the use of this metal it is sometimes difficult because of its high cost. Rhenium can even be considered the most expensive metal.For example, in 1969. for one kilo rare element in powder form need to pay about $ 1,300.
An important quality of rhenium is its excellent heat resistance. Actually this material to retain strength at 2000 degree temperatures much better than is characteristic of molybdenum, tungsten, niobium. In addition, the strength of rhenium is higher than that of metals difficult to melt. Rare metal has a high resistance to corrosion, which unites the material with the platinum.
In a compact form rhenium has silver color. If you store it at low temperatures, the years it will not lose the appearance and not fade. The oxidation of rhenium can be observed at a temperature range of 300 degrees, and a more intense oxidation will occur at a temperature over 600 degrees. This property means that the metal is much more resistant to oxidative process than tungsten or molybdenum, and is not prone to react with nitrogen and hydrogen.
The use of rhenium
Thanks to the combination of chemical and physical characteristics of this metal, it is used in those industries where the use of expensive metals are required to achieve the desired results. As a rule, rhenium is used in alloys, which in the end is cheaper than he. But directly the rhenium is used for the manufacture of important parts of small size. Also, rhenium is a coating of other metals.
Rhenium is used to create high-octane gasoline, the production of high-precision equipment, the production of filters in order to purify automobile exhaust. But the use of rhenium on a larger scale is nearly impossible because of its scarcity in nature and thus high cost.
Another rare element in the earth’s crust
This is recognized as to astatine, which is in the earth’s crust, according to scientists, contains only 0.16 oz. Officially inaugurated this element of the periodic table was in 1940. Characteristics of astatine study experimentally is quite difficult because of the small amount. However, this radioactive element is now of great interest to scientists because it was found that it can be used in the fight against cancer.